ILGenerator.BeginScope Metode

Definisi

Ruang nama:

System.Reflection.Emit

Rakitan:

System.Reflection.Emit.ILGeneration.dll

Paket:

System.Reflection.Emit.ILGeneration v4.7.0

Sumber:

ILGenerator.cs

Memulai cakupan leksikal.

public:
 abstract void BeginScope();

public abstract void BeginScope ();

abstract member BeginScope : unit -> unit

Public MustOverride Sub BeginScope ()

Pengecualian

NotSupportedException

Ini ILGenerator milik .DynamicMethod

Contoh

Sampel kode berikut mengilustrasikan penggunaan BeginScope dan EndScope.

// Get the current AppDomain.
AppDomain^ myAppDomain = AppDomain::CurrentDomain;
AssemblyName^ myAssemblyName = gcnew AssemblyName;
myAssemblyName->Name = "SampleAssembly";

// Create a dynamic assembly 'myAssembly' with access mode 'Run'.
AssemblyBuilder^ myAssembly = myAppDomain->DefineDynamicAssembly( myAssemblyName, AssemblyBuilderAccess::Run );

// Create a dynamic module 'myModule' in 'myAssembly'.
ModuleBuilder^ myModule = myAssembly->DefineDynamicModule( "MyDynamicModule", true );

// Define a public class 'MyDynamicClass'.
TypeBuilder^ myTypeBuilder = myModule->DefineType( "MyDynamicClass", TypeAttributes::Public );

// Define a public string field.
FieldBuilder^ myField = myTypeBuilder->DefineField( "MyDynamicField", String::typeid, FieldAttributes::Public );

// Create the constructor.
array<Type^>^myConstructorArgs = {String::typeid};
ConstructorBuilder^ myConstructor = myTypeBuilder->DefineConstructor( MethodAttributes::Public, CallingConventions::Standard, myConstructorArgs );

// Generate IL for 'myConstructor'.
ILGenerator^ myConstructorIL = myConstructor->GetILGenerator();

// Emit the necessary opcodes.
myConstructorIL->Emit( OpCodes::Ldarg_0 );
ConstructorInfo^ mySuperConstructor = Object::typeid->GetConstructor( gcnew array<Type^>(0) );
myConstructorIL->Emit( OpCodes::Call, mySuperConstructor );
myConstructorIL->Emit( OpCodes::Ldarg_0 );
myConstructorIL->Emit( OpCodes::Ldarg_1 );
myConstructorIL->Emit( OpCodes::Stfld, myField );
myConstructorIL->Emit( OpCodes::Ret );

// Define a dynamic method named 'MyDynamicMethod'.
MethodBuilder^ myMethod = myTypeBuilder->DefineMethod( "MyDynamicMethod", MethodAttributes::Public, String::typeid, nullptr );

// Generate IL for 'myMethod'.
ILGenerator^ myMethodIL = myMethod->GetILGenerator();

// Begin the scope for a local variable.
myMethodIL->BeginScope();
LocalBuilder^ myLocalBuilder = myMethodIL->DeclareLocal( int::typeid );
Console::WriteLine( "\nTrying to access the local variable within the scope." );
Console::WriteLine( "'myLocalBuilder' type is :{0}", myLocalBuilder->LocalType );
myMethodIL->Emit( OpCodes::Ldstr, "Local value" );
myMethodIL->Emit( OpCodes::Stloc_0, myLocalBuilder );

// End the scope of 'myLocalBuilder'.
myMethodIL->EndScope();

// Access the local variable outside the scope.
Console::WriteLine( "\nTrying to access the local variable outside the scope:\n" );
myMethodIL->Emit( OpCodes::Stloc_0, myLocalBuilder );
myMethodIL->Emit( OpCodes::Ldloc_0 );
myMethodIL->Emit( OpCodes::Ret );

// Create 'MyDynamicClass' class.
Type^ myType1 = myTypeBuilder->CreateType();

// Get the current AppDomain.
AppDomain myAppDomain = AppDomain.CurrentDomain;
AssemblyName myAssemblyName = new AssemblyName();
myAssemblyName.Name = "SampleAssembly";

// Create a dynamic assembly 'myAssembly' with access mode 'Run'.
AssemblyBuilder myAssembly = myAppDomain.DefineDynamicAssembly(
                        myAssemblyName, AssemblyBuilderAccess.Run);
// Create a dynamic module 'myModule' in 'myAssembly'.
ModuleBuilder myModule=myAssembly.DefineDynamicModule("MyDynamicModule",true);
// Define a public class 'MyDynamicClass'.
TypeBuilder myTypeBuilder = myModule.DefineType("MyDynamicClass",
                                 TypeAttributes.Public);
// Define a public string field.
FieldBuilder myField = myTypeBuilder.DefineField("MyDynamicField",
                         typeof(String), FieldAttributes.Public);
// Create the constructor.
Type[] myConstructorArgs = {typeof(String)};
ConstructorBuilder myConstructor = myTypeBuilder.DefineConstructor(
   MethodAttributes.Public, CallingConventions.Standard, myConstructorArgs);

// Generate IL for 'myConstructor'.
ILGenerator myConstructorIL = myConstructor.GetILGenerator();
// Emit the necessary opcodes.
myConstructorIL.Emit(OpCodes.Ldarg_0);
ConstructorInfo mySuperConstructor = typeof(Object).GetConstructor(new Type[0]);
myConstructorIL.Emit(OpCodes.Call, mySuperConstructor);
myConstructorIL.Emit(OpCodes.Ldarg_0);
myConstructorIL.Emit(OpCodes.Ldarg_1);
myConstructorIL.Emit(OpCodes.Stfld, myField);
myConstructorIL.Emit(OpCodes.Ret);

// Define a dynamic method named 'MyDynamicMethod'.
MethodBuilder myMethod = myTypeBuilder.DefineMethod("MyDynamicMethod",
   MethodAttributes.Public, typeof(String), null);
// Generate IL for 'myMethod'.
ILGenerator myMethodIL = myMethod.GetILGenerator();

// Begin the scope for a local variable.
myMethodIL.BeginScope();

LocalBuilder myLocalBuilder = myMethodIL.DeclareLocal(typeof(int));
Console.WriteLine("\nTrying to access the local variable within the scope.");
Console.WriteLine("'myLocalBuilder' type is: {0}", myLocalBuilder.LocalType);
myMethodIL.Emit(OpCodes.Ldstr, "Local value");
myMethodIL.Emit(OpCodes.Stloc_0, myLocalBuilder);

// End the scope of 'myLocalBuilder'.
myMethodIL.EndScope();

// Access the local variable outside the scope.
Console.WriteLine("\nTrying to access the local variable outside the scope:");
myMethodIL.Emit(OpCodes.Stloc_0, myLocalBuilder);
myMethodIL.Emit(OpCodes.Ldloc_0 );
myMethodIL.Emit(OpCodes.Ret );

// Create 'MyDynamicClass' class.
Type myType1 = myTypeBuilder.CreateType();

' Get the current AppDomain.
Dim myAppDomain As AppDomain = AppDomain.CurrentDomain
Dim myAssemblyName As New AssemblyName()
myAssemblyName.Name = "SampleAssembly"

' Create a dynamic assembly 'myAssembly' with access mode 'Run'.
Dim myAssembly As AssemblyBuilder = myAppDomain.DefineDynamicAssembly(myAssemblyName, _
                                                            AssemblyBuilderAccess.Run)
' Create a dynamic module 'myModule' in 'myAssembly'.
Dim myModule As ModuleBuilder = myAssembly.DefineDynamicModule("MyDynamicModule", True)
' Define a public class 'MyDynamicClass'.
Dim myTypeBuilder As TypeBuilder = myModule.DefineType("MyDynamicClass", _
                                                               TypeAttributes.Public)
' Define a public string field.
Dim myField As FieldBuilder = myTypeBuilder.DefineField("MyDynamicField", GetType(String), _
                                                               FieldAttributes.Public)
' Create the constructor.
Dim myConstructorArgs As Type() = {GetType(String)}
Dim myConstructor As ConstructorBuilder = myTypeBuilder.DefineConstructor _
               (MethodAttributes.Public, CallingConventions.Standard, myConstructorArgs)

' Generate IL for 'myConstructor'.
Dim myConstructorIL As ILGenerator = myConstructor.GetILGenerator()
' Emit the necessary opcodes.
myConstructorIL.Emit(OpCodes.Ldarg_0)
Dim mySuperConstructor As ConstructorInfo = GetType(Object).GetConstructor(New Type() {})
myConstructorIL.Emit(OpCodes.Call, mySuperConstructor)
myConstructorIL.Emit(OpCodes.Ldarg_0)
myConstructorIL.Emit(OpCodes.Ldarg_1)
myConstructorIL.Emit(OpCodes.Stfld, myField)
myConstructorIL.Emit(OpCodes.Ret)

' Define a dynamic method named 'MyDynamicMethod'.
Dim myMethod As MethodBuilder = myTypeBuilder.DefineMethod("MyDynamicMethod", _
                        MethodAttributes.Public, GetType(String), Nothing)
' Generate IL for 'myMethod'.
Dim myMethodIL As ILGenerator = myMethod.GetILGenerator()

' Begin the scope for a local variable.
myMethodIL.BeginScope()

Dim myLocalBuilder As LocalBuilder = myMethodIL.DeclareLocal(GetType(Integer))
Console.WriteLine(ControlChars.NewLine + "Trying to access the local variable within" + _
                                                                     " the scope.")
Console.WriteLine("'myLocalBuilder' type is: {0}", myLocalBuilder.LocalType)
myMethodIL.Emit(OpCodes.Ldstr, "Local value")
myMethodIL.Emit(OpCodes.Stloc_0, myLocalBuilder)

' End the scope of 'myLocalBuilder'.
myMethodIL.EndScope()

' Access the local variable outside the scope.
Console.WriteLine(ControlChars.NewLine + "Trying to access the local variable outside " + _
                                          "the scope:")
myMethodIL.Emit(OpCodes.Stloc_0, myLocalBuilder)
myMethodIL.Emit(OpCodes.Ldloc_0)
myMethodIL.Emit(OpCodes.Ret)

' Create 'MyDynamicClass' class.
Dim myType1 As Type = myTypeBuilder.CreateType()

Keterangan

Metode ini digunakan untuk memancarkan informasi simbolis. Variabel lokal yang dideklarasikan setelah BeginScope dilingkup hingga yang sesuai EndScope dipanggil.

Jika saat ini ILGenerator dikaitkan dengan DynamicMethod objek, objek tidak mendukung informasi simbolis.