MethodBuilder 类

定义

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

public ref class MethodBuilder sealed : 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

public sealed class MethodBuilder : System.Reflection.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

type MethodBuilder = class
    inherit MethodInfo

Public NotInheritable Class MethodBuilder
Inherits MethodInfo
Implements _MethodBuilder

Public NotInheritable Class MethodBuilder
Inherits MethodInfo

继承

Object

MemberInfo

MethodBase

MethodInfo

MethodBuilder

属性

ClassInterfaceAttribute ComVisibleAttribute

实现

_MethodBuilder

示例

以下示例使用 MethodBuilder 类在动态类型中创建方法。

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

注解

有关此 API 的详细信息，请参阅 MethodBuilder 的补充 API 说明。