PropertyAttributes Enumerazione

Definizione

public enum class PropertyAttributes

[System.Flags]
public enum PropertyAttributes

[System.Flags]
[System.Serializable]
public enum PropertyAttributes

[System.Flags]
[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public enum PropertyAttributes

[<System.Flags>]
type PropertyAttributes = 

[<System.Flags>]
[<System.Serializable>]
type PropertyAttributes = 

[<System.Flags>]
[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type PropertyAttributes = 

Public Enum PropertyAttributes

Ereditarietà

Object

ValueType

Enum

PropertyAttributes

Attributi

FlagsAttribute SerializableAttribute ComVisibleAttribute

Campi

Esempio

Nell'esempio seguente vengono compilate tre proprietà e viene visualizzato il PropertyAttributes valore enumerato. Si noti che la proprietà di sola lettura non dispone di setter e pertanto non può essere modificata da.Caption = statement.

using System;
using System.Reflection;

 // Define three properties: one read-write, one default,
 // and one read only.
public class Aproperty
    // Define a read-write property.
{
    private string caption = "A Default caption";
    public string Caption
    {
        get{return caption;}
        set
        {
            if (caption != value){caption = value;}
        }
    }
}
public class Bproperty
    // Define a default property.
{
    private string caption  = "B Default caption";
    public string this [int index]
    {
        get {return "1";}
    }
    public string Caption
    {

        get{return caption;}
        set
        {
            if (caption != value){caption = value;}
        }
    }
}
public class Cproperty
    // Define a read-only property.
{
    private string caption = "C Default caption";
    public string Caption
    {
        get{return caption;}
        // No setting is allowed, because this is a read-only property.
    }
}

class propertyattributesenum
{
    public static int Main(string[] args)
    {
        Console.WriteLine("\nReflection.PropertyAttributes");

        // Determine whether a property exists, and change its value.
        Aproperty Mypropertya = new Aproperty();
        Bproperty Mypropertyb = new Bproperty();
        Cproperty Mypropertyc = new Cproperty();

        Console.Write("\n1. Mypropertya.Caption = " + Mypropertya.Caption );

        Console.Write("\n1. Mypropertyb.Caption = " + Mypropertyb.Caption );

        Console.Write("\n1. Mypropertyc.Caption = " + Mypropertyc.Caption );

        // Only Mypropertya can be changed, as Mypropertyb is read-only.
        Mypropertya.Caption = "A- This is changed.";
        Mypropertyb.Caption = "B- This is changed.";
        // Note that Mypropertyc is not changed because it is read only

        Console.Write("\n\n2. Mypropertya.Caption = " + Mypropertya.Caption );

        Console.Write("\n2. Mypropertyb.Caption = " + Mypropertyb.Caption );

        Console.Write("\n2. Mypropertyc.Caption = " + Mypropertyc.Caption );

        // Get the PropertyAttributes enumeration of the property.
        // Get the type.
        Type MyTypea = Type.GetType("Aproperty");
        Type MyTypeb = Type.GetType("Bproperty");
        Type MyTypec = Type.GetType("Cproperty");

        // Get the property attributes.
        PropertyInfo Mypropertyinfoa = MyTypea.GetProperty("Caption");
        PropertyAttributes Myattributesa = Mypropertyinfoa.Attributes;
        PropertyInfo Mypropertyinfob = MyTypeb.GetProperty("Item");
        PropertyAttributes Myattributesb = Mypropertyinfob.Attributes;
        PropertyInfo Mypropertyinfoc = MyTypec.GetProperty("Caption");
        PropertyAttributes Myattributesc = Mypropertyinfoc.Attributes;

        // Display the property attributes value.

        Console.Write("\n\na- " + Myattributesa.ToString());

        Console.Write("\nb- " + Myattributesb.ToString());

        Console.Write("\nc- " + Myattributesc.ToString());
        return 0;
    }
}

// This example displays the following output to the console
//
// Reflection.PropertyAttributes
//
// 1. Mypropertya.Caption = A Default caption
// 1. Mypropertyb.Caption = B Default caption
// 1. Mypropertyc.Caption = C Default caption
//
// 2. Mypropertya.Caption = A- This is changed.
// 2. Mypropertyb.Caption = B- This is changed.
// 2. Mypropertyc.Caption = C Default caption
//
// a- None
// b- None
// c- None

Imports System.Reflection

' Make three properties, one read-write, one default,
' and one read-only. 
Public Class Aproperty
    ' Define a read-write property.
    Private myCaption As String = "A Default caption"

    Public Property Caption() As String
        Get
            Return myCaption
        End Get
        Set(ByVal Value As String)
            If myCaption <> value Then
                myCaption = value
            End If
        End Set
    End Property
End Class

Public Class Bproperty
    ' Define a default property.
    Private myCaption As String = "B Default caption"

    Default Public ReadOnly Property Item(ByVal index As Integer) As String
        Get
            Return "1"
        End Get
    End Property

    Public Property Caption() As String

        Get
            Return myCaption
        End Get
        Set(ByVal Value As String)
            If myCaption <> value Then
                myCaption = value
            End If
        End Set
    End Property
End Class

Public Class Cproperty
    ' Define a read-only property.
    Private myCaption As String = "C Default caption"

    Public ReadOnly Property Caption() As String
        Get
            Return myCaption
        End Get
        'No setting is allowed because this property is read-only.
    End Property
End Class


Class propertyattributesenum

    Public Shared Function Main() As Integer
        Console.WriteLine(ControlChars.CrLf & "Reflection.PropertyAttributes")

        ' Determine whether a property exists, and change its value.
        Dim Mypropertya As New Aproperty()
        Dim Mypropertyb As New Bproperty()
        Dim Mypropertyc As New Cproperty()

        Console.Write(ControlChars.CrLf & "1. Mypropertya.Caption = " & _
           Mypropertya.Caption)

        Console.Write(ControlChars.CrLf & "1. Mypropertyb.Caption = " & _
           Mypropertyb.Caption)

        Console.Write(ControlChars.CrLf & "1. Mypropertyc.Caption = " & _
           Mypropertyc.Caption)

        ' Only Mypropertya can be changed because Mypropertyb is read-only.
        Mypropertya.Caption = "A- This is changed."
        Mypropertyb.Caption = "B- This is changed."
        ' Note that Mypropertyc is not changed, because it is read-only.
        Console.Write(ControlChars.CrLf & ControlChars.CrLf & _
           "2. Mypropertya.Caption = " & Mypropertya.Caption)

        Console.Write(ControlChars.CrLf & "2. Mypropertyb.Caption = " & _
           Mypropertyb.Caption)

        Console.Write(ControlChars.CrLf + "2. Mypropertyc.Caption = " & _
           Mypropertyc.Caption)

        ' Get the PropertyAttributes Enumeration of the property.
        ' Get the type.
        Dim MyTypea As Type = Type.GetType("Aproperty")
        Dim MyTypeb As Type = Type.GetType("Bproperty")
        Dim MyTypec As Type = Type.GetType("Cproperty")

        ' Get the property attributes.
        Dim Mypropertyinfoa As PropertyInfo = MyTypea.GetProperty("Caption")
        Dim Myattributesa As PropertyAttributes = Mypropertyinfoa.Attributes
        Dim Mypropertyinfob As PropertyInfo = MyTypeb.GetProperty("Item")
        Dim Myattributesb As PropertyAttributes = Mypropertyinfob.Attributes
        Dim Mypropertyinfoc As PropertyInfo = MyTypec.GetProperty("Caption")
        Dim Myattributesc As PropertyAttributes = Mypropertyinfoc.Attributes

        ' Display the property attributes value.
        Console.Write(ControlChars.CrLf & ControlChars.CrLf & "a- " & _
           Myattributesa.ToString())

        Console.Write(ControlChars.CrLf & "b- " & Myattributesb.ToString())

        Console.Write(ControlChars.CrLf & "c- " & Myattributesc.ToString())
        Return 0
    End Function'    End Function
End Class

' This example displays the following output to the console
'
' Reflection.PropertyAttributes
'
' 1. Mypropertya.Caption = A Default caption
' 1. Mypropertyb.Caption = B Default caption
' 1. Mypropertyc.Caption = C Default caption
'
' 2. Mypropertya.Caption = A- This is changed.
' 2. Mypropertyb.Caption = B- This is changed.
' 2. Mypropertyc.Caption = C Default caption
'
' a- None
' b- None
' c- None

Commenti

Per ottenere , ottenere PropertyAttributesprima la classe Type. TypeDa ottenere .PropertyInfo PropertyInfoDa ottenere .Attributes

Il valore enumerato è un numero che rappresenta l'OR bit per bit degli attributi implementati nel metodo .