MethodBuilder 類別

定義

public ref class MethodBuilder abstract : System::Reflection::MethodInfo

public ref class MethodBuilder sealed : System::Reflection::MethodInfo

public ref class MethodBuilder sealed : System::Reflection::MethodInfo, System::Runtime::InteropServices::_MethodBuilder

public abstract class MethodBuilder : System.Reflection.MethodInfo

public sealed class MethodBuilder : System.Reflection.MethodInfo

[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
public sealed class MethodBuilder : System.Reflection.MethodInfo, System.Runtime.InteropServices._MethodBuilder

[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class MethodBuilder : System.Reflection.MethodInfo, System.Runtime.InteropServices._MethodBuilder

type MethodBuilder = class
    inherit MethodInfo

[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)>]
type MethodBuilder = class
    inherit MethodInfo
    interface _MethodBuilder

[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type MethodBuilder = class
    inherit MethodInfo
    interface _MethodBuilder

Public MustInherit Class MethodBuilder
Inherits MethodInfo

Public NotInheritable Class MethodBuilder
Inherits MethodInfo

Public NotInheritable Class MethodBuilder
Inherits MethodInfo
Implements _MethodBuilder

繼承

Object

MemberInfo

MethodBase

MethodInfo

MethodBuilder

屬性

ClassInterfaceAttribute ComVisibleAttribute

實作

_MethodBuilder

範例

以下範例使用該 MethodBuilder 類別在動態型別中建立方法。

using System;
using System.Reflection;
using System.Reflection.Emit;

class DemoMethodBuilder
{
    public static void AddMethodDynamically (TypeBuilder myTypeBld,
                                             string mthdName,
                                             Type[] mthdParams,
                                             Type returnType,
                                             string mthdAction)
    {

        MethodBuilder myMthdBld = myTypeBld.DefineMethod(
                                             mthdName,
                                             MethodAttributes.Public |
                                             MethodAttributes.Static,
                                             returnType,
                                             mthdParams);

        ILGenerator ILout = myMthdBld.GetILGenerator();

        int numParams = mthdParams.Length;

        for (byte x=0; x < numParams; x++)
        {
            ILout.Emit(OpCodes.Ldarg_S, x);
        }

        if (numParams > 1)
        {
            for (int y=0; y<(numParams-1); y++)
            {
                switch (mthdAction)
                {
                    case "A": ILout.Emit(OpCodes.Add);
                              break;
                    case "M": ILout.Emit(OpCodes.Mul);
                              break;
                    default: ILout.Emit(OpCodes.Add);
                              break;
                }
            }
        }
        ILout.Emit(OpCodes.Ret);
    }

    public static void Main()
    {
        AppDomain myDomain = AppDomain.CurrentDomain;
        AssemblyName asmName = new AssemblyName();
        asmName.Name = "MyDynamicAsm";

        AssemblyBuilder myAsmBuilder = myDomain.DefineDynamicAssembly(
                                       asmName,
                                       AssemblyBuilderAccess.RunAndSave);

        ModuleBuilder myModule = myAsmBuilder.DefineDynamicModule("MyDynamicAsm",
                                                                  "MyDynamicAsm.dll");

        TypeBuilder myTypeBld = myModule.DefineType("MyDynamicType",
                                                    TypeAttributes.Public);

        // Get info from the user to build the method dynamically.
        Console.WriteLine("Let's build a simple method dynamically!");
        Console.WriteLine("Please enter a few numbers, separated by spaces.");
        string inputNums = Console.ReadLine();
        Console.Write("Do you want to [A]dd (default) or [M]ultiply these numbers? ");
        string myMthdAction = Console.ReadLine().ToUpper();
        Console.Write("Lastly, what do you want to name your new dynamic method? ");
        string myMthdName = Console.ReadLine();

        // Process inputNums into an array and create a corresponding Type array
        int index = 0;
        string[] inputNumsList = inputNums.Split();

        Type[] myMthdParams = new Type[inputNumsList.Length];
        object[] inputValsList = new object[inputNumsList.Length];

        foreach (string inputNum in inputNumsList)
        {
            inputValsList[index] = (object)Convert.ToInt32(inputNum);
                myMthdParams[index] = typeof(int);
                index++;
        }

        // Now, call the method building method with the parameters, passing the
        // TypeBuilder by reference.
        AddMethodDynamically(myTypeBld,
                             myMthdName,
                             myMthdParams,
                             typeof(int),
                             myMthdAction);

        Type myType = myTypeBld.CreateType();

        Console.WriteLine("---");
        Console.WriteLine("The result of {0} the inputted values is: {1}",
                          ((myMthdAction == "M") ? "multiplying" : "adding"),
                          myType.InvokeMember(myMthdName,
                          BindingFlags.InvokeMethod | BindingFlags.Public |
                          BindingFlags.Static,
                          null,
                          null,
                          inputValsList));
        Console.WriteLine("---");

        // Let's take a look at the method we created.
        // If you are interested in seeing the MSIL generated dynamically for the method
        // your program generated, change to the directory where you ran the compiled
        // code sample and type "ildasm MyDynamicAsm.dll" at the prompt. When the list
        // of manifest contents appears, click on "MyDynamicType" and then on the name of
        // of the method you provided during execution.

        myAsmBuilder.Save("MyDynamicAsm.dll");

        MethodInfo myMthdInfo = myType.GetMethod(myMthdName);
        Console.WriteLine("Your Dynamic Method: {0};", myMthdInfo.ToString());
    }
}

Imports System.Reflection
Imports System.Reflection.Emit

Class DemoMethodBuilder
   
   Public Shared Sub AddMethodDynamically(ByVal myTypeBld As TypeBuilder, _
                                          ByVal mthdName As String, _
                                          ByVal mthdParams() As Type, _
                                          ByVal returnType As Type, _
                                          ByVal mthdAction As String)
      
      Dim myMthdBld As MethodBuilder = myTypeBld.DefineMethod(mthdName, _
                                       MethodAttributes.Public Or MethodAttributes.Static, _
                                       returnType, _
                                       mthdParams)
      
      Dim ILout As ILGenerator = myMthdBld.GetILGenerator()
      
      Dim numParams As Integer = mthdParams.Length
      
      Dim x As Byte
      For x = 0 To numParams - 1
         ILout.Emit(OpCodes.Ldarg_S, x)
      Next x
      
      If numParams > 1 Then
         Dim y As Integer
         For y = 0 To (numParams - 1) - 1
            Select Case mthdAction
               Case "A"
                  ILout.Emit(OpCodes.Add)
               Case "M"
                  ILout.Emit(OpCodes.Mul)
               Case Else
                  ILout.Emit(OpCodes.Add)
            End Select
         Next y
      End If
      ILout.Emit(OpCodes.Ret)
   End Sub 
    
   
   Public Shared Sub Main()
      
      Dim myDomain As AppDomain = AppDomain.CurrentDomain
      Dim asmName As New AssemblyName()
      asmName.Name = "MyDynamicAsm"
      
      Dim myAsmBuilder As AssemblyBuilder = myDomain.DefineDynamicAssembly(asmName, _
                                            AssemblyBuilderAccess.RunAndSave)
      
      Dim myModule As ModuleBuilder = myAsmBuilder.DefineDynamicModule("MyDynamicAsm", _
                                                                       "MyDynamicAsm.dll")
      
      Dim myTypeBld As TypeBuilder = myModule.DefineType("MyDynamicType", TypeAttributes.Public)
      
      ' Get info from the user to build the method dynamically.
      Console.WriteLine("Let's build a simple method dynamically!")
      Console.WriteLine("Please enter a few numbers, separated by spaces.")
      Dim inputNums As String = Console.ReadLine()
      Console.Write("Do you want to [A]dd (default) or [M]ultiply these numbers? ")
      Dim myMthdAction As String = Console.ReadLine().ToUpper()
      Console.Write("Lastly, what do you want to name your new dynamic method? ")
      Dim myMthdName As String = Console.ReadLine()
      
      ' Process inputNums into an array and create a corresponding Type array 
      Dim index As Integer = 0
      Dim inputNumsList As String() = inputNums.Split()
      
      Dim myMthdParams(inputNumsList.Length - 1) As Type
      Dim inputValsList(inputNumsList.Length - 1) As Object
      
      
      Dim inputNum As String
      For Each inputNum In  inputNumsList
         inputValsList(index) = CType(Convert.ToInt32(inputNum), Object)
         myMthdParams(index) = GetType(Integer)
         index += 1
      Next inputNum
      
      ' Now, call the method building method with the parameters, passing the 
      ' TypeBuilder by reference.
      AddMethodDynamically(myTypeBld, myMthdName, myMthdParams, GetType(Integer), myMthdAction)
      
      Dim myType As Type = myTypeBld.CreateType()
     
      Dim description as String 
      If myMthdAction = "M" Then
         description = "multiplying"
      Else
         description = "adding"
      End If

      Console.WriteLine("---")
      Console.WriteLine("The result of {0} the values is: {1}", _
                         description, _
                         myType.InvokeMember(myMthdName, _
                                             BindingFlags.InvokeMethod _
                                               Or BindingFlags.Public _
                                               Or BindingFlags.Static, _
                                             Nothing, _
                                             Nothing, _
                                             inputValsList)) 
      Console.WriteLine("---")

      ' If you are interested in seeing the MSIL generated dynamically for the method
      ' your program generated, change to the directory where you ran the compiled
      ' code sample and type "ildasm MyDynamicAsm.dll" at the prompt. When the list
      ' of manifest contents appears, click on "MyDynamicType" and then on the name of
      ' of the method you provided during execution.
 
      myAsmBuilder.Save("MyDynamicAsm.dll") 

      Dim myMthdInfo As MethodInfo = myType.GetMethod(myMthdName)
      Console.WriteLine("Your Dynamic Method: {0};", myMthdInfo.ToString())
   End Sub 
End Class

備註

類別 MethodBuilder 可用來完整描述通用中繼語言 （CIL） 中的方法，包括名稱、屬性、簽章和方法主體。 它會配合 TypeBuilder 類別使用，以在運行時生成類別。

您可以使用反射發射來定義全域方法，並將方法定義為類型成員。 定義方法的 API 會傳回 MethodBuilder 物件。

全域方法

全域方法是使用 ModuleBuilder.DefineGlobalMethod 傳回 MethodBuilder 物件的 方法所定義。

全域方法必須是靜態的。 如果動態模組包含全域方法， ModuleBuilder.CreateGlobalFunctions 則必須先呼叫 方法，才能保存動態模組或包含動態元件，因為 Common Language Runtime 會延後修正動態模組，直到定義所有全域函式為止。

全域原生方法是使用 ModuleBuilder.DefinePInvokeMethod 方法來定義。 平台調用 （PInvoke） 方法不得宣告為抽象或虛擬。 運行時間會設定 MethodAttributes.PinvokeImpl 平台調用方法的屬性。

做為型別成員的方法

使用 TypeBuilder.DefineMethod 方法來定義為類型成員，並傳回 MethodBuilder 物件。

方法 DefineParameter 可用來設定參數的名稱和參數屬性，或傳回值的名稱和參數屬性。 ParameterBuilder這個方法傳回的物件代表參數或傳回值。 ParameterBuilder對象可用來設定封送處理、設定常數值，以及套用自定義屬性。

屬性

列舉成員 MethodAttributes 會定義動態方法的精確特性：

• 靜態方法是使用 MethodAttributes.Static 屬性來指定。
• 最後的方法（無法覆寫的方法）是使用 MethodAttributes.Final 屬性來指定。
• 虛擬方法是使用 MethodAttributes.Virtual 屬性來指定。
• 抽象方法是使用 MethodAttributes.Abstract 屬性來指定。
• 數個屬性會決定方法可見性。 請參閱 MethodAttributes 列舉項的描述。
• 實作多載運算子的方法必須設定 MethodAttributes.SpecialName 屬性。
• 完成項必須設定 MethodAttributes.SpecialName 屬性。

已知的問題

• 雖然 MethodBuilder 衍生自 MethodInfo，但 類別中 MethodInfo 定義的一些抽象方法並未在 中 MethodBuilder完全實作。 這些 MethodBuilder 方法會擲回 NotSupportedException。 例如， MethodBuilder.Invoke 方法並未完全實作。 您可以使用 Type.GetType 或 Assembly.GetType 方法來擷取封入型別，以反映這些方法。
• 支援自定義修飾詞。