MethodBuilder Clase

Definición

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

Herencia

Object

MemberInfo

MethodBase

MethodInfo

MethodBuilder

Atributos

ClassInterfaceAttribute ComVisibleAttribute

Implementaciones

_MethodBuilder

Ejemplos

En el ejemplo siguiente se usa la MethodBuilder clase para crear un método dentro de un tipo dinámico.

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

Comentarios

La MethodBuilder clase se usa para describir completamente un método en lenguaje intermedio común (CIL), incluidos el nombre, los atributos, la firma y el cuerpo del método. Se usa junto con la TypeBuilder clase para crear clases en tiempo de ejecución.

Puede usar la emisión de reflexión para definir métodos globales y definir métodos como miembros de tipo. Las API que definen los métodos devuelven MethodBuilder objetos.

Métodos globales

Un método global se define mediante el ModuleBuilder.DefineGlobalMethod método , que devuelve un MethodBuilder objeto .

Los métodos globales deben ser estáticos. Si un módulo dinámico contiene métodos globales, se debe llamar al método ModuleBuilder.CreateGlobalFunctions antes de conservar el módulo dinámico o el ensamblado dinámico contenedor porque el Common Language Runtime pospone la corrección del módulo dinámico hasta que se hayan definido todas las funciones globales.

Un método nativo global se define mediante el ModuleBuilder.DefinePInvokeMethod método . Los métodos de invocación de plataforma (PInvoke) no deben declararse abstractos ni virtuales. El tiempo de ejecución establece el MethodAttributes.PinvokeImpl atributo para un método de invocación de plataforma.

Métodos como miembros de tipos

Un método se define como un miembro de tipo mediante el TypeBuilder.DefineMethod método , que devuelve un MethodBuilder objeto .

El DefineParameter método se usa para establecer los atributos name y parameter de un parámetro o del valor devuelto. El ParameterBuilder objeto devuelto por este método representa un parámetro o el valor devuelto. El ParameterBuilder objeto se puede usar para establecer la serialización, para establecer el valor constante y para aplicar atributos personalizados.

Attributes

Los miembros de la MethodAttributes enumeración definen el carácter preciso de un método dinámico:

• Los métodos estáticos se especifican mediante el MethodAttributes.Static atributo .
• Los métodos finales (métodos que no se pueden invalidar) se especifican mediante el MethodAttributes.Final atributo .
• Los métodos virtuales se especifican mediante el MethodAttributes.Virtual atributo .
• Los métodos abstractos se especifican mediante el MethodAttributes.Abstract atributo .
• Varios atributos determinan la visibilidad del método. Consulte la descripción de la enumeración MethodAttributes.
• Los métodos que implementan operadores sobrecargados deben establecer el MethodAttributes.SpecialName atributo .
• Los finalizadores deben establecer el MethodAttributes.SpecialName atributo .

Problemas conocidos

• Aunque MethodBuilder se deriva de MethodInfo, algunos de los métodos abstractos definidos en la MethodInfo clase no se implementan completamente en MethodBuilder. Estos métodos MethodBuilder lanzan la excepción NotSupportedException. Por ejemplo, el MethodBuilder.Invoke método no está totalmente implementado. Puede reflexionar sobre estos métodos recuperando el tipo envolvente mediante el método Type.GetType o Assembly.GetType.
• Se admiten modificadores personalizados.