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

Definition

Namespace:

System.Reflection.Emit

Assembly:

System.Reflection.Emit.ILGeneration.dll

Quelle:

ILGenerator.cs

Fügt eine call- oder callvirt-Anweisung in den MSIL-Datenstrom (Microsoft Intermediate Language) ein, um eine varargs-Methode aufzurufen.

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())

Parameter

opcode

OpCode

Die MSIL-Anweisung, die in den Datenstrom ausgegeben werden soll. Muss Call, Callvirt oder Newobj sein.

methodInfo

MethodInfo

Ruft die varargs-Methode ab, die aufgerufen werden soll.

optionalParameterTypes

Type[]

Die Typen der optionalen Argumente, wenn die Methode eine varargs-Methode ist, andernfalls null.

Ausnahmen

ArgumentException

opcode gibt keinen Methodenaufruf an.

ArgumentNullException

methodInfo ist null.

InvalidOperationException

Die Aufrufkonvention für die Methode ist nicht varargs, aber es werden optionale Parametertypen bereitgestellt. Diese Ausnahme wird in den .NET Framework-Versionen 1.0 und 1.1 ausgelöst. In höheren Versionen wird keine Ausnahme ausgelöst.

Beispiele

Im folgenden Codebeispiel werden zwei Methoden ausgegeben: eine varargs -Methode und eine -Methode, die die varargs -Methode aufruft. Die EmitCall -Methode wird verwendet, um den Aufruf der varargs -Methode auszurufen.

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
'

Hinweise

Die EmitCall -Methode wird zum Ausgeben von Aufrufen von varargs Methoden verwendet, da keine Überladung der Emit -Methode vorhanden ist, die die Parametertypen der Variablenargumente angibt.

Verwenden Sie die Methodenüberladung, um Aufrufe von Methoden auszustrahlen, die VarArgsEmit(OpCode, MethodInfo) die Aufrufkonvention nicht verwenden.

Die EmitCall -Methode löst keine Ausnahme aus, wenn optionale Parametertypen für eine Methode angegeben werden, die nicht varargsist. InvalidProgramException wird ausgelöst, wenn der Aufruf ausgeführt wird.