ILGenerator.EmitCall(OpCode, MethodInfo, Type[]) Método

Definición

Espacio de nombres:

System.Reflection.Emit

Ensamblado:

System.Reflection.Emit.ILGeneration.dll

Source:

ILGenerator.cs

Coloca una instrucción call o callvirt en la secuencia de Lenguaje Intermedio de Microsoft (MSIL) para llamar a un método varargs.

public:
 abstract void EmitCall(System::Reflection::Emit::OpCode opcode, System::Reflection::MethodInfo ^ methodInfo, cli::array <Type ^> ^ optionalParameterTypes);

public abstract void EmitCall (System.Reflection.Emit.OpCode opcode, System.Reflection.MethodInfo methodInfo, Type[]? optionalParameterTypes);

abstract member EmitCall : System.Reflection.Emit.OpCode * System.Reflection.MethodInfo * Type[] -> unit

Public MustOverride Sub EmitCall (opcode As OpCode, methodInfo As MethodInfo, optionalParameterTypes As Type())

Parámetros

opcode

OpCode

La instrucción MSIL que se emiten en la secuencia. Debe ser Call, Callvirt o Newobj.

methodInfo

MethodInfo

Método varargs al que se va a llamar.

optionalParameterTypes

Type[]

Tipos de los argumentos opcionales si se trata de un método varargs; de lo contrario, null.

Excepciones

ArgumentException

opcode no especifica una llamada de método.

ArgumentNullException

methodInfo es null.

InvalidOperationException

La convención de llamada del método no es varargs, pero se proporcionan tipos de parámetro opcionales. Esta excepción se inicia en las versiones 1.0 y 1.1 de .NET Framework. En versiones posteriores, no se inicia ninguna excepción.

Ejemplos

En el ejemplo de código siguiente se emiten dos métodos, un varargs método y un método que llama al varargs método . El EmitCall método se usa para emitir la llamada al varargs método .

using namespace System;
using namespace System::Reflection;
using namespace System::Reflection::Emit;

void main() 
{
    String^ name = "InMemory";

    AssemblyBuilder^ asmBldr = 
       AppDomain::CurrentDomain->DefineDynamicAssembly(gcnew AssemblyName(name), 
          AssemblyBuilderAccess::Run);
    ModuleBuilder^ modBldr = asmBldr->DefineDynamicModule(name); 

    TypeBuilder^ tb = modBldr->DefineType("DemoVararg");

    // Create a vararg method with no return value and one 
    // string argument. (The string argument type is the only
    // element of an array of Type objects.)
    //
    MethodBuilder^ mb1 = tb->DefineMethod("VarargMethod",
        MethodAttributes::Public | MethodAttributes::Static,
        CallingConventions::VarArgs,
        nullptr, 
        gcnew array<Type^> { String::typeid });

    ILGenerator^ il1 = mb1->GetILGenerator();

    LocalBuilder^ locAi = il1->DeclareLocal(ArgIterator::typeid);
    LocalBuilder^ locNext = il1->DeclareLocal(bool::typeid);

    Label labelCheckCondition = il1->DefineLabel();
    Label labelNext = il1->DefineLabel();

    // Load the fixed argument and print it.
    il1->Emit(OpCodes::Ldarg_0);
    il1->Emit(OpCodes::Call, Console::typeid->GetMethod("Write", 
         gcnew array<Type^> { String::typeid }));

    // Load the address of the local variable represented by
    // locAi, which will hold the ArgIterator.
    il1->Emit(OpCodes::Ldloca_S, locAi);

    // Load the address of the argument list, and call the 
    // ArgIterator constructor that takes an array of runtime
    // argument handles. 
    il1->Emit(OpCodes::Arglist);
    il1->Emit(OpCodes::Call, ArgIterator::typeid->GetConstructor(
         gcnew array<Type^> { RuntimeArgumentHandle::typeid }));

    // Enter the loop at the point where the remaining argument
    // count is tested.
    il1->Emit(OpCodes::Br_S, labelCheckCondition);

    // At the top of the loop, call GetNextArg to get the next 
    // argument from the ArgIterator. Convert the typed reference
    // to an object reference and write the object to the console.
    il1->MarkLabel(labelNext);
    il1->Emit(OpCodes::Ldloca_S, locAi);
    il1->Emit(OpCodes::Call, ArgIterator::typeid->GetMethod("GetNextArg", Type::EmptyTypes));
    il1->Emit(OpCodes::Call, TypedReference::typeid->GetMethod("ToObject"));
    il1->Emit(OpCodes::Call, Console::typeid->GetMethod("Write", 
         gcnew array<Type^> { Object::typeid }));

    il1->MarkLabel(labelCheckCondition);
    il1->Emit(OpCodes::Ldloca_S, locAi);
    il1->Emit(OpCodes::Call, ArgIterator::typeid->GetMethod("GetRemainingCount"));

    // If the remaining count is greater than zero, go to
    // the top of the loop.
    il1->Emit(OpCodes::Ldc_I4_0);
    il1->Emit(OpCodes::Cgt);
    il1->Emit(OpCodes::Stloc_1);
    il1->Emit(OpCodes::Ldloc_1);
    il1->Emit(OpCodes::Brtrue_S, labelNext);

    il1->Emit(OpCodes::Ret);

    // Create a method that contains a call to the vararg 
    // method.
    MethodBuilder^ mb2 = tb->DefineMethod("CallVarargMethod",
        MethodAttributes::Public | MethodAttributes::Static,
        CallingConventions::Standard,
        nullptr, Type::EmptyTypes);

    ILGenerator^ il2 = mb2->GetILGenerator();

    // Push arguments on the stack: one for the fixed string
    // parameter, and two for the list.
    il2->Emit(OpCodes::Ldstr, "Hello ");
    il2->Emit(OpCodes::Ldstr, "world ");
    il2->Emit(OpCodes::Ldc_I4, 2006);

    // Call the vararg method, specifying the types of the 
    // arguments in the list.
    il2->EmitCall(OpCodes::Call, mb1, 
        gcnew array<Type^> { String::typeid, int::typeid });

    il2->Emit(OpCodes::Ret);

    Type^ type = tb->CreateType();
    type->GetMethod("CallVarargMethod")->Invoke(nullptr, nullptr);
}

/* This code example produces the following output:

Hello world 2006
 */

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

class Example
{
    static void Main()
    {
        string name = "InMemory";

        AssemblyBuilder asmBldr =
           AppDomain.CurrentDomain.DefineDynamicAssembly(new AssemblyName(name),
              AssemblyBuilderAccess.Run);
        ModuleBuilder modBldr = asmBldr.DefineDynamicModule(name);

        TypeBuilder tb = modBldr.DefineType("DemoVararg");

        // Create a vararg method with no return value and one
        // string argument. (The string argument type is the only
        // element of an array of Type objects.)
        //
        MethodBuilder mb1 = tb.DefineMethod("VarargMethod",
            MethodAttributes.Public | MethodAttributes.Static,
            CallingConventions.VarArgs,
            null,
            new Type[] { typeof(string) });

        ILGenerator il1 = mb1.GetILGenerator();

        LocalBuilder locAi = il1.DeclareLocal(typeof(ArgIterator));
        LocalBuilder locNext = il1.DeclareLocal(typeof(bool));

        Label labelCheckCondition = il1.DefineLabel();
        Label labelNext = il1.DefineLabel();

        // Load the fixed argument and print it.
        il1.Emit(OpCodes.Ldarg_0);
        il1.Emit(OpCodes.Call, typeof(Console).GetMethod("Write", new Type[] { typeof(string) }));

        // Load the address of the local variable represented by
        // locAi, which will hold the ArgIterator.
        il1.Emit(OpCodes.Ldloca_S, locAi);

        // Load the address of the argument list, and call the
        // ArgIterator constructor that takes an array of runtime
        // argument handles.
        il1.Emit(OpCodes.Arglist);
        il1.Emit(OpCodes.Call, typeof(ArgIterator).GetConstructor(new Type[] { typeof(RuntimeArgumentHandle) }));

        // Enter the loop at the point where the remaining argument
        // count is tested.
        il1.Emit(OpCodes.Br_S, labelCheckCondition);

        // At the top of the loop, call GetNextArg to get the next
        // argument from the ArgIterator. Convert the typed reference
        // to an object reference and write the object to the console.
        il1.MarkLabel(labelNext);
        il1.Emit(OpCodes.Ldloca_S, locAi);
        il1.Emit(OpCodes.Call, typeof(ArgIterator).GetMethod("GetNextArg", Type.EmptyTypes));
        il1.Emit(OpCodes.Call, typeof(TypedReference).GetMethod("ToObject"));
        il1.Emit(OpCodes.Call, typeof(Console).GetMethod("Write", new Type[] { typeof(object) }));

        il1.MarkLabel(labelCheckCondition);
        il1.Emit(OpCodes.Ldloca_S, locAi);
        il1.Emit(OpCodes.Call, typeof(ArgIterator).GetMethod("GetRemainingCount"));

        // If the remaining count is greater than zero, go to
        // the top of the loop.
        il1.Emit(OpCodes.Ldc_I4_0);
        il1.Emit(OpCodes.Cgt);
        il1.Emit(OpCodes.Stloc_1);
        il1.Emit(OpCodes.Ldloc_1);
        il1.Emit(OpCodes.Brtrue_S, labelNext);

        il1.Emit(OpCodes.Ret);

        // Create a method that contains a call to the vararg
        // method.
        MethodBuilder mb2 = tb.DefineMethod("CallVarargMethod",
            MethodAttributes.Public | MethodAttributes.Static,
            CallingConventions.Standard,
            typeof(void), Type.EmptyTypes);
        ILGenerator il2 = mb2.GetILGenerator();

        // Push arguments on the stack: one for the fixed string
        // parameter, and two for the list.
        il2.Emit(OpCodes.Ldstr, "Hello ");
        il2.Emit(OpCodes.Ldstr, "world ");
        il2.Emit(OpCodes.Ldc_I4, 2006);

        // Call the vararg method, specifying the types of the
        // arguments in the list.
        il2.EmitCall(OpCodes.Call, mb1, new Type[] { typeof(string), typeof(int) });

        il2.Emit(OpCodes.Ret);

        Type type = tb.CreateType();
        type.GetMethod("CallVarargMethod").Invoke(null, null);
    }
}

/* This code example produces the following output:

Hello world 2006
 */

Imports System.Reflection
Imports System.Reflection.Emit

Class Example
    
    Shared Sub Main() 

        Dim name As String = "InMemory"
        
        Dim asmBldr As AssemblyBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly( _
            New AssemblyName(name), AssemblyBuilderAccess.Run)
        Dim modBldr As ModuleBuilder = asmBldr.DefineDynamicModule(name)
        
        Dim tb As TypeBuilder = modBldr.DefineType("DemoVararg")
        
        ' Create a vararg method with no return value and one 
        ' string argument. (The string argument type is the only
        ' element of an array of Type objects.)
        '
        Dim mb1 As MethodBuilder = tb.DefineMethod("VarargMethod", _
            MethodAttributes.Public Or MethodAttributes.Static, _
            CallingConventions.VarArgs, _
            Nothing, _
            New Type() {GetType(String)})
        
        Dim il1 As ILGenerator = mb1.GetILGenerator()
        
        Dim locAi As LocalBuilder = il1.DeclareLocal(GetType(ArgIterator))
        Dim locNext As LocalBuilder = il1.DeclareLocal(GetType(Boolean))
        
        Dim labelCheckCondition As Label = il1.DefineLabel()
        Dim labelNext As Label = il1.DefineLabel()
        
        ' Load the fixed argument and print it.
        il1.Emit(OpCodes.Ldarg_0)
        il1.Emit(OpCodes.Call, GetType(Console).GetMethod("Write", _
            New Type() {GetType(String)}))
        
        ' Load the address of the local variable represented by
        ' locAi, which will hold the ArgIterator.
        il1.Emit(OpCodes.Ldloca_S, locAi)
        
        ' Load the address of the argument list, and call the 
        ' ArgIterator constructor that takes an array of runtime
        ' argument handles. 
        il1.Emit(OpCodes.Arglist)
        il1.Emit(OpCodes.Call, GetType(ArgIterator).GetConstructor( _
            New Type() {GetType(RuntimeArgumentHandle)}))
        
        ' Enter the loop at the point where the remaining argument
        ' count is tested.
        il1.Emit(OpCodes.Br_S, labelCheckCondition)
        
        ' At the top of the loop, call GetNextArg to get the next 
        ' argument from the ArgIterator. Convert the typed reference
        ' to an object reference and write the object to the console.
        il1.MarkLabel(labelNext)
        il1.Emit(OpCodes.Ldloca_S, locAi)
        il1.Emit(OpCodes.Call, _
            GetType(ArgIterator).GetMethod("GetNextArg", Type.EmptyTypes))
        il1.Emit(OpCodes.Call, GetType(TypedReference).GetMethod("ToObject"))
        il1.Emit(OpCodes.Call, _
            GetType(Console).GetMethod("Write", New Type() {GetType(Object)}))
        
        il1.MarkLabel(labelCheckCondition)
        il1.Emit(OpCodes.Ldloca_S, locAi)
        il1.Emit(OpCodes.Call, _
            GetType(ArgIterator).GetMethod("GetRemainingCount"))
        
        ' If the remaining count is greater than zero, go to
        ' the top of the loop.
        il1.Emit(OpCodes.Ldc_I4_0)
        il1.Emit(OpCodes.Cgt)
        il1.Emit(OpCodes.Stloc_1)
        il1.Emit(OpCodes.Ldloc_1)
        il1.Emit(OpCodes.Brtrue_S, labelNext)
        
        il1.Emit(OpCodes.Ret)
        
        ' Create a method that contains a call to the vararg 
        ' method.
        Dim mb2 As MethodBuilder = tb.DefineMethod("CallVarargMethod", _
            MethodAttributes.Public Or MethodAttributes.Static, _
            CallingConventions.Standard, _
            Nothing, _
            Type.EmptyTypes)

        Dim il2 As ILGenerator = mb2.GetILGenerator()
        
        ' Push arguments on the stack: one for the fixed string
        ' parameter, and two for the list.
        il2.Emit(OpCodes.Ldstr, "Hello ")
        il2.Emit(OpCodes.Ldstr, "world ")
        il2.Emit(OpCodes.Ldc_I4, 2006)
        
        ' Call the vararg method, specifying the types of the 
        ' arguments in the list.
        il2.EmitCall(OpCodes.Call, mb1, _
            New Type() {GetType(String), GetType(Integer)})
        
        il2.Emit(OpCodes.Ret)
        
        Dim myType As Type = tb.CreateType()
        myType.GetMethod("CallVarargMethod").Invoke(Nothing, Nothing)
    
    End Sub 
End Class 

' This code example produces the following output:
'
'Hello world 2006
'

Comentarios

El EmitCall método se usa para emitir llamadas a varargs métodos porque no hay ninguna sobrecarga del Emit método que especifica los tipos de parámetro de los argumentos de variable.

Para emitir llamadas a métodos que no usan la VarArgs convención de llamada, use la sobrecarga del Emit(OpCode, MethodInfo) método .

El EmitCall método no produce una excepción cuando se especifican tipos de parámetro opcionales para un método que no varargses . InvalidProgramException se produce cuando se ejecuta la llamada.