Attribute.GetCustomAttributes Método

Definição

Recupera um array dos atributos personalizados aplicados a um assembly, módulo, membro de tipo ou parâmetro de método.

Sobrecargas

Name Description
GetCustomAttributes(ParameterInfo, Boolean)

Recupera um array dos atributos personalizados aplicados a um parâmetro de método. Os parâmetros especificam o parâmetro do método e se deve pesquisar antepassados do parâmetro do método.

GetCustomAttributes(MemberInfo, Type, Boolean)

Recupera um array dos atributos personalizados aplicados a um membro de um tipo. Os parâmetros especificam o membro, o tipo do atributo personalizado a procurar e se deve procurar antepassados do membro.

GetCustomAttributes(ParameterInfo, Type, Boolean)

Recupera um array dos atributos personalizados aplicados a um parâmetro de método. Os parâmetros especificam o parâmetro do método, o tipo do atributo personalizado a procurar e se deve procurar antepassados do parâmetro do método.

GetCustomAttributes(Module, Type, Boolean)

Recupera um array dos atributos personalizados aplicados a um módulo. Os parâmetros especificam o módulo, o tipo do atributo personalizado a procurar e uma opção de pesquisa ignorada.

GetCustomAttributes(MemberInfo, Type)

Recupera um array dos atributos personalizados aplicados a um membro de um tipo. Os parâmetros especificam o membro e o tipo do atributo personalizado a procurar.

GetCustomAttributes(Assembly, Type, Boolean)

Recupera um array dos atributos personalizados aplicados a uma assembleia. Os parâmetros especificam a montagem, o tipo do atributo personalizado a procurar e uma opção de pesquisa ignorada.

GetCustomAttributes(Module, Type)

Recupera um array dos atributos personalizados aplicados a um módulo. Os parâmetros especificam o módulo e o tipo do atributo personalizado a procurar.

GetCustomAttributes(ParameterInfo, Type)

Recupera um array dos atributos personalizados aplicados a um parâmetro de método. Os parâmetros especificam o parâmetro do método e o tipo do atributo personalizado a procurar.

GetCustomAttributes(MemberInfo, Boolean)

Recupera um array dos atributos personalizados aplicados a um membro de um tipo. Os parâmetros especificam o membro, o tipo do atributo personalizado a procurar e se deve procurar antepassados do membro.

GetCustomAttributes(Assembly, Type)

Recupera um array dos atributos personalizados aplicados a uma assembleia. Os parâmetros especificam a montagem e o tipo do atributo personalizado a procurar.

GetCustomAttributes(Assembly, Boolean)

Recupera um array dos atributos personalizados aplicados a uma assembleia. Os parâmetros especificam a montagem e uma opção de pesquisa ignorada.

GetCustomAttributes(ParameterInfo)

Recupera um array dos atributos personalizados aplicados a um parâmetro de método. Um parâmetro especifica o parâmetro do método.

GetCustomAttributes(Module)

Recupera um array dos atributos personalizados aplicados a um módulo. Um parâmetro especifica o módulo.

GetCustomAttributes(MemberInfo)

Recupera um array dos atributos personalizados aplicados a um membro de um tipo. Um parâmetro especifica o membro.

GetCustomAttributes(Assembly)

Recupera um array dos atributos personalizados aplicados a uma assembleia. Um parâmetro especifica a montagem.

GetCustomAttributes(Module, Boolean)

Recupera um array dos atributos personalizados aplicados a um módulo. Os parâmetros especificam o módulo e uma opção de pesquisa ignorada.

GetCustomAttributes(ParameterInfo, Boolean)

Recupera um array dos atributos personalizados aplicados a um parâmetro de método. Os parâmetros especificam o parâmetro do método e se deve pesquisar antepassados do parâmetro do método.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::ParameterInfo ^ element, bool inherit);
public static Attribute[] GetCustomAttributes(System.Reflection.ParameterInfo element, bool inherit);
static member GetCustomAttributes : System.Reflection.ParameterInfo * bool -> Attribute[]
Public Shared Function GetCustomAttributes (element As ParameterInfo, inherit As Boolean) As Attribute()

Parâmetros

element
ParameterInfo

Um objeto derivado da ParameterInfo classe que descreve um parâmetro de um membro de uma classe.

inherit
Boolean

Se true, especifica também procurar os antepassados de element por atributos personalizados.

Devoluções

Um Attribute array que contenha os atributos personalizados aplicados a element, ou um array vazio se não existirem tais atributos personalizados.

Exceções

A Member propriedade de element é null.

element é null.

Um tipo de atributo personalizado não pode ser carregado.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando a ParameterInfo como parâmetro.

using System;
using System.Reflection;
using System.ComponentModel;

namespace CustAttrs5CS {
    public class AClass {
        public void ParamArrayAndDesc(
            // Add ParamArray (with the keyword) and Description attributes.
            [Description("This argument is a ParamArray")]
            params int[] args)
        {}
    }

    class DemoClass {
        static void Main(string[] args) {
            // Get the Class type to access its metadata.
            Type clsType = typeof(AClass);
            // Get the type information for the method.
            MethodInfo mInfo = clsType.GetMethod("ParamArrayAndDesc");
            if (mInfo != null) {
                // Get the parameter information.
                ParameterInfo[] pInfo = mInfo.GetParameters();
                if (pInfo != null) {
                    // Iterate through all the attributes for the parameter.
                    foreach(Attribute attr in
                        Attribute.GetCustomAttributes(pInfo[0])) {
                        // Check for the ParamArray attribute.
                        if (attr.GetType() == typeof(ParamArrayAttribute))
                            Console.WriteLine("Parameter {0} for method {1} " +
                                "has the ParamArray attribute.",
                                pInfo[0].Name, mInfo.Name);
                        // Check for the Description attribute.
                        else if (attr.GetType() ==
                            typeof(DescriptionAttribute)) {
                            Console.WriteLine("Parameter {0} for method {1} " +
                                "has a description attribute.",
                                pInfo[0].Name, mInfo.Name);
                            Console.WriteLine("The description is: \"{0}\"",
                                ((DescriptionAttribute)attr).Description);
                        }
                    }
                }
            }
        }
    }
}

/*
 * Output:
 * Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
 * Parameter args for method ParamArrayAndDesc has a description attribute.
 * The description is: "This argument is a ParamArray"
 */
open System
open System.Reflection
open System.ComponentModel

type AClass() =
    member _.ParamArrayAndDesc(
        // Add ParamArray and Description attributes.
        [<Description "This argument is a ParamArray">]
        [<ParamArray>]
        args: int[]) = ()

// Get the Class type to access its metadata.
let clsType = typeof<AClass>

// Get the type information for the method.
let mInfo = clsType.GetMethod "ParamArrayAndDesc"
if mInfo <> null then
    // Get the parameter information.
    let pInfo = mInfo.GetParameters()
    if pInfo <> null then
        // Iterate through all the attributes for the parameter.
        for attr in Attribute.GetCustomAttributes pInfo[0] do
            match attr with 
            // Check for the ParamArray attribute.
            | :? ParamArrayAttribute ->
                printfn $"Parameter {pInfo[0].Name} for method {mInfo.Name} has the ParamArray attribute."
                                
            // Check for the Description attribute.
            | :? DescriptionAttribute as attr ->
                printfn $"Parameter {pInfo[0].Name} for method {mInfo.Name} has a description attribute."
                printfn $"The description is: \"{attr.Description}\""
            | _ -> ()

// Output:
// Parameter args for method ParamArrayAndDesc has a description attribute.
// The description is: "This argument is a ParamArray"
// Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
Imports System.Reflection
Imports System.ComponentModel

Module DemoModule
    Public Class AClass
        ' Add Description and ParamArray (with the keyword) attributes.
        Public Sub ParamArrayAndDesc( _
            <Description("This argument is a ParamArray")> _
            ByVal ParamArray args() As Integer)
        End Sub
    End Class

    Sub Main()
        ' Get the Class type to access its metadata.
        Dim clsType As Type = GetType(AClass)
        ' Get the type information for the method.
        Dim mInfo As MethodInfo = clsType.GetMethod("ParamArrayAndDesc")
        ' Get the Parameter information for the method.
        Dim pInfo() As ParameterInfo = mInfo.GetParameters()
        Dim attr As Attribute
        ' Iterate through each attribute of the parameter.
        For Each attr In Attribute.GetCustomAttributes(pInfo(0))
            ' Check for the ParamArray attribute.
            If TypeOf attr Is ParamArrayAttribute Then
                ' Convert the attribute to access its data.
                Dim paAttr As ParamArrayAttribute = _
                    CType(attr, ParamArrayAttribute)
                Console.WriteLine("Parameter {0} for method {1} has the " + _
                    "ParamArray attribute.", pInfo(0).Name, mInfo.Name)
            ' Check for the Description attribute.
            ElseIf TypeOf attr Is DescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim descAttr As DescriptionAttribute = _
                    CType(attr, DescriptionAttribute)
                Console.WriteLine("Parameter {0} for method {1} has a description " + _
                    "attribute. The description is:", pInfo(0).Name, mInfo.Name)
                Console.WriteLine(descAttr.Description)
            End If
        Next
    End Sub
End Module

' Output:
' Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
' Parameter args for method ParamArrayAndDesc has a description attribute. The description is:
' This argument is a ParamArray

Observações

Se element representa um parâmetro num método de um tipo derivado, o valor de retorno inclui os atributos personalizados herdáveis aplicados ao mesmo parâmetro nos métodos base sobrepostos.

Aplica-se a

GetCustomAttributes(MemberInfo, Type, Boolean)

Recupera um array dos atributos personalizados aplicados a um membro de um tipo. Os parâmetros especificam o membro, o tipo do atributo personalizado a procurar e se deve procurar antepassados do membro.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::MemberInfo ^ element, Type ^ type, bool inherit);
public static Attribute[] GetCustomAttributes(System.Reflection.MemberInfo element, Type type, bool inherit);
static member GetCustomAttributes : System.Reflection.MemberInfo * Type * bool -> Attribute[]
Public Shared Function GetCustomAttributes (element As MemberInfo, type As Type, inherit As Boolean) As Attribute()

Parâmetros

element
MemberInfo

Um objeto derivado da MemberInfo classe que descreve um construtor, evento, corpo, método ou propriedade membro de uma classe.

typeattributeType
Type

O tipo, ou um tipo base, do atributo personalizado a procurar.

inherit
Boolean

Se true, especifica também procurar os antepassados de element por atributos personalizados.

Devoluções

Um array que contém os atributos personalizados do tipo type aplicados a element, ou um array vazio se não existirem Attribute tais atributos personalizados.

Exceções

element ou type é null.

type não deriva de Attribute.

element não é um construtor, método, propriedade, evento, tipo ou campo.

Um tipo de atributo personalizado não pode ser carregado.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando a MemberInfo como parâmetro.

using System;
using System.Reflection;
using System.Security;
using System.Runtime.InteropServices;

namespace CustAttrs4CS
{

    // Define an enumeration of Win32 unmanaged types
    public enum UnmanagedType
    {
        User,
        GDI,
        Kernel,
        Shell,
        Networking,
        Multimedia
    }

    // Define the Unmanaged attribute.
    public class UnmanagedAttribute : Attribute
    {
        // Storage for the UnmanagedType value.
        protected UnmanagedType thisType;

        // Set the unmanaged type in the constructor.
        public UnmanagedAttribute(UnmanagedType type)
        {
            thisType = type;
        }

        // Define a property to get and set the UnmanagedType value.
        public UnmanagedType Win32Type
        {
            get { return thisType; }
            set { thisType = Win32Type; }
        }
    }

    // Create a class for an imported Win32 unmanaged function.
    public class Win32 {
        [DllImport("user32.dll", CharSet = CharSet.Unicode)]
        public static extern int MessageBox(int hWnd, String text,
            String caption, uint type);
    }

    public class AClass {
        // Add some attributes to Win32CallMethod.
        [Obsolete("This method is obsolete. Use managed MsgBox instead.")]
        [Unmanaged(UnmanagedType.User)]
        public void Win32CallMethod()
        {
            Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0);
        }
    }

    class DemoClass {
        static void Main(string[] args)
            {
            // Get the AClass type to access its metadata.
            Type clsType = typeof(AClass);
            // Get the type information for Win32CallMethod.
            MethodInfo mInfo = clsType.GetMethod("Win32CallMethod");
            if (mInfo != null)
            {
                // Iterate through all the attributes of the method.
                foreach(Attribute attr in
                    Attribute.GetCustomAttributes(mInfo)) {
                    // Check for the Obsolete attribute.
                    if (attr.GetType() == typeof(ObsoleteAttribute))
                    {
                        Console.WriteLine("Method {0} is obsolete. " +
                            "The message is:",
                            mInfo.Name);
                        Console.WriteLine("  \"{0}\"",
                            ((ObsoleteAttribute)attr).Message);
                    }

                    // Check for the Unmanaged attribute.
                    else if (attr.GetType() == typeof(UnmanagedAttribute))
                    {
                        Console.WriteLine(
                            "This method calls unmanaged code.");
                        Console.WriteLine(
                            String.Format("The Unmanaged attribute type is {0}.",
                                          ((UnmanagedAttribute)attr).Win32Type));
                        AClass myCls = new AClass();
                        myCls.Win32CallMethod();
                    }
                }
            }
        }
    }
}

/*

This code example produces the following results.

First, the compilation yields the warning, "... This method is
obsolete. Use managed MsgBox instead."
Second, execution yields a message box with a title of "Caution!"
and message text of "This is an unmanaged call."
Third, the following text is displayed in the console window:

Method Win32CallMethod is obsolete. The message is:
  "This method is obsolete. Use managed MsgBox instead."
This method calls unmanaged code.
The Unmanaged attribute type is User.

*/
open System
open System.Runtime.InteropServices

// Define an enumeration of Win32 unmanaged types
type UnmanagedType =
    | User = 0
    | GDI = 1
    | Kernel = 2
    | Shell = 3
    | Networking = 4
    | Multimedia = 5

// Define the Unmanaged attribute.
type UnmanagedAttribute(unmanagedType) =
    inherit Attribute()
    
    // Define a property to get and set the UnmanagedType value.
    member val Win32Type = unmanagedType with get, set

// Create a module for an imported Win32 unmanaged function.
module Win32 =
    [<DllImport("user32.dll", CharSet = CharSet.Unicode)>]
    extern int MessageBox(IntPtr hWnd, String text, String caption, uint ``type``)

type AClass() =
    // Add some attributes to Win32CallMethod.
    [<Obsolete "This method is obsolete. Use managed MsgBox instead.">]
    [<Unmanaged(UnmanagedType.User)>]
    member _.Win32CallMethod () =
        Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0u)

// Get the AClass type to access its metadata.
let clsType = typeof<AClass>
// Get the type information for Win32CallMethod.
let mInfo = clsType.GetMethod "Win32CallMethod"
if mInfo <> null then
    // Iterate through all the attributes of the method.
    for attr in Attribute.GetCustomAttributes mInfo do
        match attr with 
        // Check for the Obsolete attribute.
        | :? ObsoleteAttribute as attr ->
            printfn $"Method {mInfo.Name} is obsolete. The message is:"
            printfn $"  \"{attr.Message}\""

        // Check for the Unmanaged attribute.
        | :? UnmanagedAttribute as attr ->
            printfn "This method calls unmanaged code."
            printfn $"The Unmanaged attribute type is {attr.Win32Type}."
            let myCls = AClass()
            myCls.Win32CallMethod() |> ignore
        | _ -> ()

// This code example produces the following results.
//
// First, the compilation yields the warning, "... This method is
// obsolete. Use managed MsgBox instead."
// Second, execution yields a message box with a title of "Caution!"
// and message text of "This is an unmanaged call."
// Third, the following text is displayed in the console window:

// Method Win32CallMethod is obsolete. The message is:
//   "This method is obsolete. Use managed MsgBox instead."
// This method calls unmanaged code.
// The Unmanaged attribute type is User.
Imports System.Reflection
Imports System.Security
Imports System.Runtime.InteropServices

' Define an enumeration of Win32 unmanaged types
Public Enum UnmanagedType
    User
    GDI
    Kernel
    Shell
    Networking
    Multimedia
End Enum 'UnmanagedType

' Define the Unmanaged attribute.
Public Class UnmanagedAttribute 
             Inherits Attribute

    ' Storage for the UnmanagedType value.
    Protected thisType As UnmanagedType
    
    ' Set the unmanaged type in the constructor.
    Public Sub New(ByVal type As UnmanagedType) 
        thisType = type
    End Sub
    
    ' Define a property to get and set the UnmanagedType value.
    Public Property Win32Type() As UnmanagedType 
        Get
            Return thisType
        End Get
        Set
            thisType = Win32Type
        End Set
    End Property
End Class

' Create a class for an imported Win32 unmanaged function.
Public Class Win32
    <DllImport("user32.dll", CharSet:=CharSet.Unicode)> _
    Public Shared Function MessageBox(ByVal hWnd As Integer, _
                                      ByVal Text As String, _
                                      ByVal caption As String, _
                                      ByVal type As Integer) As Integer
    End Function 'MessageBox
End Class

Public Class AClass
    ' Add some attributes to Win32CallMethod.
    <Obsolete("This method is obsolete. Use managed MsgBox instead."), _
     Unmanaged(UnmanagedType.User)>  _
    Public Sub Win32CallMethod() 
        Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0)    
    End Sub
End Class

Class DemoClass
    Shared Sub Main(ByVal args() As String) 
        ' Get the AClass type to access its metadata.
        Dim clsType As Type = GetType(AClass)
        ' Get the type information for Win32CallMethod.
        Dim mInfo As MethodInfo = clsType.GetMethod("Win32CallMethod")
        If Not (mInfo Is Nothing) Then
            ' Iterate through all the attributes of the method.
            Dim attr As Attribute
            For Each attr In  Attribute.GetCustomAttributes(mInfo)
                ' Check for the Obsolete attribute.
                If attr.GetType().Equals(GetType(ObsoleteAttribute)) Then
                    Console.WriteLine("Method {0} is obsolete. The message is:", mInfo.Name)
                    Console.WriteLine("  ""{0}""", CType(attr, ObsoleteAttribute).Message)
                ' Check for the Unmanaged attribute.
                ElseIf attr.GetType().Equals(GetType(UnmanagedAttribute)) Then
                    Console.WriteLine("This method calls unmanaged code.")
                    Console.WriteLine( _
                            String.Format("The Unmanaged attribute type is {0}.", _
                            CType(attr, UnmanagedAttribute).Win32Type))
                    Dim myCls As New AClass()
                    myCls.Win32CallMethod()
                End If
            Next attr
        End If
    End Sub
End Class

'
'This code example produces the following results. 
'
'First, the compilation yields the warning, "... This method is 
'obsolete. Use managed MsgBox instead."
'Second, execution yields a message box with a title of "Caution!" 
'and message text of "This is an unmanaged call." 
'Third, the following text is displayed in the console window:
'
'Method Win32CallMethod is obsolete. The message is:
'  "This method is obsolete. Use managed MsgBox instead."
'This method calls unmanaged code.
'The Unmanaged attribute type is User.
'

Observações

O valor de retorno contém os atributos personalizados para os antepassados de element se inherit for true.

Note

A partir do .NET Framework versão 2.0, este método devolve atributos de segurança nos métodos, construtores e tipos se os atributos estiverem armazenados no novo formato de metadados. Assemblies compilados com a versão 2.0 ou posterior utilizam o novo formato. Assemblies dinâmicos e assemblies compilados com versões anteriores do .NET Framework utilizam o antigo formato XML. Ver Emissão de Atributos de Segurança Declarativa.

Aplica-se a

GetCustomAttributes(ParameterInfo, Type, Boolean)

Recupera um array dos atributos personalizados aplicados a um parâmetro de método. Os parâmetros especificam o parâmetro do método, o tipo do atributo personalizado a procurar e se deve procurar antepassados do parâmetro do método.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::ParameterInfo ^ element, Type ^ attributeType, bool inherit);
public static Attribute[] GetCustomAttributes(System.Reflection.ParameterInfo element, Type attributeType, bool inherit);
static member GetCustomAttributes : System.Reflection.ParameterInfo * Type * bool -> Attribute[]
Public Shared Function GetCustomAttributes (element As ParameterInfo, attributeType As Type, inherit As Boolean) As Attribute()

Parâmetros

element
ParameterInfo

Um objeto derivado da ParameterInfo classe que descreve um parâmetro de um membro de uma classe.

attributeType
Type

O tipo, ou um tipo base, do atributo personalizado a procurar.

inherit
Boolean

Se true, especifica também procurar os antepassados de element por atributos personalizados.

Devoluções

Um array que contém os atributos personalizados do tipo attributeType aplicados a element, ou um array vazio se não existirem Attribute tais atributos personalizados.

Exceções

element ou attributeType é null.

attributeType não deriva de Attribute.

Um tipo de atributo personalizado não pode ser carregado.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando a ParameterInfo como parâmetro.

using System;
using System.Reflection;
using System.ComponentModel;

namespace CustAttrs5CS {
    public class AClass {
        public void ParamArrayAndDesc(
            // Add ParamArray (with the keyword) and Description attributes.
            [Description("This argument is a ParamArray")]
            params int[] args)
        {}
    }

    class DemoClass {
        static void Main(string[] args) {
            // Get the Class type to access its metadata.
            Type clsType = typeof(AClass);
            // Get the type information for the method.
            MethodInfo mInfo = clsType.GetMethod("ParamArrayAndDesc");
            if (mInfo != null) {
                // Get the parameter information.
                ParameterInfo[] pInfo = mInfo.GetParameters();
                if (pInfo != null) {
                    // Iterate through all the attributes for the parameter.
                    foreach(Attribute attr in
                        Attribute.GetCustomAttributes(pInfo[0])) {
                        // Check for the ParamArray attribute.
                        if (attr.GetType() == typeof(ParamArrayAttribute))
                            Console.WriteLine("Parameter {0} for method {1} " +
                                "has the ParamArray attribute.",
                                pInfo[0].Name, mInfo.Name);
                        // Check for the Description attribute.
                        else if (attr.GetType() ==
                            typeof(DescriptionAttribute)) {
                            Console.WriteLine("Parameter {0} for method {1} " +
                                "has a description attribute.",
                                pInfo[0].Name, mInfo.Name);
                            Console.WriteLine("The description is: \"{0}\"",
                                ((DescriptionAttribute)attr).Description);
                        }
                    }
                }
            }
        }
    }
}

/*
 * Output:
 * Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
 * Parameter args for method ParamArrayAndDesc has a description attribute.
 * The description is: "This argument is a ParamArray"
 */
open System
open System.Reflection
open System.ComponentModel

type AClass() =
    member _.ParamArrayAndDesc(
        // Add ParamArray and Description attributes.
        [<Description "This argument is a ParamArray">]
        [<ParamArray>]
        args: int[]) = ()

// Get the Class type to access its metadata.
let clsType = typeof<AClass>

// Get the type information for the method.
let mInfo = clsType.GetMethod "ParamArrayAndDesc"
if mInfo <> null then
    // Get the parameter information.
    let pInfo = mInfo.GetParameters()
    if pInfo <> null then
        // Iterate through all the attributes for the parameter.
        for attr in Attribute.GetCustomAttributes pInfo[0] do
            match attr with 
            // Check for the ParamArray attribute.
            | :? ParamArrayAttribute ->
                printfn $"Parameter {pInfo[0].Name} for method {mInfo.Name} has the ParamArray attribute."
                                
            // Check for the Description attribute.
            | :? DescriptionAttribute as attr ->
                printfn $"Parameter {pInfo[0].Name} for method {mInfo.Name} has a description attribute."
                printfn $"The description is: \"{attr.Description}\""
            | _ -> ()

// Output:
// Parameter args for method ParamArrayAndDesc has a description attribute.
// The description is: "This argument is a ParamArray"
// Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
Imports System.Reflection
Imports System.ComponentModel

Module DemoModule
    Public Class AClass
        ' Add Description and ParamArray (with the keyword) attributes.
        Public Sub ParamArrayAndDesc( _
            <Description("This argument is a ParamArray")> _
            ByVal ParamArray args() As Integer)
        End Sub
    End Class

    Sub Main()
        ' Get the Class type to access its metadata.
        Dim clsType As Type = GetType(AClass)
        ' Get the type information for the method.
        Dim mInfo As MethodInfo = clsType.GetMethod("ParamArrayAndDesc")
        ' Get the Parameter information for the method.
        Dim pInfo() As ParameterInfo = mInfo.GetParameters()
        Dim attr As Attribute
        ' Iterate through each attribute of the parameter.
        For Each attr In Attribute.GetCustomAttributes(pInfo(0))
            ' Check for the ParamArray attribute.
            If TypeOf attr Is ParamArrayAttribute Then
                ' Convert the attribute to access its data.
                Dim paAttr As ParamArrayAttribute = _
                    CType(attr, ParamArrayAttribute)
                Console.WriteLine("Parameter {0} for method {1} has the " + _
                    "ParamArray attribute.", pInfo(0).Name, mInfo.Name)
            ' Check for the Description attribute.
            ElseIf TypeOf attr Is DescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim descAttr As DescriptionAttribute = _
                    CType(attr, DescriptionAttribute)
                Console.WriteLine("Parameter {0} for method {1} has a description " + _
                    "attribute. The description is:", pInfo(0).Name, mInfo.Name)
                Console.WriteLine(descAttr.Description)
            End If
        Next
    End Sub
End Module

' Output:
' Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
' Parameter args for method ParamArrayAndDesc has a description attribute. The description is:
' This argument is a ParamArray

Observações

Se element representa um parâmetro num método de um tipo derivado, o valor de retorno inclui os atributos personalizados herdáveis aplicados ao mesmo parâmetro nos métodos base sobrepostos.

Aplica-se a

GetCustomAttributes(Module, Type, Boolean)

Recupera um array dos atributos personalizados aplicados a um módulo. Os parâmetros especificam o módulo, o tipo do atributo personalizado a procurar e uma opção de pesquisa ignorada.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::Module ^ element, Type ^ attributeType, bool inherit);
public static Attribute[] GetCustomAttributes(System.Reflection.Module element, Type attributeType, bool inherit);
static member GetCustomAttributes : System.Reflection.Module * Type * bool -> Attribute[]
Public Shared Function GetCustomAttributes (element As Module, attributeType As Type, inherit As Boolean) As Attribute()

Parâmetros

element
Module

Um objeto derivado da Module classe que descreve um ficheiro executável portátil.

attributeType
Type

O tipo, ou um tipo base, do atributo personalizado a procurar.

inherit
Boolean

Este parâmetro é ignorado e não afeta o funcionamento deste método.

Devoluções

Um array que contém os atributos personalizados do tipo attributeType aplicados a element, ou um array vazio se não existirem Attribute tais atributos personalizados.

Exceções

element ou attributeType é null.

attributeType não deriva de Attribute.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando a Module como parâmetro.

using System;
using System.Reflection;
using System.ComponentModel;

// Assign some attributes to the module.
[module:Description("A sample description")]

// Set the module's CLSCompliant attribute to false
// The CLSCompliant attribute is applicable for /target:module.
[module:CLSCompliant(false)]

namespace CustAttrs2CS {
    class DemoClass {
        static void Main(string[] args) {
            Type clsType = typeof(DemoClass);
            // Get the Module type to access its metadata.
            Module module = clsType.Module;

            // Iterate through all the attributes for the module.
            foreach(Attribute attr in Attribute.GetCustomAttributes(module)) {
                // Check for the Description attribute.
                if (attr.GetType() == typeof(DescriptionAttribute))
                    Console.WriteLine("Module {0} has the description " +
                        "\"{1}\".", module.Name,
                        ((DescriptionAttribute)attr).Description);
                // Check for the CLSCompliant attribute.
                else if (attr.GetType() == typeof(CLSCompliantAttribute))
                    Console.WriteLine("Module {0} {1} CLSCompliant.",
                        module.Name,
                        ((CLSCompliantAttribute)attr).IsCompliant ?
                            "is" : "is not");
            }
        }
    }
}

/*
 * Output:
 * Module CustAttrs2CS.exe is not CLSCompliant.
 * Module CustAttrs2CS.exe has the description "A sample description".
 */
open System
open System.ComponentModel

// Assign some attributes to the module.
[<``module``: Description "A sample description">]

// Set the module's CLSCompliant attribute to false
// The CLSCompliant attribute is applicable for /target:module.
[<``module``: CLSCompliant false>]
do ()

type DemoClass = class end

// Get the Module type to access its metadata.
let ilmodule = typeof<DemoClass>.Module

// Iterate through all the attributes for the module.
for attr in Attribute.GetCustomAttributes ilmodule do
    match attr with
    // Check for the Description attribute.
    | :? DescriptionAttribute as attr ->
        printfn $"Module {ilmodule.Name} has the description \"{attr.Description}\"."
                
    // Check for the CLSCompliant attribute.
    | :? CLSCompliantAttribute as attr ->
        printfn $"""Module {ilmodule.Name} {if attr.IsCompliant then "is" else "is not"} CLSCompliant."""
    | _ -> ()
    
// Output:
// Module CustAttrs2CS.exe is not CLSCompliant.
// Module CustAttrs2CS.exe has the description "A sample description".
Imports System.Reflection
Imports System.ComponentModel

' Give the Module some attributes.
<Module: Description("A sample description")> 

' Make the CLSCompliant attribute False.
' The CLSCompliant attribute is applicable for /target:module.
<Module: CLSCompliant(False)> 

Module DemoModule

    Sub Main()
        ' Get the Module type to access its metadata.
        Dim modType As Reflection.Module = GetType(DemoModule).Module
        Dim attr As Attribute
        ' Iterate through all the attributes for the module.
        For Each attr In Attribute.GetCustomAttributes(modType)
            ' Check for the Description attribute.
            If TypeOf attr Is DescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim descAttr As DescriptionAttribute = _
                    CType(attr, DescriptionAttribute)
                Console.WriteLine("Module {0} has the description ""{1}"".", _
                    modType.Name, descAttr.Description)

            ' Check for the CLSCompliant attribute.
            ElseIf TypeOf attr Is CLSCompliantAttribute Then
                ' Convert the attribute to access its data.
                Dim CLSCompAttr As CLSCompliantAttribute = _
                    CType(attr, CLSCompliantAttribute)
                Dim strCompliant As String
                If CLSCompAttr.IsCompliant Then
                    strCompliant = "is"
                Else
                    strCompliant = "is not"
                End If
                Console.WriteLine("Module {0} {1} CLSCompliant.", _
                    modType.Name, strCompliant)
            End If
        Next
    End Sub
End Module

' Output:
' Module CustAttrs2VB.exe has the description "A sample description".
' Module CustAttrs2VB.exe is not CLSCompliant.

Observações

O valor de retorno contém os atributos personalizados para os antepassados de element se inherit for true.

Aplica-se a

GetCustomAttributes(MemberInfo, Type)

Recupera um array dos atributos personalizados aplicados a um membro de um tipo. Os parâmetros especificam o membro e o tipo do atributo personalizado a procurar.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::MemberInfo ^ element, Type ^ type);
public static Attribute[] GetCustomAttributes(System.Reflection.MemberInfo element, Type type);
static member GetCustomAttributes : System.Reflection.MemberInfo * Type -> Attribute[]
Public Shared Function GetCustomAttributes (element As MemberInfo, type As Type) As Attribute()

Parâmetros

element
MemberInfo

Um objeto derivado da MemberInfo classe que descreve um construtor, evento, corpo, método ou propriedade membro de uma classe.

typeattributeType
Type

O tipo, ou um tipo base, do atributo personalizado a procurar.

Devoluções

Um array que contém os atributos personalizados do tipo type aplicados a element, ou um array vazio se não existirem Attribute tais atributos personalizados.

Exceções

element ou type é null.

type não deriva de Attribute.

element não é um construtor, método, propriedade, evento, tipo ou campo.

Um tipo de atributo personalizado não pode ser carregado.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttribute, tomando a MemberInfo como parâmetro.

using System;
using System.Reflection;
using System.Security;
using System.Runtime.InteropServices;

namespace CustAttrs4CS
{

    // Define an enumeration of Win32 unmanaged types
    public enum UnmanagedType
    {
        User,
        GDI,
        Kernel,
        Shell,
        Networking,
        Multimedia
    }

    // Define the Unmanaged attribute.
    public class UnmanagedAttribute : Attribute
    {
        // Storage for the UnmanagedType value.
        protected UnmanagedType thisType;

        // Set the unmanaged type in the constructor.
        public UnmanagedAttribute(UnmanagedType type)
        {
            thisType = type;
        }

        // Define a property to get and set the UnmanagedType value.
        public UnmanagedType Win32Type
        {
            get { return thisType; }
            set { thisType = Win32Type; }
        }
    }

    // Create a class for an imported Win32 unmanaged function.
    public class Win32 {
        [DllImport("user32.dll", CharSet = CharSet.Unicode)]
        public static extern int MessageBox(int hWnd, String text,
            String caption, uint type);
    }

    public class AClass {
        // Add some attributes to Win32CallMethod.
        [Obsolete("This method is obsolete. Use managed MsgBox instead.")]
        [Unmanaged(UnmanagedType.User)]
        public void Win32CallMethod()
        {
            Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0);
        }
    }

    class DemoClass {
        static void Main(string[] args)
            {
            // Get the AClass type to access its metadata.
            Type clsType = typeof(AClass);
            // Get the type information for Win32CallMethod.
            MethodInfo mInfo = clsType.GetMethod("Win32CallMethod");
            if (mInfo != null)
            {
                // Iterate through all the attributes of the method.
                foreach(Attribute attr in
                    Attribute.GetCustomAttributes(mInfo)) {
                    // Check for the Obsolete attribute.
                    if (attr.GetType() == typeof(ObsoleteAttribute))
                    {
                        Console.WriteLine("Method {0} is obsolete. " +
                            "The message is:",
                            mInfo.Name);
                        Console.WriteLine("  \"{0}\"",
                            ((ObsoleteAttribute)attr).Message);
                    }

                    // Check for the Unmanaged attribute.
                    else if (attr.GetType() == typeof(UnmanagedAttribute))
                    {
                        Console.WriteLine(
                            "This method calls unmanaged code.");
                        Console.WriteLine(
                            String.Format("The Unmanaged attribute type is {0}.",
                                          ((UnmanagedAttribute)attr).Win32Type));
                        AClass myCls = new AClass();
                        myCls.Win32CallMethod();
                    }
                }
            }
        }
    }
}

/*

This code example produces the following results.

First, the compilation yields the warning, "... This method is
obsolete. Use managed MsgBox instead."
Second, execution yields a message box with a title of "Caution!"
and message text of "This is an unmanaged call."
Third, the following text is displayed in the console window:

Method Win32CallMethod is obsolete. The message is:
  "This method is obsolete. Use managed MsgBox instead."
This method calls unmanaged code.
The Unmanaged attribute type is User.

*/
open System
open System.Runtime.InteropServices

// Define an enumeration of Win32 unmanaged types
type UnmanagedType =
    | User = 0
    | GDI = 1
    | Kernel = 2
    | Shell = 3
    | Networking = 4
    | Multimedia = 5

// Define the Unmanaged attribute.
type UnmanagedAttribute(unmanagedType) =
    inherit Attribute()
    
    // Define a property to get and set the UnmanagedType value.
    member val Win32Type = unmanagedType with get, set

// Create a module for an imported Win32 unmanaged function.
module Win32 =
    [<DllImport("user32.dll", CharSet = CharSet.Unicode)>]
    extern int MessageBox(IntPtr hWnd, String text, String caption, uint ``type``)

type AClass() =
    // Add some attributes to Win32CallMethod.
    [<Obsolete "This method is obsolete. Use managed MsgBox instead.">]
    [<Unmanaged(UnmanagedType.User)>]
    member _.Win32CallMethod () =
        Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0u)

// Get the AClass type to access its metadata.
let clsType = typeof<AClass>
// Get the type information for Win32CallMethod.
let mInfo = clsType.GetMethod "Win32CallMethod"
if mInfo <> null then
    // Iterate through all the attributes of the method.
    for attr in Attribute.GetCustomAttributes mInfo do
        match attr with 
        // Check for the Obsolete attribute.
        | :? ObsoleteAttribute as attr ->
            printfn $"Method {mInfo.Name} is obsolete. The message is:"
            printfn $"  \"{attr.Message}\""

        // Check for the Unmanaged attribute.
        | :? UnmanagedAttribute as attr ->
            printfn "This method calls unmanaged code."
            printfn $"The Unmanaged attribute type is {attr.Win32Type}."
            let myCls = AClass()
            myCls.Win32CallMethod() |> ignore
        | _ -> ()

// This code example produces the following results.
//
// First, the compilation yields the warning, "... This method is
// obsolete. Use managed MsgBox instead."
// Second, execution yields a message box with a title of "Caution!"
// and message text of "This is an unmanaged call."
// Third, the following text is displayed in the console window:

// Method Win32CallMethod is obsolete. The message is:
//   "This method is obsolete. Use managed MsgBox instead."
// This method calls unmanaged code.
// The Unmanaged attribute type is User.
Imports System.Reflection
Imports System.Security
Imports System.Runtime.InteropServices

' Define an enumeration of Win32 unmanaged types
Public Enum UnmanagedType
    User
    GDI
    Kernel
    Shell
    Networking
    Multimedia
End Enum 'UnmanagedType

' Define the Unmanaged attribute.
Public Class UnmanagedAttribute 
             Inherits Attribute

    ' Storage for the UnmanagedType value.
    Protected thisType As UnmanagedType
    
    ' Set the unmanaged type in the constructor.
    Public Sub New(ByVal type As UnmanagedType) 
        thisType = type
    End Sub
    
    ' Define a property to get and set the UnmanagedType value.
    Public Property Win32Type() As UnmanagedType 
        Get
            Return thisType
        End Get
        Set
            thisType = Win32Type
        End Set
    End Property
End Class

' Create a class for an imported Win32 unmanaged function.
Public Class Win32
    <DllImport("user32.dll", CharSet:=CharSet.Unicode)> _
    Public Shared Function MessageBox(ByVal hWnd As Integer, _
                                      ByVal Text As String, _
                                      ByVal caption As String, _
                                      ByVal type As Integer) As Integer
    End Function 'MessageBox
End Class

Public Class AClass
    ' Add some attributes to Win32CallMethod.
    <Obsolete("This method is obsolete. Use managed MsgBox instead."), _
     Unmanaged(UnmanagedType.User)>  _
    Public Sub Win32CallMethod() 
        Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0)    
    End Sub
End Class

Class DemoClass
    Shared Sub Main(ByVal args() As String) 
        ' Get the AClass type to access its metadata.
        Dim clsType As Type = GetType(AClass)
        ' Get the type information for Win32CallMethod.
        Dim mInfo As MethodInfo = clsType.GetMethod("Win32CallMethod")
        If Not (mInfo Is Nothing) Then
            ' Iterate through all the attributes of the method.
            Dim attr As Attribute
            For Each attr In  Attribute.GetCustomAttributes(mInfo)
                ' Check for the Obsolete attribute.
                If attr.GetType().Equals(GetType(ObsoleteAttribute)) Then
                    Console.WriteLine("Method {0} is obsolete. The message is:", mInfo.Name)
                    Console.WriteLine("  ""{0}""", CType(attr, ObsoleteAttribute).Message)
                ' Check for the Unmanaged attribute.
                ElseIf attr.GetType().Equals(GetType(UnmanagedAttribute)) Then
                    Console.WriteLine("This method calls unmanaged code.")
                    Console.WriteLine( _
                            String.Format("The Unmanaged attribute type is {0}.", _
                            CType(attr, UnmanagedAttribute).Win32Type))
                    Dim myCls As New AClass()
                    myCls.Win32CallMethod()
                End If
            Next attr
        End If
    End Sub
End Class

'
'This code example produces the following results. 
'
'First, the compilation yields the warning, "... This method is 
'obsolete. Use managed MsgBox instead."
'Second, execution yields a message box with a title of "Caution!" 
'and message text of "This is an unmanaged call." 
'Third, the following text is displayed in the console window:
'
'Method Win32CallMethod is obsolete. The message is:
'  "This method is obsolete. Use managed MsgBox instead."
'This method calls unmanaged code.
'The Unmanaged attribute type is User.
'

Observações

O valor de retorno contém os atributos personalizados para os antepassados de element.

Note

A partir do .NET Framework versão 2.0, este método devolve atributos de segurança nos métodos, construtores e tipos se os atributos estiverem armazenados no novo formato de metadados. Assemblies compilados com a versão 2.0 ou posterior utilizam o novo formato. Assemblies dinâmicos e assemblies compilados com versões anteriores do .NET Framework utilizam o antigo formato XML. Ver Emissão de Atributos de Segurança Declarativa.

Aplica-se a

GetCustomAttributes(Assembly, Type, Boolean)

Recupera um array dos atributos personalizados aplicados a uma assembleia. Os parâmetros especificam a montagem, o tipo do atributo personalizado a procurar e uma opção de pesquisa ignorada.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::Assembly ^ element, Type ^ attributeType, bool inherit);
public static Attribute[] GetCustomAttributes(System.Reflection.Assembly element, Type attributeType, bool inherit);
static member GetCustomAttributes : System.Reflection.Assembly * Type * bool -> Attribute[]
Public Shared Function GetCustomAttributes (element As Assembly, attributeType As Type, inherit As Boolean) As Attribute()

Parâmetros

element
Assembly

Um objeto derivado da Assembly classe que descreve uma coleção reutilizável de módulos.

attributeType
Type

O tipo, ou um tipo base, do atributo personalizado a procurar.

inherit
Boolean

Este parâmetro é ignorado e não afeta o funcionamento deste método.

Devoluções

Um array que contém os atributos personalizados do tipo attributeType aplicados a element, ou um array vazio se não existirem Attribute tais atributos personalizados.

Exceções

element ou attributeType é null.

attributeType não deriva de Attribute.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando um Assembly como parâmetro.

using System;
using System.Reflection;

[assembly: AssemblyTitle("CustAttrs1CS")]
[assembly: AssemblyDescription("GetCustomAttributes() Demo")]
[assembly: AssemblyCompany("Microsoft")]

class Example {
    static void Main() {
        // Get the Assembly object to access its metadata.
        Assembly assy = typeof(Example).Assembly;

        // Iterate through the attributes for the assembly.
        foreach(Attribute attr in Attribute.GetCustomAttributes(assy)) {
            // Check for the AssemblyTitle attribute.
            if (attr.GetType() == typeof(AssemblyTitleAttribute))
                Console.WriteLine("Assembly title is \"{0}\".",
                    ((AssemblyTitleAttribute)attr).Title);

            // Check for the AssemblyDescription attribute.
            else if (attr.GetType() ==
                typeof(AssemblyDescriptionAttribute))
                Console.WriteLine("Assembly description is \"{0}\".",
                    ((AssemblyDescriptionAttribute)attr).Description);

            // Check for the AssemblyCompany attribute.
            else if (attr.GetType() == typeof(AssemblyCompanyAttribute))
                Console.WriteLine("Assembly company is {0}.",
                    ((AssemblyCompanyAttribute)attr).Company);
        }
   }
}
// The example displays the following output:
//     Assembly title is "CustAttrs1CS".
//     Assembly description is "GetCustomAttributes() Demo".
//     Assembly company is Microsoft.
open System
open System.Reflection

[<assembly: AssemblyTitle "CustAttrs1CS">]
[<assembly: AssemblyDescription "GetCustomAttributes() Demo">]
[<assembly: AssemblyCompany"Microsoft">]
do ()

type Example = class end

// Get the Assembly object to access its metadata.
let assembly = typeof<Example>.Assembly

// Iterate through the attributes for the assembly.
for attr in Attribute.GetCustomAttributes assembly do
    match attr with
    // Check for the AssemblyTitle attribute.
    | :? AssemblyTitleAttribute as attr ->    
        printfn $"Assembly title is \"{attr.Title}\"."
    // Check for the AssemblyDescription attribute.
    | :? AssemblyDescriptionAttribute as attr ->
        printfn $"Assembly description is \"{attr.Description}\"."
    // Check for the AssemblyCompany attribute.
    | :? AssemblyCompanyAttribute as attr ->
        printfn $"Assembly company is {attr.Company}."
    | _ -> ()
    
// The example displays the following output:
//     Assembly title is "CustAttrs1CS".
//     Assembly description is "GetCustomAttributes() Demo".
//     Assembly company is Microsoft.
Imports System.Reflection

<Assembly: AssemblyTitle("CustAttrs1VB")> 
<Assembly: AssemblyDescription("GetCustomAttributes() Demo")> 
<Assembly: AssemblyCompany("Microsoft")> 

Module Example
    Sub Main()
        ' Get the Assembly type to access its metadata.
        Dim assy As Reflection.Assembly = GetType(Example).Assembly

        ' Iterate through all the attributes for the assembly.
        For Each attr As Attribute In Attribute.GetCustomAttributes(assy)
            ' Check for the AssemblyTitle attribute.
            If TypeOf attr Is AssemblyTitleAttribute Then
                ' Convert the attribute to access its data.
                Dim attrTitle As AssemblyTitleAttribute = _
                    CType(attr, AssemblyTitleAttribute)
                Console.WriteLine("Assembly title is ""{0}"".", _
                    attrTitle.Title)

            ' Check for the AssemblyDescription attribute.
            ElseIf TypeOf attr Is AssemblyDescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim attrDesc As AssemblyDescriptionAttribute = _
                    CType(attr, AssemblyDescriptionAttribute)
                Console.WriteLine("Assembly description is ""{0}"".", _
                    attrDesc.Description)

            ' Check for the AssemblyCompany attribute.
            ElseIf TypeOf attr Is AssemblyCompanyAttribute Then
                ' Convert the attribute to access its data.
                Dim attrComp As AssemblyCompanyAttribute = _
                    CType(attr, AssemblyCompanyAttribute)
                Console.WriteLine("Assembly company is {0}.", _
                    attrComp.Company)
            End If
        Next
    End Sub
End Module
' The example displays the following output:
'     Assembly company is Microsoft.
'     Assembly description is "GetCustomAttributes() Demo".
'     Assembly title is "CustAttrs1VB".

Observações

Note

A partir da versão 2.0 do .NET Framework, este método devolve atributos de segurança se os atributos estiverem armazenados no novo formato de metadados. Assemblies compilados com a versão 2.0 ou posterior utilizam o novo formato. Assemblies dinâmicos e assemblies compilados com versões anteriores do .NET Framework utilizam o antigo formato XML. Ver Emissão de Atributos de Segurança Declarativa.

Aplica-se a

GetCustomAttributes(Module, Type)

Recupera um array dos atributos personalizados aplicados a um módulo. Os parâmetros especificam o módulo e o tipo do atributo personalizado a procurar.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::Module ^ element, Type ^ attributeType);
public static Attribute[] GetCustomAttributes(System.Reflection.Module element, Type attributeType);
static member GetCustomAttributes : System.Reflection.Module * Type -> Attribute[]
Public Shared Function GetCustomAttributes (element As Module, attributeType As Type) As Attribute()

Parâmetros

element
Module

Um objeto derivado da Module classe que descreve um ficheiro executável portátil.

attributeType
Type

O tipo, ou um tipo base, do atributo personalizado a procurar.

Devoluções

Um array que contém os atributos personalizados do tipo attributeType aplicados a element, ou um array vazio se não existirem Attribute tais atributos personalizados.

Exceções

element ou attributeType é null.

attributeType não deriva de Attribute.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando a Module como parâmetro.

using System;
using System.Reflection;
using System.ComponentModel;

// Assign some attributes to the module.
[module:Description("A sample description")]

// Set the module's CLSCompliant attribute to false
// The CLSCompliant attribute is applicable for /target:module.
[module:CLSCompliant(false)]

namespace CustAttrs2CS {
    class DemoClass {
        static void Main(string[] args) {
            Type clsType = typeof(DemoClass);
            // Get the Module type to access its metadata.
            Module module = clsType.Module;

            // Iterate through all the attributes for the module.
            foreach(Attribute attr in Attribute.GetCustomAttributes(module)) {
                // Check for the Description attribute.
                if (attr.GetType() == typeof(DescriptionAttribute))
                    Console.WriteLine("Module {0} has the description " +
                        "\"{1}\".", module.Name,
                        ((DescriptionAttribute)attr).Description);
                // Check for the CLSCompliant attribute.
                else if (attr.GetType() == typeof(CLSCompliantAttribute))
                    Console.WriteLine("Module {0} {1} CLSCompliant.",
                        module.Name,
                        ((CLSCompliantAttribute)attr).IsCompliant ?
                            "is" : "is not");
            }
        }
    }
}

/*
 * Output:
 * Module CustAttrs2CS.exe is not CLSCompliant.
 * Module CustAttrs2CS.exe has the description "A sample description".
 */
open System
open System.ComponentModel

// Assign some attributes to the module.
[<``module``: Description "A sample description">]

// Set the module's CLSCompliant attribute to false
// The CLSCompliant attribute is applicable for /target:module.
[<``module``: CLSCompliant false>]
do ()

type DemoClass = class end

// Get the Module type to access its metadata.
let ilmodule = typeof<DemoClass>.Module

// Iterate through all the attributes for the module.
for attr in Attribute.GetCustomAttributes ilmodule do
    match attr with
    // Check for the Description attribute.
    | :? DescriptionAttribute as attr ->
        printfn $"Module {ilmodule.Name} has the description \"{attr.Description}\"."
                
    // Check for the CLSCompliant attribute.
    | :? CLSCompliantAttribute as attr ->
        printfn $"""Module {ilmodule.Name} {if attr.IsCompliant then "is" else "is not"} CLSCompliant."""
    | _ -> ()
    
// Output:
// Module CustAttrs2CS.exe is not CLSCompliant.
// Module CustAttrs2CS.exe has the description "A sample description".
Imports System.Reflection
Imports System.ComponentModel

' Give the Module some attributes.
<Module: Description("A sample description")> 

' Make the CLSCompliant attribute False.
' The CLSCompliant attribute is applicable for /target:module.
<Module: CLSCompliant(False)> 

Module DemoModule

    Sub Main()
        ' Get the Module type to access its metadata.
        Dim modType As Reflection.Module = GetType(DemoModule).Module
        Dim attr As Attribute
        ' Iterate through all the attributes for the module.
        For Each attr In Attribute.GetCustomAttributes(modType)
            ' Check for the Description attribute.
            If TypeOf attr Is DescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim descAttr As DescriptionAttribute = _
                    CType(attr, DescriptionAttribute)
                Console.WriteLine("Module {0} has the description ""{1}"".", _
                    modType.Name, descAttr.Description)

            ' Check for the CLSCompliant attribute.
            ElseIf TypeOf attr Is CLSCompliantAttribute Then
                ' Convert the attribute to access its data.
                Dim CLSCompAttr As CLSCompliantAttribute = _
                    CType(attr, CLSCompliantAttribute)
                Dim strCompliant As String
                If CLSCompAttr.IsCompliant Then
                    strCompliant = "is"
                Else
                    strCompliant = "is not"
                End If
                Console.WriteLine("Module {0} {1} CLSCompliant.", _
                    modType.Name, strCompliant)
            End If
        Next
    End Sub
End Module

' Output:
' Module CustAttrs2VB.exe has the description "A sample description".
' Module CustAttrs2VB.exe is not CLSCompliant.

Aplica-se a

GetCustomAttributes(ParameterInfo, Type)

Recupera um array dos atributos personalizados aplicados a um parâmetro de método. Os parâmetros especificam o parâmetro do método e o tipo do atributo personalizado a procurar.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::ParameterInfo ^ element, Type ^ attributeType);
public static Attribute[] GetCustomAttributes(System.Reflection.ParameterInfo element, Type attributeType);
static member GetCustomAttributes : System.Reflection.ParameterInfo * Type -> Attribute[]
Public Shared Function GetCustomAttributes (element As ParameterInfo, attributeType As Type) As Attribute()

Parâmetros

element
ParameterInfo

Um objeto derivado da ParameterInfo classe que descreve um parâmetro de um membro de uma classe.

attributeType
Type

O tipo, ou um tipo base, do atributo personalizado a procurar.

Devoluções

Um array que contém os atributos personalizados do tipo attributeType aplicados a element, ou um array vazio se não existirem Attribute tais atributos personalizados.

Exceções

element ou attributeType é null.

attributeType não deriva de Attribute.

Um tipo de atributo personalizado não pode ser carregado.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando a ParameterInfo como parâmetro.

using System;
using System.Reflection;
using System.ComponentModel;

namespace CustAttrs5CS {
    public class AClass {
        public void ParamArrayAndDesc(
            // Add ParamArray (with the keyword) and Description attributes.
            [Description("This argument is a ParamArray")]
            params int[] args)
        {}
    }

    class DemoClass {
        static void Main(string[] args) {
            // Get the Class type to access its metadata.
            Type clsType = typeof(AClass);
            // Get the type information for the method.
            MethodInfo mInfo = clsType.GetMethod("ParamArrayAndDesc");
            if (mInfo != null) {
                // Get the parameter information.
                ParameterInfo[] pInfo = mInfo.GetParameters();
                if (pInfo != null) {
                    // Iterate through all the attributes for the parameter.
                    foreach(Attribute attr in
                        Attribute.GetCustomAttributes(pInfo[0])) {
                        // Check for the ParamArray attribute.
                        if (attr.GetType() == typeof(ParamArrayAttribute))
                            Console.WriteLine("Parameter {0} for method {1} " +
                                "has the ParamArray attribute.",
                                pInfo[0].Name, mInfo.Name);
                        // Check for the Description attribute.
                        else if (attr.GetType() ==
                            typeof(DescriptionAttribute)) {
                            Console.WriteLine("Parameter {0} for method {1} " +
                                "has a description attribute.",
                                pInfo[0].Name, mInfo.Name);
                            Console.WriteLine("The description is: \"{0}\"",
                                ((DescriptionAttribute)attr).Description);
                        }
                    }
                }
            }
        }
    }
}

/*
 * Output:
 * Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
 * Parameter args for method ParamArrayAndDesc has a description attribute.
 * The description is: "This argument is a ParamArray"
 */
open System
open System.Reflection
open System.ComponentModel

type AClass() =
    member _.ParamArrayAndDesc(
        // Add ParamArray and Description attributes.
        [<Description "This argument is a ParamArray">]
        [<ParamArray>]
        args: int[]) = ()

// Get the Class type to access its metadata.
let clsType = typeof<AClass>

// Get the type information for the method.
let mInfo = clsType.GetMethod "ParamArrayAndDesc"
if mInfo <> null then
    // Get the parameter information.
    let pInfo = mInfo.GetParameters()
    if pInfo <> null then
        // Iterate through all the attributes for the parameter.
        for attr in Attribute.GetCustomAttributes pInfo[0] do
            match attr with 
            // Check for the ParamArray attribute.
            | :? ParamArrayAttribute ->
                printfn $"Parameter {pInfo[0].Name} for method {mInfo.Name} has the ParamArray attribute."
                                
            // Check for the Description attribute.
            | :? DescriptionAttribute as attr ->
                printfn $"Parameter {pInfo[0].Name} for method {mInfo.Name} has a description attribute."
                printfn $"The description is: \"{attr.Description}\""
            | _ -> ()

// Output:
// Parameter args for method ParamArrayAndDesc has a description attribute.
// The description is: "This argument is a ParamArray"
// Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
Imports System.Reflection
Imports System.ComponentModel

Module DemoModule
    Public Class AClass
        ' Add Description and ParamArray (with the keyword) attributes.
        Public Sub ParamArrayAndDesc( _
            <Description("This argument is a ParamArray")> _
            ByVal ParamArray args() As Integer)
        End Sub
    End Class

    Sub Main()
        ' Get the Class type to access its metadata.
        Dim clsType As Type = GetType(AClass)
        ' Get the type information for the method.
        Dim mInfo As MethodInfo = clsType.GetMethod("ParamArrayAndDesc")
        ' Get the Parameter information for the method.
        Dim pInfo() As ParameterInfo = mInfo.GetParameters()
        Dim attr As Attribute
        ' Iterate through each attribute of the parameter.
        For Each attr In Attribute.GetCustomAttributes(pInfo(0))
            ' Check for the ParamArray attribute.
            If TypeOf attr Is ParamArrayAttribute Then
                ' Convert the attribute to access its data.
                Dim paAttr As ParamArrayAttribute = _
                    CType(attr, ParamArrayAttribute)
                Console.WriteLine("Parameter {0} for method {1} has the " + _
                    "ParamArray attribute.", pInfo(0).Name, mInfo.Name)
            ' Check for the Description attribute.
            ElseIf TypeOf attr Is DescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim descAttr As DescriptionAttribute = _
                    CType(attr, DescriptionAttribute)
                Console.WriteLine("Parameter {0} for method {1} has a description " + _
                    "attribute. The description is:", pInfo(0).Name, mInfo.Name)
                Console.WriteLine(descAttr.Description)
            End If
        Next
    End Sub
End Module

' Output:
' Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
' Parameter args for method ParamArrayAndDesc has a description attribute. The description is:
' This argument is a ParamArray

Observações

Se element representa um parâmetro num método de um tipo derivado, o valor de retorno inclui os atributos personalizados herdáveis aplicados ao mesmo parâmetro nos métodos base sobrepostos.

Aplica-se a

GetCustomAttributes(MemberInfo, Boolean)

Recupera um array dos atributos personalizados aplicados a um membro de um tipo. Os parâmetros especificam o membro, o tipo do atributo personalizado a procurar e se deve procurar antepassados do membro.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::MemberInfo ^ element, bool inherit);
public static Attribute[] GetCustomAttributes(System.Reflection.MemberInfo element, bool inherit);
static member GetCustomAttributes : System.Reflection.MemberInfo * bool -> Attribute[]
Public Shared Function GetCustomAttributes (element As MemberInfo, inherit As Boolean) As Attribute()

Parâmetros

element
MemberInfo

Um objeto derivado da MemberInfo classe que descreve um construtor, evento, corpo, método ou propriedade membro de uma classe.

inherit
Boolean

Se true, especifica também procurar os antepassados de element por atributos personalizados.

Devoluções

Um Attribute array que contenha os atributos personalizados aplicados a element, ou um array vazio se não existirem tais atributos personalizados.

Exceções

element é null.

element não é um construtor, método, propriedade, evento, tipo ou campo.

Um tipo de atributo personalizado não pode ser carregado.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando a MemberInfo como parâmetro.

using System;
using System.Reflection;
using System.Security;
using System.Runtime.InteropServices;

namespace CustAttrs4CS
{

    // Define an enumeration of Win32 unmanaged types
    public enum UnmanagedType
    {
        User,
        GDI,
        Kernel,
        Shell,
        Networking,
        Multimedia
    }

    // Define the Unmanaged attribute.
    public class UnmanagedAttribute : Attribute
    {
        // Storage for the UnmanagedType value.
        protected UnmanagedType thisType;

        // Set the unmanaged type in the constructor.
        public UnmanagedAttribute(UnmanagedType type)
        {
            thisType = type;
        }

        // Define a property to get and set the UnmanagedType value.
        public UnmanagedType Win32Type
        {
            get { return thisType; }
            set { thisType = Win32Type; }
        }
    }

    // Create a class for an imported Win32 unmanaged function.
    public class Win32 {
        [DllImport("user32.dll", CharSet = CharSet.Unicode)]
        public static extern int MessageBox(int hWnd, String text,
            String caption, uint type);
    }

    public class AClass {
        // Add some attributes to Win32CallMethod.
        [Obsolete("This method is obsolete. Use managed MsgBox instead.")]
        [Unmanaged(UnmanagedType.User)]
        public void Win32CallMethod()
        {
            Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0);
        }
    }

    class DemoClass {
        static void Main(string[] args)
            {
            // Get the AClass type to access its metadata.
            Type clsType = typeof(AClass);
            // Get the type information for Win32CallMethod.
            MethodInfo mInfo = clsType.GetMethod("Win32CallMethod");
            if (mInfo != null)
            {
                // Iterate through all the attributes of the method.
                foreach(Attribute attr in
                    Attribute.GetCustomAttributes(mInfo)) {
                    // Check for the Obsolete attribute.
                    if (attr.GetType() == typeof(ObsoleteAttribute))
                    {
                        Console.WriteLine("Method {0} is obsolete. " +
                            "The message is:",
                            mInfo.Name);
                        Console.WriteLine("  \"{0}\"",
                            ((ObsoleteAttribute)attr).Message);
                    }

                    // Check for the Unmanaged attribute.
                    else if (attr.GetType() == typeof(UnmanagedAttribute))
                    {
                        Console.WriteLine(
                            "This method calls unmanaged code.");
                        Console.WriteLine(
                            String.Format("The Unmanaged attribute type is {0}.",
                                          ((UnmanagedAttribute)attr).Win32Type));
                        AClass myCls = new AClass();
                        myCls.Win32CallMethod();
                    }
                }
            }
        }
    }
}

/*

This code example produces the following results.

First, the compilation yields the warning, "... This method is
obsolete. Use managed MsgBox instead."
Second, execution yields a message box with a title of "Caution!"
and message text of "This is an unmanaged call."
Third, the following text is displayed in the console window:

Method Win32CallMethod is obsolete. The message is:
  "This method is obsolete. Use managed MsgBox instead."
This method calls unmanaged code.
The Unmanaged attribute type is User.

*/
open System
open System.Runtime.InteropServices

// Define an enumeration of Win32 unmanaged types
type UnmanagedType =
    | User = 0
    | GDI = 1
    | Kernel = 2
    | Shell = 3
    | Networking = 4
    | Multimedia = 5

// Define the Unmanaged attribute.
type UnmanagedAttribute(unmanagedType) =
    inherit Attribute()
    
    // Define a property to get and set the UnmanagedType value.
    member val Win32Type = unmanagedType with get, set

// Create a module for an imported Win32 unmanaged function.
module Win32 =
    [<DllImport("user32.dll", CharSet = CharSet.Unicode)>]
    extern int MessageBox(IntPtr hWnd, String text, String caption, uint ``type``)

type AClass() =
    // Add some attributes to Win32CallMethod.
    [<Obsolete "This method is obsolete. Use managed MsgBox instead.">]
    [<Unmanaged(UnmanagedType.User)>]
    member _.Win32CallMethod () =
        Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0u)

// Get the AClass type to access its metadata.
let clsType = typeof<AClass>
// Get the type information for Win32CallMethod.
let mInfo = clsType.GetMethod "Win32CallMethod"
if mInfo <> null then
    // Iterate through all the attributes of the method.
    for attr in Attribute.GetCustomAttributes mInfo do
        match attr with 
        // Check for the Obsolete attribute.
        | :? ObsoleteAttribute as attr ->
            printfn $"Method {mInfo.Name} is obsolete. The message is:"
            printfn $"  \"{attr.Message}\""

        // Check for the Unmanaged attribute.
        | :? UnmanagedAttribute as attr ->
            printfn "This method calls unmanaged code."
            printfn $"The Unmanaged attribute type is {attr.Win32Type}."
            let myCls = AClass()
            myCls.Win32CallMethod() |> ignore
        | _ -> ()

// This code example produces the following results.
//
// First, the compilation yields the warning, "... This method is
// obsolete. Use managed MsgBox instead."
// Second, execution yields a message box with a title of "Caution!"
// and message text of "This is an unmanaged call."
// Third, the following text is displayed in the console window:

// Method Win32CallMethod is obsolete. The message is:
//   "This method is obsolete. Use managed MsgBox instead."
// This method calls unmanaged code.
// The Unmanaged attribute type is User.
Imports System.Reflection
Imports System.Security
Imports System.Runtime.InteropServices

' Define an enumeration of Win32 unmanaged types
Public Enum UnmanagedType
    User
    GDI
    Kernel
    Shell
    Networking
    Multimedia
End Enum 'UnmanagedType

' Define the Unmanaged attribute.
Public Class UnmanagedAttribute 
             Inherits Attribute

    ' Storage for the UnmanagedType value.
    Protected thisType As UnmanagedType
    
    ' Set the unmanaged type in the constructor.
    Public Sub New(ByVal type As UnmanagedType) 
        thisType = type
    End Sub
    
    ' Define a property to get and set the UnmanagedType value.
    Public Property Win32Type() As UnmanagedType 
        Get
            Return thisType
        End Get
        Set
            thisType = Win32Type
        End Set
    End Property
End Class

' Create a class for an imported Win32 unmanaged function.
Public Class Win32
    <DllImport("user32.dll", CharSet:=CharSet.Unicode)> _
    Public Shared Function MessageBox(ByVal hWnd As Integer, _
                                      ByVal Text As String, _
                                      ByVal caption As String, _
                                      ByVal type As Integer) As Integer
    End Function 'MessageBox
End Class

Public Class AClass
    ' Add some attributes to Win32CallMethod.
    <Obsolete("This method is obsolete. Use managed MsgBox instead."), _
     Unmanaged(UnmanagedType.User)>  _
    Public Sub Win32CallMethod() 
        Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0)    
    End Sub
End Class

Class DemoClass
    Shared Sub Main(ByVal args() As String) 
        ' Get the AClass type to access its metadata.
        Dim clsType As Type = GetType(AClass)
        ' Get the type information for Win32CallMethod.
        Dim mInfo As MethodInfo = clsType.GetMethod("Win32CallMethod")
        If Not (mInfo Is Nothing) Then
            ' Iterate through all the attributes of the method.
            Dim attr As Attribute
            For Each attr In  Attribute.GetCustomAttributes(mInfo)
                ' Check for the Obsolete attribute.
                If attr.GetType().Equals(GetType(ObsoleteAttribute)) Then
                    Console.WriteLine("Method {0} is obsolete. The message is:", mInfo.Name)
                    Console.WriteLine("  ""{0}""", CType(attr, ObsoleteAttribute).Message)
                ' Check for the Unmanaged attribute.
                ElseIf attr.GetType().Equals(GetType(UnmanagedAttribute)) Then
                    Console.WriteLine("This method calls unmanaged code.")
                    Console.WriteLine( _
                            String.Format("The Unmanaged attribute type is {0}.", _
                            CType(attr, UnmanagedAttribute).Win32Type))
                    Dim myCls As New AClass()
                    myCls.Win32CallMethod()
                End If
            Next attr
        End If
    End Sub
End Class

'
'This code example produces the following results. 
'
'First, the compilation yields the warning, "... This method is 
'obsolete. Use managed MsgBox instead."
'Second, execution yields a message box with a title of "Caution!" 
'and message text of "This is an unmanaged call." 
'Third, the following text is displayed in the console window:
'
'Method Win32CallMethod is obsolete. The message is:
'  "This method is obsolete. Use managed MsgBox instead."
'This method calls unmanaged code.
'The Unmanaged attribute type is User.
'

Observações

O valor de retorno contém os atributos personalizados para os antepassados de element se inherit for true.

Note

A partir do .NET Framework versão 2.0, este método devolve atributos de segurança nos métodos, construtores e tipos se os atributos estiverem armazenados no novo formato de metadados. Assemblies compilados com a versão 2.0 ou posterior utilizam o novo formato. Assemblies dinâmicos e assemblies compilados com versões anteriores do .NET Framework utilizam o antigo formato XML. Ver Emissão de Atributos de Segurança Declarativa.

Aplica-se a

GetCustomAttributes(Assembly, Type)

Recupera um array dos atributos personalizados aplicados a uma assembleia. Os parâmetros especificam a montagem e o tipo do atributo personalizado a procurar.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::Assembly ^ element, Type ^ attributeType);
public static Attribute[] GetCustomAttributes(System.Reflection.Assembly element, Type attributeType);
static member GetCustomAttributes : System.Reflection.Assembly * Type -> Attribute[]
Public Shared Function GetCustomAttributes (element As Assembly, attributeType As Type) As Attribute()

Parâmetros

element
Assembly

Um objeto derivado da Assembly classe que descreve uma coleção reutilizável de módulos.

attributeType
Type

O tipo, ou um tipo base, do atributo personalizado a procurar.

Devoluções

Um array que contém os atributos personalizados do tipo attributeType aplicados a element, ou um array vazio se não existirem Attribute tais atributos personalizados.

Exceções

element ou attributeType é null.

attributeType não deriva de Attribute.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando um Assembly como parâmetro.

using System;
using System.Reflection;

[assembly: AssemblyTitle("CustAttrs1CS")]
[assembly: AssemblyDescription("GetCustomAttributes() Demo")]
[assembly: AssemblyCompany("Microsoft")]

class Example {
    static void Main() {
        // Get the Assembly object to access its metadata.
        Assembly assy = typeof(Example).Assembly;

        // Iterate through the attributes for the assembly.
        foreach(Attribute attr in Attribute.GetCustomAttributes(assy)) {
            // Check for the AssemblyTitle attribute.
            if (attr.GetType() == typeof(AssemblyTitleAttribute))
                Console.WriteLine("Assembly title is \"{0}\".",
                    ((AssemblyTitleAttribute)attr).Title);

            // Check for the AssemblyDescription attribute.
            else if (attr.GetType() ==
                typeof(AssemblyDescriptionAttribute))
                Console.WriteLine("Assembly description is \"{0}\".",
                    ((AssemblyDescriptionAttribute)attr).Description);

            // Check for the AssemblyCompany attribute.
            else if (attr.GetType() == typeof(AssemblyCompanyAttribute))
                Console.WriteLine("Assembly company is {0}.",
                    ((AssemblyCompanyAttribute)attr).Company);
        }
   }
}
// The example displays the following output:
//     Assembly title is "CustAttrs1CS".
//     Assembly description is "GetCustomAttributes() Demo".
//     Assembly company is Microsoft.
open System
open System.Reflection

[<assembly: AssemblyTitle "CustAttrs1CS">]
[<assembly: AssemblyDescription "GetCustomAttributes() Demo">]
[<assembly: AssemblyCompany"Microsoft">]
do ()

type Example = class end

// Get the Assembly object to access its metadata.
let assembly = typeof<Example>.Assembly

// Iterate through the attributes for the assembly.
for attr in Attribute.GetCustomAttributes assembly do
    match attr with
    // Check for the AssemblyTitle attribute.
    | :? AssemblyTitleAttribute as attr ->    
        printfn $"Assembly title is \"{attr.Title}\"."
    // Check for the AssemblyDescription attribute.
    | :? AssemblyDescriptionAttribute as attr ->
        printfn $"Assembly description is \"{attr.Description}\"."
    // Check for the AssemblyCompany attribute.
    | :? AssemblyCompanyAttribute as attr ->
        printfn $"Assembly company is {attr.Company}."
    | _ -> ()
    
// The example displays the following output:
//     Assembly title is "CustAttrs1CS".
//     Assembly description is "GetCustomAttributes() Demo".
//     Assembly company is Microsoft.
Imports System.Reflection

<Assembly: AssemblyTitle("CustAttrs1VB")> 
<Assembly: AssemblyDescription("GetCustomAttributes() Demo")> 
<Assembly: AssemblyCompany("Microsoft")> 

Module Example
    Sub Main()
        ' Get the Assembly type to access its metadata.
        Dim assy As Reflection.Assembly = GetType(Example).Assembly

        ' Iterate through all the attributes for the assembly.
        For Each attr As Attribute In Attribute.GetCustomAttributes(assy)
            ' Check for the AssemblyTitle attribute.
            If TypeOf attr Is AssemblyTitleAttribute Then
                ' Convert the attribute to access its data.
                Dim attrTitle As AssemblyTitleAttribute = _
                    CType(attr, AssemblyTitleAttribute)
                Console.WriteLine("Assembly title is ""{0}"".", _
                    attrTitle.Title)

            ' Check for the AssemblyDescription attribute.
            ElseIf TypeOf attr Is AssemblyDescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim attrDesc As AssemblyDescriptionAttribute = _
                    CType(attr, AssemblyDescriptionAttribute)
                Console.WriteLine("Assembly description is ""{0}"".", _
                    attrDesc.Description)

            ' Check for the AssemblyCompany attribute.
            ElseIf TypeOf attr Is AssemblyCompanyAttribute Then
                ' Convert the attribute to access its data.
                Dim attrComp As AssemblyCompanyAttribute = _
                    CType(attr, AssemblyCompanyAttribute)
                Console.WriteLine("Assembly company is {0}.", _
                    attrComp.Company)
            End If
        Next
    End Sub
End Module
' The example displays the following output:
'     Assembly company is Microsoft.
'     Assembly description is "GetCustomAttributes() Demo".
'     Assembly title is "CustAttrs1VB".

Observações

Note

A partir da versão 2.0 do .NET Framework, este método devolve atributos de segurança se os atributos estiverem armazenados no novo formato de metadados. Assemblies compilados com a versão 2.0 ou posterior utilizam o novo formato. Assemblies dinâmicos e assemblies compilados com versões anteriores do .NET Framework utilizam o antigo formato XML. Ver Emissão de Atributos de Segurança Declarativa.

Aplica-se a

GetCustomAttributes(Assembly, Boolean)

Recupera um array dos atributos personalizados aplicados a uma assembleia. Os parâmetros especificam a montagem e uma opção de pesquisa ignorada.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::Assembly ^ element, bool inherit);
public static Attribute[] GetCustomAttributes(System.Reflection.Assembly element, bool inherit);
static member GetCustomAttributes : System.Reflection.Assembly * bool -> Attribute[]
Public Shared Function GetCustomAttributes (element As Assembly, inherit As Boolean) As Attribute()

Parâmetros

element
Assembly

Um objeto derivado da Assembly classe que descreve uma coleção reutilizável de módulos.

inherit
Boolean

Este parâmetro é ignorado e não afeta o funcionamento deste método.

Devoluções

Um Attribute array que contenha os atributos personalizados aplicados a element, ou um array vazio se não existirem tais atributos personalizados.

Exceções

element é null.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando um Assembly como parâmetro.

using System;
using System.Reflection;

[assembly: AssemblyTitle("CustAttrs1CS")]
[assembly: AssemblyDescription("GetCustomAttributes() Demo")]
[assembly: AssemblyCompany("Microsoft")]

class Example {
    static void Main() {
        // Get the Assembly object to access its metadata.
        Assembly assy = typeof(Example).Assembly;

        // Iterate through the attributes for the assembly.
        foreach(Attribute attr in Attribute.GetCustomAttributes(assy)) {
            // Check for the AssemblyTitle attribute.
            if (attr.GetType() == typeof(AssemblyTitleAttribute))
                Console.WriteLine("Assembly title is \"{0}\".",
                    ((AssemblyTitleAttribute)attr).Title);

            // Check for the AssemblyDescription attribute.
            else if (attr.GetType() ==
                typeof(AssemblyDescriptionAttribute))
                Console.WriteLine("Assembly description is \"{0}\".",
                    ((AssemblyDescriptionAttribute)attr).Description);

            // Check for the AssemblyCompany attribute.
            else if (attr.GetType() == typeof(AssemblyCompanyAttribute))
                Console.WriteLine("Assembly company is {0}.",
                    ((AssemblyCompanyAttribute)attr).Company);
        }
   }
}
// The example displays the following output:
//     Assembly title is "CustAttrs1CS".
//     Assembly description is "GetCustomAttributes() Demo".
//     Assembly company is Microsoft.
open System
open System.Reflection

[<assembly: AssemblyTitle "CustAttrs1CS">]
[<assembly: AssemblyDescription "GetCustomAttributes() Demo">]
[<assembly: AssemblyCompany"Microsoft">]
do ()

type Example = class end

// Get the Assembly object to access its metadata.
let assembly = typeof<Example>.Assembly

// Iterate through the attributes for the assembly.
for attr in Attribute.GetCustomAttributes assembly do
    match attr with
    // Check for the AssemblyTitle attribute.
    | :? AssemblyTitleAttribute as attr ->    
        printfn $"Assembly title is \"{attr.Title}\"."
    // Check for the AssemblyDescription attribute.
    | :? AssemblyDescriptionAttribute as attr ->
        printfn $"Assembly description is \"{attr.Description}\"."
    // Check for the AssemblyCompany attribute.
    | :? AssemblyCompanyAttribute as attr ->
        printfn $"Assembly company is {attr.Company}."
    | _ -> ()
    
// The example displays the following output:
//     Assembly title is "CustAttrs1CS".
//     Assembly description is "GetCustomAttributes() Demo".
//     Assembly company is Microsoft.
Imports System.Reflection

<Assembly: AssemblyTitle("CustAttrs1VB")> 
<Assembly: AssemblyDescription("GetCustomAttributes() Demo")> 
<Assembly: AssemblyCompany("Microsoft")> 

Module Example
    Sub Main()
        ' Get the Assembly type to access its metadata.
        Dim assy As Reflection.Assembly = GetType(Example).Assembly

        ' Iterate through all the attributes for the assembly.
        For Each attr As Attribute In Attribute.GetCustomAttributes(assy)
            ' Check for the AssemblyTitle attribute.
            If TypeOf attr Is AssemblyTitleAttribute Then
                ' Convert the attribute to access its data.
                Dim attrTitle As AssemblyTitleAttribute = _
                    CType(attr, AssemblyTitleAttribute)
                Console.WriteLine("Assembly title is ""{0}"".", _
                    attrTitle.Title)

            ' Check for the AssemblyDescription attribute.
            ElseIf TypeOf attr Is AssemblyDescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim attrDesc As AssemblyDescriptionAttribute = _
                    CType(attr, AssemblyDescriptionAttribute)
                Console.WriteLine("Assembly description is ""{0}"".", _
                    attrDesc.Description)

            ' Check for the AssemblyCompany attribute.
            ElseIf TypeOf attr Is AssemblyCompanyAttribute Then
                ' Convert the attribute to access its data.
                Dim attrComp As AssemblyCompanyAttribute = _
                    CType(attr, AssemblyCompanyAttribute)
                Console.WriteLine("Assembly company is {0}.", _
                    attrComp.Company)
            End If
        Next
    End Sub
End Module
' The example displays the following output:
'     Assembly company is Microsoft.
'     Assembly description is "GetCustomAttributes() Demo".
'     Assembly title is "CustAttrs1VB".

Aplica-se a

GetCustomAttributes(ParameterInfo)

Recupera um array dos atributos personalizados aplicados a um parâmetro de método. Um parâmetro especifica o parâmetro do método.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::ParameterInfo ^ element);
public static Attribute[] GetCustomAttributes(System.Reflection.ParameterInfo element);
static member GetCustomAttributes : System.Reflection.ParameterInfo -> Attribute[]
Public Shared Function GetCustomAttributes (element As ParameterInfo) As Attribute()

Parâmetros

element
ParameterInfo

Um objeto derivado da ParameterInfo classe que descreve um parâmetro de um membro de uma classe.

Devoluções

Um Attribute array que contenha os atributos personalizados aplicados a element, ou um array vazio se não existirem tais atributos personalizados.

Exceções

element é null.

Um tipo de atributo personalizado não pode ser carregado.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando a ParameterInfo como parâmetro.

using System;
using System.Reflection;
using System.ComponentModel;

namespace CustAttrs5CS {
    public class AClass {
        public void ParamArrayAndDesc(
            // Add ParamArray (with the keyword) and Description attributes.
            [Description("This argument is a ParamArray")]
            params int[] args)
        {}
    }

    class DemoClass {
        static void Main(string[] args) {
            // Get the Class type to access its metadata.
            Type clsType = typeof(AClass);
            // Get the type information for the method.
            MethodInfo mInfo = clsType.GetMethod("ParamArrayAndDesc");
            if (mInfo != null) {
                // Get the parameter information.
                ParameterInfo[] pInfo = mInfo.GetParameters();
                if (pInfo != null) {
                    // Iterate through all the attributes for the parameter.
                    foreach(Attribute attr in
                        Attribute.GetCustomAttributes(pInfo[0])) {
                        // Check for the ParamArray attribute.
                        if (attr.GetType() == typeof(ParamArrayAttribute))
                            Console.WriteLine("Parameter {0} for method {1} " +
                                "has the ParamArray attribute.",
                                pInfo[0].Name, mInfo.Name);
                        // Check for the Description attribute.
                        else if (attr.GetType() ==
                            typeof(DescriptionAttribute)) {
                            Console.WriteLine("Parameter {0} for method {1} " +
                                "has a description attribute.",
                                pInfo[0].Name, mInfo.Name);
                            Console.WriteLine("The description is: \"{0}\"",
                                ((DescriptionAttribute)attr).Description);
                        }
                    }
                }
            }
        }
    }
}

/*
 * Output:
 * Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
 * Parameter args for method ParamArrayAndDesc has a description attribute.
 * The description is: "This argument is a ParamArray"
 */
open System
open System.Reflection
open System.ComponentModel

type AClass() =
    member _.ParamArrayAndDesc(
        // Add ParamArray and Description attributes.
        [<Description "This argument is a ParamArray">]
        [<ParamArray>]
        args: int[]) = ()

// Get the Class type to access its metadata.
let clsType = typeof<AClass>

// Get the type information for the method.
let mInfo = clsType.GetMethod "ParamArrayAndDesc"
if mInfo <> null then
    // Get the parameter information.
    let pInfo = mInfo.GetParameters()
    if pInfo <> null then
        // Iterate through all the attributes for the parameter.
        for attr in Attribute.GetCustomAttributes pInfo[0] do
            match attr with 
            // Check for the ParamArray attribute.
            | :? ParamArrayAttribute ->
                printfn $"Parameter {pInfo[0].Name} for method {mInfo.Name} has the ParamArray attribute."
                                
            // Check for the Description attribute.
            | :? DescriptionAttribute as attr ->
                printfn $"Parameter {pInfo[0].Name} for method {mInfo.Name} has a description attribute."
                printfn $"The description is: \"{attr.Description}\""
            | _ -> ()

// Output:
// Parameter args for method ParamArrayAndDesc has a description attribute.
// The description is: "This argument is a ParamArray"
// Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
Imports System.Reflection
Imports System.ComponentModel

Module DemoModule
    Public Class AClass
        ' Add Description and ParamArray (with the keyword) attributes.
        Public Sub ParamArrayAndDesc( _
            <Description("This argument is a ParamArray")> _
            ByVal ParamArray args() As Integer)
        End Sub
    End Class

    Sub Main()
        ' Get the Class type to access its metadata.
        Dim clsType As Type = GetType(AClass)
        ' Get the type information for the method.
        Dim mInfo As MethodInfo = clsType.GetMethod("ParamArrayAndDesc")
        ' Get the Parameter information for the method.
        Dim pInfo() As ParameterInfo = mInfo.GetParameters()
        Dim attr As Attribute
        ' Iterate through each attribute of the parameter.
        For Each attr In Attribute.GetCustomAttributes(pInfo(0))
            ' Check for the ParamArray attribute.
            If TypeOf attr Is ParamArrayAttribute Then
                ' Convert the attribute to access its data.
                Dim paAttr As ParamArrayAttribute = _
                    CType(attr, ParamArrayAttribute)
                Console.WriteLine("Parameter {0} for method {1} has the " + _
                    "ParamArray attribute.", pInfo(0).Name, mInfo.Name)
            ' Check for the Description attribute.
            ElseIf TypeOf attr Is DescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim descAttr As DescriptionAttribute = _
                    CType(attr, DescriptionAttribute)
                Console.WriteLine("Parameter {0} for method {1} has a description " + _
                    "attribute. The description is:", pInfo(0).Name, mInfo.Name)
                Console.WriteLine(descAttr.Description)
            End If
        Next
    End Sub
End Module

' Output:
' Parameter args for method ParamArrayAndDesc has the ParamArray attribute.
' Parameter args for method ParamArrayAndDesc has a description attribute. The description is:
' This argument is a ParamArray

Observações

Se element representa um parâmetro num método de um tipo derivado, o valor de retorno inclui os atributos personalizados herdáveis aplicados ao mesmo parâmetro nos métodos base sobrepostos.

Aplica-se a

GetCustomAttributes(Module)

Recupera um array dos atributos personalizados aplicados a um módulo. Um parâmetro especifica o módulo.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::Module ^ element);
public static Attribute[] GetCustomAttributes(System.Reflection.Module element);
static member GetCustomAttributes : System.Reflection.Module -> Attribute[]
Public Shared Function GetCustomAttributes (element As Module) As Attribute()

Parâmetros

element
Module

Um objeto derivado da Module classe que descreve um ficheiro executável portátil.

Devoluções

Um Attribute array que contenha os atributos personalizados aplicados a element, ou um array vazio se não existirem tais atributos personalizados.

Exceções

element é null.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando a Module como parâmetro.

using System;
using System.Reflection;
using System.ComponentModel;

// Assign some attributes to the module.
[module:Description("A sample description")]

// Set the module's CLSCompliant attribute to false
// The CLSCompliant attribute is applicable for /target:module.
[module:CLSCompliant(false)]

namespace CustAttrs2CS {
    class DemoClass {
        static void Main(string[] args) {
            Type clsType = typeof(DemoClass);
            // Get the Module type to access its metadata.
            Module module = clsType.Module;

            // Iterate through all the attributes for the module.
            foreach(Attribute attr in Attribute.GetCustomAttributes(module)) {
                // Check for the Description attribute.
                if (attr.GetType() == typeof(DescriptionAttribute))
                    Console.WriteLine("Module {0} has the description " +
                        "\"{1}\".", module.Name,
                        ((DescriptionAttribute)attr).Description);
                // Check for the CLSCompliant attribute.
                else if (attr.GetType() == typeof(CLSCompliantAttribute))
                    Console.WriteLine("Module {0} {1} CLSCompliant.",
                        module.Name,
                        ((CLSCompliantAttribute)attr).IsCompliant ?
                            "is" : "is not");
            }
        }
    }
}

/*
 * Output:
 * Module CustAttrs2CS.exe is not CLSCompliant.
 * Module CustAttrs2CS.exe has the description "A sample description".
 */
open System
open System.ComponentModel

// Assign some attributes to the module.
[<``module``: Description "A sample description">]

// Set the module's CLSCompliant attribute to false
// The CLSCompliant attribute is applicable for /target:module.
[<``module``: CLSCompliant false>]
do ()

type DemoClass = class end

// Get the Module type to access its metadata.
let ilmodule = typeof<DemoClass>.Module

// Iterate through all the attributes for the module.
for attr in Attribute.GetCustomAttributes ilmodule do
    match attr with
    // Check for the Description attribute.
    | :? DescriptionAttribute as attr ->
        printfn $"Module {ilmodule.Name} has the description \"{attr.Description}\"."
                
    // Check for the CLSCompliant attribute.
    | :? CLSCompliantAttribute as attr ->
        printfn $"""Module {ilmodule.Name} {if attr.IsCompliant then "is" else "is not"} CLSCompliant."""
    | _ -> ()
    
// Output:
// Module CustAttrs2CS.exe is not CLSCompliant.
// Module CustAttrs2CS.exe has the description "A sample description".
Imports System.Reflection
Imports System.ComponentModel

' Give the Module some attributes.
<Module: Description("A sample description")> 

' Make the CLSCompliant attribute False.
' The CLSCompliant attribute is applicable for /target:module.
<Module: CLSCompliant(False)> 

Module DemoModule

    Sub Main()
        ' Get the Module type to access its metadata.
        Dim modType As Reflection.Module = GetType(DemoModule).Module
        Dim attr As Attribute
        ' Iterate through all the attributes for the module.
        For Each attr In Attribute.GetCustomAttributes(modType)
            ' Check for the Description attribute.
            If TypeOf attr Is DescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim descAttr As DescriptionAttribute = _
                    CType(attr, DescriptionAttribute)
                Console.WriteLine("Module {0} has the description ""{1}"".", _
                    modType.Name, descAttr.Description)

            ' Check for the CLSCompliant attribute.
            ElseIf TypeOf attr Is CLSCompliantAttribute Then
                ' Convert the attribute to access its data.
                Dim CLSCompAttr As CLSCompliantAttribute = _
                    CType(attr, CLSCompliantAttribute)
                Dim strCompliant As String
                If CLSCompAttr.IsCompliant Then
                    strCompliant = "is"
                Else
                    strCompliant = "is not"
                End If
                Console.WriteLine("Module {0} {1} CLSCompliant.", _
                    modType.Name, strCompliant)
            End If
        Next
    End Sub
End Module

' Output:
' Module CustAttrs2VB.exe has the description "A sample description".
' Module CustAttrs2VB.exe is not CLSCompliant.

Aplica-se a

GetCustomAttributes(MemberInfo)

Recupera um array dos atributos personalizados aplicados a um membro de um tipo. Um parâmetro especifica o membro.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::MemberInfo ^ element);
public static Attribute[] GetCustomAttributes(System.Reflection.MemberInfo element);
static member GetCustomAttributes : System.Reflection.MemberInfo -> Attribute[]
Public Shared Function GetCustomAttributes (element As MemberInfo) As Attribute()

Parâmetros

element
MemberInfo

Um objeto derivado da MemberInfo classe que descreve um construtor, evento, corpo, método ou propriedade membro de uma classe.

Devoluções

Um Attribute array que contenha os atributos personalizados aplicados a element, ou um array vazio se não existirem tais atributos personalizados.

Exceções

element é null.

element não é um construtor, método, propriedade, evento, tipo ou campo.

Um tipo de atributo personalizado não pode ser carregado.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttribute, tomando a MemberInfo como parâmetro.

using System;
using System.Reflection;
using System.Security;
using System.Runtime.InteropServices;

namespace CustAttrs4CS
{

    // Define an enumeration of Win32 unmanaged types
    public enum UnmanagedType
    {
        User,
        GDI,
        Kernel,
        Shell,
        Networking,
        Multimedia
    }

    // Define the Unmanaged attribute.
    public class UnmanagedAttribute : Attribute
    {
        // Storage for the UnmanagedType value.
        protected UnmanagedType thisType;

        // Set the unmanaged type in the constructor.
        public UnmanagedAttribute(UnmanagedType type)
        {
            thisType = type;
        }

        // Define a property to get and set the UnmanagedType value.
        public UnmanagedType Win32Type
        {
            get { return thisType; }
            set { thisType = Win32Type; }
        }
    }

    // Create a class for an imported Win32 unmanaged function.
    public class Win32 {
        [DllImport("user32.dll", CharSet = CharSet.Unicode)]
        public static extern int MessageBox(int hWnd, String text,
            String caption, uint type);
    }

    public class AClass {
        // Add some attributes to Win32CallMethod.
        [Obsolete("This method is obsolete. Use managed MsgBox instead.")]
        [Unmanaged(UnmanagedType.User)]
        public void Win32CallMethod()
        {
            Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0);
        }
    }

    class DemoClass {
        static void Main(string[] args)
            {
            // Get the AClass type to access its metadata.
            Type clsType = typeof(AClass);
            // Get the type information for Win32CallMethod.
            MethodInfo mInfo = clsType.GetMethod("Win32CallMethod");
            if (mInfo != null)
            {
                // Iterate through all the attributes of the method.
                foreach(Attribute attr in
                    Attribute.GetCustomAttributes(mInfo)) {
                    // Check for the Obsolete attribute.
                    if (attr.GetType() == typeof(ObsoleteAttribute))
                    {
                        Console.WriteLine("Method {0} is obsolete. " +
                            "The message is:",
                            mInfo.Name);
                        Console.WriteLine("  \"{0}\"",
                            ((ObsoleteAttribute)attr).Message);
                    }

                    // Check for the Unmanaged attribute.
                    else if (attr.GetType() == typeof(UnmanagedAttribute))
                    {
                        Console.WriteLine(
                            "This method calls unmanaged code.");
                        Console.WriteLine(
                            String.Format("The Unmanaged attribute type is {0}.",
                                          ((UnmanagedAttribute)attr).Win32Type));
                        AClass myCls = new AClass();
                        myCls.Win32CallMethod();
                    }
                }
            }
        }
    }
}

/*

This code example produces the following results.

First, the compilation yields the warning, "... This method is
obsolete. Use managed MsgBox instead."
Second, execution yields a message box with a title of "Caution!"
and message text of "This is an unmanaged call."
Third, the following text is displayed in the console window:

Method Win32CallMethod is obsolete. The message is:
  "This method is obsolete. Use managed MsgBox instead."
This method calls unmanaged code.
The Unmanaged attribute type is User.

*/
open System
open System.Runtime.InteropServices

// Define an enumeration of Win32 unmanaged types
type UnmanagedType =
    | User = 0
    | GDI = 1
    | Kernel = 2
    | Shell = 3
    | Networking = 4
    | Multimedia = 5

// Define the Unmanaged attribute.
type UnmanagedAttribute(unmanagedType) =
    inherit Attribute()
    
    // Define a property to get and set the UnmanagedType value.
    member val Win32Type = unmanagedType with get, set

// Create a module for an imported Win32 unmanaged function.
module Win32 =
    [<DllImport("user32.dll", CharSet = CharSet.Unicode)>]
    extern int MessageBox(IntPtr hWnd, String text, String caption, uint ``type``)

type AClass() =
    // Add some attributes to Win32CallMethod.
    [<Obsolete "This method is obsolete. Use managed MsgBox instead.">]
    [<Unmanaged(UnmanagedType.User)>]
    member _.Win32CallMethod () =
        Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0u)

// Get the AClass type to access its metadata.
let clsType = typeof<AClass>
// Get the type information for Win32CallMethod.
let mInfo = clsType.GetMethod "Win32CallMethod"
if mInfo <> null then
    // Iterate through all the attributes of the method.
    for attr in Attribute.GetCustomAttributes mInfo do
        match attr with 
        // Check for the Obsolete attribute.
        | :? ObsoleteAttribute as attr ->
            printfn $"Method {mInfo.Name} is obsolete. The message is:"
            printfn $"  \"{attr.Message}\""

        // Check for the Unmanaged attribute.
        | :? UnmanagedAttribute as attr ->
            printfn "This method calls unmanaged code."
            printfn $"The Unmanaged attribute type is {attr.Win32Type}."
            let myCls = AClass()
            myCls.Win32CallMethod() |> ignore
        | _ -> ()

// This code example produces the following results.
//
// First, the compilation yields the warning, "... This method is
// obsolete. Use managed MsgBox instead."
// Second, execution yields a message box with a title of "Caution!"
// and message text of "This is an unmanaged call."
// Third, the following text is displayed in the console window:

// Method Win32CallMethod is obsolete. The message is:
//   "This method is obsolete. Use managed MsgBox instead."
// This method calls unmanaged code.
// The Unmanaged attribute type is User.
Imports System.Reflection
Imports System.Security
Imports System.Runtime.InteropServices

' Define an enumeration of Win32 unmanaged types
Public Enum UnmanagedType
    User
    GDI
    Kernel
    Shell
    Networking
    Multimedia
End Enum 'UnmanagedType

' Define the Unmanaged attribute.
Public Class UnmanagedAttribute 
             Inherits Attribute

    ' Storage for the UnmanagedType value.
    Protected thisType As UnmanagedType
    
    ' Set the unmanaged type in the constructor.
    Public Sub New(ByVal type As UnmanagedType) 
        thisType = type
    End Sub
    
    ' Define a property to get and set the UnmanagedType value.
    Public Property Win32Type() As UnmanagedType 
        Get
            Return thisType
        End Get
        Set
            thisType = Win32Type
        End Set
    End Property
End Class

' Create a class for an imported Win32 unmanaged function.
Public Class Win32
    <DllImport("user32.dll", CharSet:=CharSet.Unicode)> _
    Public Shared Function MessageBox(ByVal hWnd As Integer, _
                                      ByVal Text As String, _
                                      ByVal caption As String, _
                                      ByVal type As Integer) As Integer
    End Function 'MessageBox
End Class

Public Class AClass
    ' Add some attributes to Win32CallMethod.
    <Obsolete("This method is obsolete. Use managed MsgBox instead."), _
     Unmanaged(UnmanagedType.User)>  _
    Public Sub Win32CallMethod() 
        Win32.MessageBox(0, "This is an unmanaged call.", "Caution!", 0)    
    End Sub
End Class

Class DemoClass
    Shared Sub Main(ByVal args() As String) 
        ' Get the AClass type to access its metadata.
        Dim clsType As Type = GetType(AClass)
        ' Get the type information for Win32CallMethod.
        Dim mInfo As MethodInfo = clsType.GetMethod("Win32CallMethod")
        If Not (mInfo Is Nothing) Then
            ' Iterate through all the attributes of the method.
            Dim attr As Attribute
            For Each attr In  Attribute.GetCustomAttributes(mInfo)
                ' Check for the Obsolete attribute.
                If attr.GetType().Equals(GetType(ObsoleteAttribute)) Then
                    Console.WriteLine("Method {0} is obsolete. The message is:", mInfo.Name)
                    Console.WriteLine("  ""{0}""", CType(attr, ObsoleteAttribute).Message)
                ' Check for the Unmanaged attribute.
                ElseIf attr.GetType().Equals(GetType(UnmanagedAttribute)) Then
                    Console.WriteLine("This method calls unmanaged code.")
                    Console.WriteLine( _
                            String.Format("The Unmanaged attribute type is {0}.", _
                            CType(attr, UnmanagedAttribute).Win32Type))
                    Dim myCls As New AClass()
                    myCls.Win32CallMethod()
                End If
            Next attr
        End If
    End Sub
End Class

'
'This code example produces the following results. 
'
'First, the compilation yields the warning, "... This method is 
'obsolete. Use managed MsgBox instead."
'Second, execution yields a message box with a title of "Caution!" 
'and message text of "This is an unmanaged call." 
'Third, the following text is displayed in the console window:
'
'Method Win32CallMethod is obsolete. The message is:
'  "This method is obsolete. Use managed MsgBox instead."
'This method calls unmanaged code.
'The Unmanaged attribute type is User.
'

Observações

O valor de retorno contém os atributos personalizados para os antepassados de element.

Note

A partir do .NET Framework versão 2.0, este método devolve atributos de segurança nos métodos, construtores e tipos se os atributos estiverem armazenados no novo formato de metadados. Assemblies compilados com a versão 2.0 ou posterior utilizam o novo formato. Assemblies dinâmicos e assemblies compilados com versões anteriores do .NET Framework utilizam o antigo formato XML. Ver Emissão de Atributos de Segurança Declarativa.

Aplica-se a

GetCustomAttributes(Assembly)

Recupera um array dos atributos personalizados aplicados a uma assembleia. Um parâmetro especifica a montagem.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::Assembly ^ element);
public static Attribute[] GetCustomAttributes(System.Reflection.Assembly element);
static member GetCustomAttributes : System.Reflection.Assembly -> Attribute[]
Public Shared Function GetCustomAttributes (element As Assembly) As Attribute()

Parâmetros

element
Assembly

Um objeto derivado da Assembly classe que descreve uma coleção reutilizável de módulos.

Devoluções

Um Attribute array que contenha os atributos personalizados aplicados a element, ou um array vazio se não existirem tais atributos personalizados.

Exceções

element é null.

Exemplos

O exemplo seguinte recupera os atributos personalizados encontrados na montagem atual.

using System;
using System.Reflection;

[assembly: AssemblyTitle("CustAttrs1CS")]
[assembly: AssemblyDescription("GetCustomAttributes() Demo")]
[assembly: AssemblyCompany("Microsoft")]

class Example {
    static void Main() {
        // Get the Assembly object to access its metadata.
        Assembly assy = typeof(Example).Assembly;

        // Iterate through the attributes for the assembly.
        foreach(Attribute attr in Attribute.GetCustomAttributes(assy)) {
            // Check for the AssemblyTitle attribute.
            if (attr.GetType() == typeof(AssemblyTitleAttribute))
                Console.WriteLine("Assembly title is \"{0}\".",
                    ((AssemblyTitleAttribute)attr).Title);

            // Check for the AssemblyDescription attribute.
            else if (attr.GetType() ==
                typeof(AssemblyDescriptionAttribute))
                Console.WriteLine("Assembly description is \"{0}\".",
                    ((AssemblyDescriptionAttribute)attr).Description);

            // Check for the AssemblyCompany attribute.
            else if (attr.GetType() == typeof(AssemblyCompanyAttribute))
                Console.WriteLine("Assembly company is {0}.",
                    ((AssemblyCompanyAttribute)attr).Company);
        }
   }
}
// The example displays the following output:
//     Assembly title is "CustAttrs1CS".
//     Assembly description is "GetCustomAttributes() Demo".
//     Assembly company is Microsoft.
open System
open System.Reflection

[<assembly: AssemblyTitle "CustAttrs1CS">]
[<assembly: AssemblyDescription "GetCustomAttributes() Demo">]
[<assembly: AssemblyCompany"Microsoft">]
do ()

type Example = class end

// Get the Assembly object to access its metadata.
let assembly = typeof<Example>.Assembly

// Iterate through the attributes for the assembly.
for attr in Attribute.GetCustomAttributes assembly do
    match attr with
    // Check for the AssemblyTitle attribute.
    | :? AssemblyTitleAttribute as attr ->    
        printfn $"Assembly title is \"{attr.Title}\"."
    // Check for the AssemblyDescription attribute.
    | :? AssemblyDescriptionAttribute as attr ->
        printfn $"Assembly description is \"{attr.Description}\"."
    // Check for the AssemblyCompany attribute.
    | :? AssemblyCompanyAttribute as attr ->
        printfn $"Assembly company is {attr.Company}."
    | _ -> ()
    
// The example displays the following output:
//     Assembly title is "CustAttrs1CS".
//     Assembly description is "GetCustomAttributes() Demo".
//     Assembly company is Microsoft.
Imports System.Reflection

<Assembly: AssemblyTitle("CustAttrs1VB")> 
<Assembly: AssemblyDescription("GetCustomAttributes() Demo")> 
<Assembly: AssemblyCompany("Microsoft")> 

Module Example
    Sub Main()
        ' Get the Assembly type to access its metadata.
        Dim assy As Reflection.Assembly = GetType(Example).Assembly

        ' Iterate through all the attributes for the assembly.
        For Each attr As Attribute In Attribute.GetCustomAttributes(assy)
            ' Check for the AssemblyTitle attribute.
            If TypeOf attr Is AssemblyTitleAttribute Then
                ' Convert the attribute to access its data.
                Dim attrTitle As AssemblyTitleAttribute = _
                    CType(attr, AssemblyTitleAttribute)
                Console.WriteLine("Assembly title is ""{0}"".", _
                    attrTitle.Title)

            ' Check for the AssemblyDescription attribute.
            ElseIf TypeOf attr Is AssemblyDescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim attrDesc As AssemblyDescriptionAttribute = _
                    CType(attr, AssemblyDescriptionAttribute)
                Console.WriteLine("Assembly description is ""{0}"".", _
                    attrDesc.Description)

            ' Check for the AssemblyCompany attribute.
            ElseIf TypeOf attr Is AssemblyCompanyAttribute Then
                ' Convert the attribute to access its data.
                Dim attrComp As AssemblyCompanyAttribute = _
                    CType(attr, AssemblyCompanyAttribute)
                Console.WriteLine("Assembly company is {0}.", _
                    attrComp.Company)
            End If
        Next
    End Sub
End Module
' The example displays the following output:
'     Assembly company is Microsoft.
'     Assembly description is "GetCustomAttributes() Demo".
'     Assembly title is "CustAttrs1VB".

Observações

Note

A partir da versão 2.0 do .NET Framework, este método devolve atributos de segurança se os atributos estiverem armazenados no novo formato de metadados. Assemblies compilados com a versão 2.0 ou posterior utilizam o novo formato. Assemblies dinâmicos e assemblies compilados com versões anteriores do .NET Framework utilizam o antigo formato XML. Ver Emissão de Atributos de Segurança Declarativa.

Aplica-se a

GetCustomAttributes(Module, Boolean)

Recupera um array dos atributos personalizados aplicados a um módulo. Os parâmetros especificam o módulo e uma opção de pesquisa ignorada.

public:
 static cli::array <Attribute ^> ^ GetCustomAttributes(System::Reflection::Module ^ element, bool inherit);
public static Attribute[] GetCustomAttributes(System.Reflection.Module element, bool inherit);
static member GetCustomAttributes : System.Reflection.Module * bool -> Attribute[]
Public Shared Function GetCustomAttributes (element As Module, inherit As Boolean) As Attribute()

Parâmetros

element
Module

Um objeto derivado da Module classe que descreve um ficheiro executável portátil.

inherit
Boolean

Este parâmetro é ignorado e não afeta o funcionamento deste método.

Devoluções

Um Attribute array que contenha os atributos personalizados aplicados a element, ou um array vazio se não existirem tais atributos personalizados.

Exceções

element é null.

Exemplos

O exemplo de código seguinte demonstra o uso de GetCustomAttributes, tomando a Module como parâmetro.

using System;
using System.Reflection;
using System.ComponentModel;

// Assign some attributes to the module.
[module:Description("A sample description")]

// Set the module's CLSCompliant attribute to false
// The CLSCompliant attribute is applicable for /target:module.
[module:CLSCompliant(false)]

namespace CustAttrs2CS {
    class DemoClass {
        static void Main(string[] args) {
            Type clsType = typeof(DemoClass);
            // Get the Module type to access its metadata.
            Module module = clsType.Module;

            // Iterate through all the attributes for the module.
            foreach(Attribute attr in Attribute.GetCustomAttributes(module)) {
                // Check for the Description attribute.
                if (attr.GetType() == typeof(DescriptionAttribute))
                    Console.WriteLine("Module {0} has the description " +
                        "\"{1}\".", module.Name,
                        ((DescriptionAttribute)attr).Description);
                // Check for the CLSCompliant attribute.
                else if (attr.GetType() == typeof(CLSCompliantAttribute))
                    Console.WriteLine("Module {0} {1} CLSCompliant.",
                        module.Name,
                        ((CLSCompliantAttribute)attr).IsCompliant ?
                            "is" : "is not");
            }
        }
    }
}

/*
 * Output:
 * Module CustAttrs2CS.exe is not CLSCompliant.
 * Module CustAttrs2CS.exe has the description "A sample description".
 */
open System
open System.ComponentModel

// Assign some attributes to the module.
[<``module``: Description "A sample description">]

// Set the module's CLSCompliant attribute to false
// The CLSCompliant attribute is applicable for /target:module.
[<``module``: CLSCompliant false>]
do ()

type DemoClass = class end

// Get the Module type to access its metadata.
let ilmodule = typeof<DemoClass>.Module

// Iterate through all the attributes for the module.
for attr in Attribute.GetCustomAttributes ilmodule do
    match attr with
    // Check for the Description attribute.
    | :? DescriptionAttribute as attr ->
        printfn $"Module {ilmodule.Name} has the description \"{attr.Description}\"."
                
    // Check for the CLSCompliant attribute.
    | :? CLSCompliantAttribute as attr ->
        printfn $"""Module {ilmodule.Name} {if attr.IsCompliant then "is" else "is not"} CLSCompliant."""
    | _ -> ()
    
// Output:
// Module CustAttrs2CS.exe is not CLSCompliant.
// Module CustAttrs2CS.exe has the description "A sample description".
Imports System.Reflection
Imports System.ComponentModel

' Give the Module some attributes.
<Module: Description("A sample description")> 

' Make the CLSCompliant attribute False.
' The CLSCompliant attribute is applicable for /target:module.
<Module: CLSCompliant(False)> 

Module DemoModule

    Sub Main()
        ' Get the Module type to access its metadata.
        Dim modType As Reflection.Module = GetType(DemoModule).Module
        Dim attr As Attribute
        ' Iterate through all the attributes for the module.
        For Each attr In Attribute.GetCustomAttributes(modType)
            ' Check for the Description attribute.
            If TypeOf attr Is DescriptionAttribute Then
                ' Convert the attribute to access its data.
                Dim descAttr As DescriptionAttribute = _
                    CType(attr, DescriptionAttribute)
                Console.WriteLine("Module {0} has the description ""{1}"".", _
                    modType.Name, descAttr.Description)

            ' Check for the CLSCompliant attribute.
            ElseIf TypeOf attr Is CLSCompliantAttribute Then
                ' Convert the attribute to access its data.
                Dim CLSCompAttr As CLSCompliantAttribute = _
                    CType(attr, CLSCompliantAttribute)
                Dim strCompliant As String
                If CLSCompAttr.IsCompliant Then
                    strCompliant = "is"
                Else
                    strCompliant = "is not"
                End If
                Console.WriteLine("Module {0} {1} CLSCompliant.", _
                    modType.Name, strCompliant)
            End If
        Next
    End Sub
End Module

' Output:
' Module CustAttrs2VB.exe has the description "A sample description".
' Module CustAttrs2VB.exe is not CLSCompliant.

Observações

O valor de retorno contém os atributos personalizados para os antepassados de element se inherit for true.

Aplica-se a