This documentation is archived and is not being maintained.

AppDomain.CreateInstanceAndUnwrap Method (String, String, Object[])

Creates a new instance of the specified type. Parameters specify the assembly where the type is defined, the name of the type, and an array of activation attributes.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

Object^ CreateInstanceAndUnwrap (
	String^ assemblyName, 
	String^ typeName, 
	array<Object^>^ activationAttributes
public Object CreateInstanceAndUnwrap (
	String assemblyName, 
	String typeName, 
	Object[] activationAttributes
public function CreateInstanceAndUnwrap (
	assemblyName : String, 
	typeName : String, 
	activationAttributes : Object[]
) : Object



The display name of the assembly. See Assembly.FullName.


The fully qualified name of the requested type, including the namespace but not the assembly, as returned by the Type.FullName property.


An array containing one or more attributes that can participate in activation.

Return Value

An instance of the object specified by typeName.

Exception typeCondition


assemblyName or typeName is a null reference (Nothing in Visual Basic).


No matching public constructor was found.


typename was not found in assemblyName.


assemblyName was not found.


The caller does not have permission to call this constructor.


The caller cannot provide activation attributes for an object that does not inherit from MarshalByRefObject.


Operations are attempted on an unloaded application domain.


assemblyName is not a valid assembly.


An assembly or module was loaded twice with two different evidences.

This is a convenience method that combines CreateInstance and ObjectHandle.Unwrap. This method calls the default constructor for typeName.

See AssemblyName for the format of assemblyName. See the Type.FullName property for the format of typeName.


If you make an early-bound call to a method M of an object of type T1 that was returned by CreateInstanceAndUnwrap, and that method makes an early-bound call to a method of an object of type T2 in an assembly C other than the current assembly or the assembly containing T1, assembly C is loaded into the current application domain. This loading occurs even if the early-bound call to T1.M() was made in the body of a DynamicMethod, or in other dynamically generated code. If the current domain is the default domain, assembly C cannot be unloaded until the process ends. If the current domain later attempts to load assembly C, the load might fail.

using namespace System;
using namespace System::IO;
using namespace System::Threading;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
using namespace System::Runtime::Remoting;

ref class ADDyno
   static Type^ CreateADynamicAssembly( interior_ptr<AppDomain^> myNewDomain, String^ executableNameNoExe )
      String^ executableName = String::Concat( executableNameNoExe, ".exe" );
      AssemblyName^ myAsmName = gcnew AssemblyName;
      myAsmName->Name = executableNameNoExe;
      myAsmName->CodeBase = Environment::CurrentDirectory;
      AssemblyBuilder^ myAsmBuilder = ( *myNewDomain)->DefineDynamicAssembly( myAsmName, AssemblyBuilderAccess::RunAndSave );
      Console::WriteLine( "-- Dynamic Assembly instantiated." );
      ModuleBuilder^ myModBuilder = myAsmBuilder->DefineDynamicModule( executableNameNoExe, executableName );
      TypeBuilder^ myTypeBuilder = myModBuilder->DefineType( executableNameNoExe, TypeAttributes::Public, MarshalByRefObject::typeid );
      array<Type^>^temp0 = nullptr;
      MethodBuilder^ myFCMethod = myTypeBuilder->DefineMethod( "CountLocalFiles", static_cast<MethodAttributes>(MethodAttributes::Public | MethodAttributes::Static), nullptr, temp0 );
      MethodInfo^ currentDirGetMI = Environment::typeid->GetProperty( "CurrentDirectory" )->GetGetMethod();
      array<Type^>^temp1 = {String::typeid};
      MethodInfo^ writeLine0objMI = Console::typeid->GetMethod( "WriteLine", temp1 );
      array<Type^>^temp2 = {String::typeid,Object::typeid,Object::typeid};
      MethodInfo^ writeLine2objMI = Console::typeid->GetMethod( "WriteLine", temp2 );
      array<Type^>^temp3 = {String::typeid};
      MethodInfo^ getFilesMI = Directory::typeid->GetMethod( "GetFiles", temp3 );
      myFCMethod->InitLocals = true;
      ILGenerator^ myFCIL = myFCMethod->GetILGenerator();
      Console::WriteLine( "-- Generating MSIL method body..." );
      LocalBuilder^ v0 = myFCIL->DeclareLocal( String::typeid );
      LocalBuilder^ v1 = myFCIL->DeclareLocal( int::typeid );
      LocalBuilder^ v2 = myFCIL->DeclareLocal( String::typeid );
      LocalBuilder^ v3 = myFCIL->DeclareLocal( array<String^>::typeid );
      Label evalForEachLabel = myFCIL->DefineLabel();
      Label topOfForEachLabel = myFCIL->DefineLabel();

      // Build the method body.
      myFCIL->EmitCall( OpCodes::Call, currentDirGetMI, nullptr );
      myFCIL->Emit( OpCodes::Stloc_S, v0 );
      myFCIL->Emit( OpCodes::Ldc_I4_0 );
      myFCIL->Emit( OpCodes::Stloc_S, v1 );
      myFCIL->Emit( OpCodes::Ldstr, "---" );
      myFCIL->EmitCall( OpCodes::Call, writeLine0objMI, nullptr );
      myFCIL->Emit( OpCodes::Ldloc_S, v0 );
      myFCIL->EmitCall( OpCodes::Call, getFilesMI, nullptr );
      myFCIL->Emit( OpCodes::Stloc_S, v3 );
      myFCIL->Emit( OpCodes::Br_S, evalForEachLabel );

      // foreach loop starts here.
      myFCIL->MarkLabel( topOfForEachLabel );

      // Load array of strings and index, store value at index for output.
      myFCIL->Emit( OpCodes::Ldloc_S, v3 );
      myFCIL->Emit( OpCodes::Ldloc_S, v1 );
      myFCIL->Emit( OpCodes::Ldelem_Ref );
      myFCIL->Emit( OpCodes::Stloc_S, v2 );
      myFCIL->Emit( OpCodes::Ldloc_S, v2 );
      myFCIL->EmitCall( OpCodes::Call, writeLine0objMI, nullptr );

      // Increment counter by one.
      myFCIL->Emit( OpCodes::Ldloc_S, v1 );
      myFCIL->Emit( OpCodes::Ldc_I4_1 );
      myFCIL->Emit( OpCodes::Add );
      myFCIL->Emit( OpCodes::Stloc_S, v1 );

      // Determine if end of file list array has been reached.
      myFCIL->MarkLabel( evalForEachLabel );
      myFCIL->Emit( OpCodes::Ldloc_S, v1 );
      myFCIL->Emit( OpCodes::Ldloc_S, v3 );
      myFCIL->Emit( OpCodes::Ldlen );
      myFCIL->Emit( OpCodes::Conv_I4 );
      myFCIL->Emit( OpCodes::Blt_S, topOfForEachLabel );

      //foreach loop end here.
      myFCIL->Emit( OpCodes::Ldstr, "---" );
      myFCIL->EmitCall( OpCodes::Call, writeLine0objMI, nullptr );
      myFCIL->Emit( OpCodes::Ldstr, "There are {0} files in {1}." );
      myFCIL->Emit( OpCodes::Ldloc_S, v1 );
      myFCIL->Emit( OpCodes::Box, int::typeid );
      myFCIL->Emit( OpCodes::Ldloc_S, v0 );
      myFCIL->EmitCall( OpCodes::Call, writeLine2objMI, nullptr );
      myFCIL->Emit( OpCodes::Ret );
      Type^ myType = myTypeBuilder->CreateType();
      myAsmBuilder->SetEntryPoint( myFCMethod );
      myAsmBuilder->Save( executableName );
      Console::WriteLine( "-- Method generated, type completed, and assembly saved to disk." );
      return myType;

int main()
   String^ domainDir;
   String^ executableName = nullptr;
   Console::Write( "Enter a name for the file counting assembly: " );
   String^ executableNameNoExe = Console::ReadLine();
   executableName = String::Concat( executableNameNoExe, ".exe" );
   Console::WriteLine( "---" );
   domainDir = Environment::CurrentDirectory;
   AppDomain^ curDomain = Thread::GetDomain();

   // Create a new AppDomain, with the current directory as the base.
   Console::WriteLine( "Current Directory: {0}", Environment::CurrentDirectory );
   AppDomainSetup^ mySetupInfo = gcnew AppDomainSetup;
   mySetupInfo->ApplicationBase = domainDir;
   mySetupInfo->ApplicationName = executableNameNoExe;
   mySetupInfo->LoaderOptimization = LoaderOptimization::SingleDomain;
   AppDomain^ myDomain = AppDomain::CreateDomain( executableNameNoExe, nullptr, mySetupInfo );
   Console::WriteLine( "Creating a new AppDomain '{0}'...", executableNameNoExe );
   Console::WriteLine( "-- Base Directory = '{0}'", myDomain->BaseDirectory );
   Console::WriteLine( "-- Shadow Copy? = '{0}'", myDomain->ShadowCopyFiles );
   Console::WriteLine( "---" );
   Type^ myFCType = ADDyno::CreateADynamicAssembly(  &curDomain, executableNameNoExe );
   Console::WriteLine( "Loading '{0}' from '{1}'...", executableName, myDomain->BaseDirectory );
   BindingFlags bFlags = static_cast<BindingFlags>(BindingFlags::Public | BindingFlags::CreateInstance | BindingFlags::Instance);
   Object^ myObjInstance = myDomain->CreateInstanceAndUnwrap( executableNameNoExe, executableNameNoExe, false, bFlags, nullptr, nullptr, nullptr, nullptr, nullptr );
   Console::WriteLine( "Executing method 'CountLocalFiles' in {0}...", myObjInstance );
   array<Object^>^temp4 = nullptr;
   myFCType->InvokeMember( "CountLocalFiles", BindingFlags::InvokeMethod, nullptr, myObjInstance, temp4 );

import System.*;
import System.IO.*;
import System.Threading.*;
import System.Reflection.*;
import System.Reflection.Emit.*;
import System.Runtime.Remoting.*;

class ADDyno
    public static Type CreateADynamicAssembly(AppDomain myNewDomain, 
        String executableNameNoExe) 
        String executableName = executableNameNoExe + ".exe";
        AssemblyName myAsmName =  new AssemblyName();

        AssemblyBuilder myAsmBuilder = 
        Console.WriteLine("-- Dynamic Assembly instantiated.");

        ModuleBuilder myModBuilder = 

        TypeBuilder myTypeBuilder = myModBuilder.DefineType(executableNameNoExe,
            TypeAttributes.Public, MarshalByRefObject.class.ToType());

        MethodBuilder myFCMethod = myTypeBuilder.DefineMethod("CountLocalFiles", 
            MethodAttributes.Public | MethodAttributes.Static, null, 
            new Type[]{});

        MethodInfo currentDirGetMI = Environment.class.ToType().
        MethodInfo writeLine0ObjMI = Console.class.ToType().
            GetMethod("WriteLine", new Type[]{String.class.ToType()});
        MethodInfo writeLine2ObjMI = Console.class.ToType().
            GetMethod("WriteLine", new Type[]{String.class.ToType(), 
            Object.class.ToType(), Object.class.ToType()});
        MethodInfo getFilesMI = Directory.class.ToType().GetMethod("GetFiles", 
            new Type[]{String.class.ToType()});

        ILGenerator myFCIL = myFCMethod.GetILGenerator();

        Console.WriteLine("-- Generating MSIL method body...");
        LocalBuilder v0 = myFCIL.DeclareLocal(String.class.ToType());
        LocalBuilder v1 = myFCIL.DeclareLocal(int.class.ToType());
        LocalBuilder v2 = myFCIL.DeclareLocal(String.class.ToType());
        LocalBuilder v3 = myFCIL.DeclareLocal(String[].class.ToType());

        Label evalForEachLabel = myFCIL.DefineLabel();
        Label topOfForEachLabel = myFCIL.DefineLabel();

        // Build the method body.
        myFCIL.EmitCall(OpCodes.Call, currentDirGetMI, null);
        myFCIL.Emit(OpCodes.Stloc_S, v0);
        myFCIL.Emit(OpCodes.Stloc_S, v1);
        myFCIL.Emit(OpCodes.Ldstr, "---");
        myFCIL.EmitCall(OpCodes.Call, writeLine0ObjMI, null);
        myFCIL.Emit(OpCodes.Ldloc_S, v0);
        myFCIL.EmitCall(OpCodes.Call, getFilesMI, null);
        myFCIL.Emit(OpCodes.Stloc_S, v3);

        myFCIL.Emit(OpCodes.Br_S, evalForEachLabel);

        // foreach loop starts here.

        // Load array of strings and index, store value at index for output.
        myFCIL.Emit(OpCodes.Ldloc_S, v3);
        myFCIL.Emit(OpCodes.Ldloc_S, v1);
        myFCIL.Emit(OpCodes.Stloc_S, v2);

        myFCIL.Emit(OpCodes.Ldloc_S, v2);
        myFCIL.EmitCall(OpCodes.Call, writeLine0ObjMI, null);

        // Increment counter by one.
        myFCIL.Emit(OpCodes.Ldloc_S, v1);
        myFCIL.Emit(OpCodes.Stloc_S, v1);

        // Determine if end of file list array has been reached.
        myFCIL.Emit(OpCodes.Ldloc_S, v1);
        myFCIL.Emit(OpCodes.Ldloc_S, v3);
        myFCIL.Emit(OpCodes.Blt_S, topOfForEachLabel);
        //foreach loop end here.

        myFCIL.Emit(OpCodes.Ldstr, "---");
        myFCIL.EmitCall(OpCodes.Call, writeLine0ObjMI, null);
        myFCIL.Emit(OpCodes.Ldstr, "There are {0} files in {1}.");
        myFCIL.Emit(OpCodes.Ldloc_S, v1);
        myFCIL.Emit(OpCodes.Box, int.class.ToType());
        myFCIL.Emit(OpCodes.Ldloc_S, v0);
        myFCIL.EmitCall(OpCodes.Call, writeLine2ObjMI, null);


        Type myType = myTypeBuilder.CreateType();

        Console.WriteLine("-- Method generated, type completed, "
            + "and assembly saved to disk.");

        return myType;
    } //CreateADynamicAssembly

    public static void main(String[] args)
        String executableName = null;
        String domainDir;

        Console.Write("Enter a name for the file counting assembly: ");
        String executableNameNoExe = Console.ReadLine();
        executableName = executableNameNoExe + ".exe";

        domainDir = Environment.get_CurrentDirectory();
        AppDomain curDomain = System.Threading.Thread.GetDomain();

        // Create a new AppDomain, with the current directory as the base.
        Console.WriteLine("Current Directory: {0}", 
        AppDomainSetup mySetupInfo =  new AppDomainSetup();

        AppDomain myDomain = AppDomain.CreateDomain(executableNameNoExe, null, 

        Console.WriteLine("Creating a new AppDomain '{0}'...", 
        Console.WriteLine("-- Base Directory = '{0}'", myDomain.get_BaseDirectory());
        Console.WriteLine("-- Shadow Copy? = '{0}'", 

        Type myFCType = CreateADynamicAssembly(curDomain, executableNameNoExe);
        Console.WriteLine("Loading '{0}' from '{1}'...", executableName, 

        BindingFlags bFlags = BindingFlags.Public | BindingFlags.CreateInstance 
            | BindingFlags.Instance;

        Object myObjInstance = 
            executableNameNoExe, false, bFlags, null, null, null, null, null);

        Console.WriteLine("Executing method 'CountLocalFiles' in {0}...", 

        myFCType.InvokeMember("CountLocalFiles", BindingFlags.InvokeMethod, 
            null, myObjInstance, new Object[]{});
   } //main
} //ADDyno 

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0