ParameterBuilder Clase

Definición

Espacio de nombres:

System.Reflection.Emit

Ensamblado:

mscorlib.dll

Crea o asocia información de parámetros.

public ref class ParameterBuilder : System::Runtime::InteropServices::_ParameterBuilder

[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Runtime.InteropServices.ComVisible(true)]
public class ParameterBuilder : System.Runtime.InteropServices._ParameterBuilder

[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type ParameterBuilder = class
    interface _ParameterBuilder

Public Class ParameterBuilder
Implements _ParameterBuilder

Herencia

Object

ParameterBuilder

Atributos

ClassInterfaceAttribute ComVisibleAttribute

Implementaciones

_ParameterBuilder

Ejemplos

En el ejemplo siguiente se muestra cómo crear un método dinámico con un parámetro pasado por referencia mediante ParameterBuilder.

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

class ParamBuilderDemo

{

   public static Type BuildCustomerDataType()
   {

    AppDomain myDomain = Thread.GetDomain();
    AssemblyName myAsmName = new AssemblyName();
    myAsmName.Name = "MyDynamicAssembly";

    AssemblyBuilder myAsmBuilder = myDomain.DefineDynamicAssembly(myAsmName,
                        AssemblyBuilderAccess.Run);

    ModuleBuilder myModBuilder = myAsmBuilder.DefineDynamicModule("MyMod");

    TypeBuilder myTypeBuilder = myModBuilder.DefineType("CustomerData",
                        TypeAttributes.Public);

    FieldBuilder customerNameBldr = myTypeBuilder.DefineField("customerName",
                            typeof(string),
                            FieldAttributes.Private);
    FieldBuilder acctIDBldr = myTypeBuilder.DefineField("acctID",
                            typeof(string),
                            FieldAttributes.Private);
    FieldBuilder balanceAmtBldr = myTypeBuilder.DefineField("balanceAmt",
                            typeof(double),
                            FieldAttributes.Private);
                                
    ConstructorBuilder myCtorBuilder = myTypeBuilder.DefineConstructor(
                            MethodAttributes.Public,
                            CallingConventions.HasThis,
                            new Type[] { typeof(string),
                                     typeof(string),
                                     typeof(double) });

    ILGenerator ctorIL = myCtorBuilder.GetILGenerator();

    Type objType = Type.GetType("System.Object");
        ConstructorInfo objCtor = objType.GetConstructor(new Type[] {});

    ctorIL.Emit(OpCodes.Ldarg_0);
    ctorIL.Emit(OpCodes.Call, objCtor);

    ctorIL.Emit(OpCodes.Ldarg_0);
    ctorIL.Emit(OpCodes.Ldarg_1);
    ctorIL.Emit(OpCodes.Stfld, customerNameBldr);

    ctorIL.Emit(OpCodes.Ldarg_0);
    ctorIL.Emit(OpCodes.Ldarg_2);
    ctorIL.Emit(OpCodes.Stfld, acctIDBldr);

    ctorIL.Emit(OpCodes.Ldarg_0);
    ctorIL.Emit(OpCodes.Ldarg_3);
    ctorIL.Emit(OpCodes.Stfld, balanceAmtBldr);

    ctorIL.Emit(OpCodes.Ret);

    // This method will take an amount from a static pool and add it to the balance.

    // Note that we are passing the first parameter, fundsPool, by reference. Therefore,
    // we need to inform the MethodBuilder to expect a ref, by declaring the first
    // parameter's type to be System.Double& (a reference to a double).

    MethodBuilder myMthdBuilder = myTypeBuilder.DefineMethod("AddFundsFromPool",
                        MethodAttributes.Public,
                        typeof(double),
                        new Type[] { Type.GetType("System.Double&"),
                                 typeof(double) });

    ParameterBuilder poolRefBuilder = myMthdBuilder.DefineParameter(1,
                        ParameterAttributes.Out,
                        "fundsPool");

    ParameterBuilder amountFromPoolBuilder = myMthdBuilder.DefineParameter(2,
                        ParameterAttributes.In,
                            "amountFromPool");

    ILGenerator mthdIL = myMthdBuilder.GetILGenerator();

    mthdIL.Emit(OpCodes.Ldarg_1);
    mthdIL.Emit(OpCodes.Ldarg_1);
    mthdIL.Emit(OpCodes.Ldind_R8);
    mthdIL.Emit(OpCodes.Ldarg_2);
    mthdIL.Emit(OpCodes.Sub);

    mthdIL.Emit(OpCodes.Stind_R8);

    mthdIL.Emit(OpCodes.Ldarg_0);
    mthdIL.Emit(OpCodes.Ldarg_0);
    mthdIL.Emit(OpCodes.Ldfld, balanceAmtBldr);
    mthdIL.Emit(OpCodes.Ldarg_2);
    mthdIL.Emit(OpCodes.Add);

    mthdIL.Emit(OpCodes.Stfld, balanceAmtBldr);

    mthdIL.Emit(OpCodes.Ldarg_0);
    mthdIL.Emit(OpCodes.Ldfld, balanceAmtBldr);
    mthdIL.Emit(OpCodes.Ret);

    return myTypeBuilder.CreateType();
   }

   public static void Main()
   {
    Type custType = null;
    object custObj = null;

    Type[] custArgTypes = new Type[] {typeof(string), typeof(string), typeof(double)};
    
    // Call the method to build our dynamic class.

    custType = BuildCustomerDataType();

    Console.WriteLine("---");

    ConstructorInfo myCustCtor = custType.GetConstructor(custArgTypes);
    double initialBalance = 100.00;
    custObj = myCustCtor.Invoke(new object[] { "Joe Consumer",
                           "5678-XYZ",
                           initialBalance });

    MemberInfo[] myMemberInfo = custType.GetMember("AddFundsFromPool");

    double thePool = 1000.00;
    Console.WriteLine("The pool is currently ${0}", thePool);
    Console.WriteLine("The original balance of the account instance is ${0}",
                            initialBalance);

    double amountFromPool = 50.00;
    Console.WriteLine("The amount to be subtracted from the pool and added " +
              "to the account is ${0}", amountFromPool);
    
    Console.WriteLine("---");
    Console.WriteLine("Calling {0} ...", myMemberInfo[0].ToString());
    Console.WriteLine("---");

    object[] passMe = new object[] { thePool, amountFromPool };
    Console.WriteLine("The new balance in the account instance is ${0}",
                    custType.InvokeMember("AddFundsFromPool",
                    BindingFlags.InvokeMethod,
                    null, custObj, passMe));
    thePool = (double)passMe[0];
    Console.WriteLine("The new amount in the pool is ${0}", thePool);
   }
}

Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit

 _

Class ParamBuilderDemo
   
   Public Shared Function BuildCustomerDataType() As Type
      
      Dim myDomain As AppDomain = Thread.GetDomain()
      Dim myAsmName As New AssemblyName()
      myAsmName.Name = "MyDynamicAssembly"
      
      Dim myAsmBuilder As AssemblyBuilder = myDomain.DefineDynamicAssembly(myAsmName, _
                        AssemblyBuilderAccess.Run)
      
      Dim myModBuilder As ModuleBuilder = myAsmBuilder.DefineDynamicModule("MyMod")
      
      Dim myTypeBuilder As TypeBuilder = myModBuilder.DefineType("CustomerData", TypeAttributes.Public)
      
      Dim customerNameBldr As FieldBuilder = myTypeBuilder.DefineField("customerName", _
                                GetType(String), _
                                FieldAttributes.Private)
      Dim acctIDBldr As FieldBuilder = myTypeBuilder.DefineField("acctID", _
                                GetType(String), _
                                FieldAttributes.Private)
      Dim balanceAmtBldr As FieldBuilder = myTypeBuilder.DefineField("balanceAmt", _
                                GetType(Double), _
                                FieldAttributes.Private)
      
      Dim myCtorBuilder As ConstructorBuilder = myTypeBuilder.DefineConstructor(MethodAttributes.Public, _
                                CallingConventions.HasThis, _
                                New Type() {GetType(String), _
                                        GetType(String), _
                                        GetType(Double)})
      
      
      Dim ctorIL As ILGenerator = myCtorBuilder.GetILGenerator()
      
      Dim objType As Type = Type.GetType("System.Object")
      Dim objCtor As ConstructorInfo = objType.GetConstructor(New Type(){})
      
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Call, objCtor)
      
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Ldarg_1)
      ctorIL.Emit(OpCodes.Stfld, customerNameBldr)
      
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Ldarg_2)
      ctorIL.Emit(OpCodes.Stfld, acctIDBldr)
      
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Ldarg_3)
      ctorIL.Emit(OpCodes.Stfld, balanceAmtBldr)
      
      ctorIL.Emit(OpCodes.Ret)
      
      ' This method will take an amount from a static pool and add it to the balance.
      ' Note that we are passing the first parameter, fundsPool, by reference. Therefore,
      ' we need to inform the MethodBuilder to expect a ref, by declaring the first
      ' parameter's type to be System.Double& (a reference to a double).

      Dim myMthdBuilder As MethodBuilder = myTypeBuilder.DefineMethod("AddFundsFromPool", _
                                MethodAttributes.Public, _
                                GetType(Double), _
                                New Type() {Type.GetType("System.Double&"), _
                                         GetType(Double)})
      
      Dim poolRefBuilder As ParameterBuilder = myMthdBuilder.DefineParameter(1, _
                            ParameterAttributes.Out, "fundsPool")
      
      Dim amountFromPoolBuilder As ParameterBuilder = myMthdBuilder.DefineParameter(2, _
                            ParameterAttributes.In, "amountFromPool")
      
      Dim mthdIL As ILGenerator = myMthdBuilder.GetILGenerator()
      
      mthdIL.Emit(OpCodes.Ldarg_1)
      mthdIL.Emit(OpCodes.Ldarg_1)
      mthdIL.Emit(OpCodes.Ldind_R8)
      mthdIL.Emit(OpCodes.Ldarg_2)
      mthdIL.Emit(OpCodes.Sub)
      
      mthdIL.Emit(OpCodes.Stind_R8)
      
      mthdIL.Emit(OpCodes.Ldarg_0)
      mthdIL.Emit(OpCodes.Ldarg_0)
      mthdIL.Emit(OpCodes.Ldfld, balanceAmtBldr)
      mthdIL.Emit(OpCodes.Ldarg_2)
      mthdIL.Emit(OpCodes.Add)
      
      mthdIL.Emit(OpCodes.Stfld, balanceAmtBldr)
      
      mthdIL.Emit(OpCodes.Ldarg_0)
      mthdIL.Emit(OpCodes.Ldfld, balanceAmtBldr)
      mthdIL.Emit(OpCodes.Ret)
      
      Return myTypeBuilder.CreateType()

   End Function 'BuildCustomerDataType
    
   
   Public Shared Sub Main()

      Dim custType As Type = Nothing
      Dim custObj As Object = Nothing
      
      Dim custArgTypes() As Type = {GetType(String), GetType(String), GetType(Double)}
      
      ' Call the method to build our dynamic class.
      custType = BuildCustomerDataType()
      
      Console.WriteLine("---")
      
      Dim myCustCtor As ConstructorInfo = custType.GetConstructor(custArgTypes)
      Dim initialBalance As Double = 100.0
      custObj = myCustCtor.Invoke(New Object() {"Joe Consumer", "5678-XYZ", initialBalance})
      
      Dim myMemberInfo As MemberInfo() = custType.GetMember("AddFundsFromPool")
      
      
      Dim thePool As Double = 1000.0
      Console.WriteLine("The pool is currently ${0}", thePool)
      Console.WriteLine("The original balance of the account instance is ${0}", initialBalance)
      
      Dim amountFromPool As Double = 50.0
      Console.WriteLine("The amount to be subtracted from the pool and added " & _
            "to the account is ${0}", amountFromPool)
      
      Console.WriteLine("---")
      Console.WriteLine("Calling {0} ...", myMemberInfo(0).ToString())
      Console.WriteLine("---")
      
      Dim passMe() As Object = {thePool, amountFromPool}
      Console.WriteLine("The new balance in the account instance is ${0}", _
                custType.InvokeMember("AddFundsFromPool", _
                BindingFlags.InvokeMethod, Nothing, custObj, passMe))
      thePool = CDbl(passMe(0))
      Console.WriteLine("The new amount in the pool is ${0}", thePool)

   End Sub

End Class

Comentarios

Los atributos de parámetro deben ser coherentes con la firma del método. Si especifica Out atributos para un parámetro, debe asegurarse de que el tipo de ese parámetro de método es un ByRef tipo.

Algunos atributos /> de con parámetros viables para que el lenguaje intermedio (MSIL) de Microsoft funcione correctamente en tiempo de ejecución. Por ejemplo, si define un ParameterBuilder elemento con ParameterAttributes.Out para el parámetro 1 de , MethodBuilderel parámetro 1 de MethodBuilder debe ser una referencia como Type.GetType("System.String&"), en lugar de Type.GetType("System.String").

Propiedades

Nombre	Description
Attributes	Recupera los atributos de este parámetro.
IsIn	Recupera si se trata de un parámetro de entrada.
IsOptional	Recupera si este parámetro es opcional.
IsOut	Recupera si este parámetro es un parámetro de salida.
Name	Recupera el nombre de este parámetro.
Position	Recupera la posición de firma de este parámetro.

Métodos

Nombre	Description
Equals(Object)	Determina si el objeto especificado es igual al objeto actual. (Heredado de Object)
GetHashCode()	Actúa como la función hash predeterminada. (Heredado de Object)
GetToken()	Recupera el token de este parámetro.
GetType()	Obtiene el Type de la instancia actual. (Heredado de Object)
MemberwiseClone()	Crea una copia superficial del Objectactual. (Heredado de Object)
SetConstant(Object)	Establece el valor predeterminado del parámetro .
SetCustomAttribute(ConstructorInfo, Byte[])	Establezca un atributo personalizado mediante un blob de atributo personalizado especificado.
SetCustomAttribute(CustomAttributeBuilder)	Establezca un atributo personalizado mediante un generador de atributos personalizados.
SetMarshal(UnmanagedMarshal)	Obsoletos. Especifica la serialización de este parámetro.
ToString()	Devuelve una cadena que representa el objeto actual. (Heredado de Object)

Implementaciones de interfaz explícitas

Nombre	Description
_ParameterBuilder.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)	Asigna un conjunto de nombres a un conjunto correspondiente de identificadores de envío.
_ParameterBuilder.GetTypeInfo(UInt32, UInt32, IntPtr)	Recupera la información de tipo de un objeto, que se puede usar después para obtener la información de tipo de una interfaz.
_ParameterBuilder.GetTypeInfoCount(UInt32)	Recupera el número de interfaces de información de tipo que proporciona un objeto (0 ó 1).
_ParameterBuilder.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)	Proporciona acceso a propiedades y métodos expuestos por un objeto .