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MethodBuilder Class

Defines and represents a method (or constructor) on a dynamic class.

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

[HostProtectionAttribute(SecurityAction::LinkDemand, MayLeakOnAbort = true)]
public ref class MethodBuilder sealed : public MethodInfo, 


The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: MayLeakOnAbort. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

MethodBuilder is used to fully describe a method in Microsoft intermediate language (MSIL), including the name, attributes, signature, and method body. It is used in conjunction with the TypeBuilder class to create classes at runtime.

An example using the MethodBuilder class to create a method within a dynamic type is provided below.

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

void AddMethodDynamically( TypeBuilder^ myTypeBld, 
                           String^ mthdName, 
                           array<Type^>^ mthdParams, 
                           Type^ returnType, 
                           String^ mthdAction )
   MethodBuilder^ myMthdBld = myTypeBld->DefineMethod( mthdName, static_cast<MethodAttributes>(MethodAttributes::Public | MethodAttributes::Static), returnType, mthdParams );
   ILGenerator^ ILOut = myMthdBld->GetILGenerator();
   int numParams = mthdParams->Length;
   for ( Byte x = 0; x < numParams; x++ )
      ILOut->Emit( OpCodes::Ldarg_S, x );

   if ( numParams > 1 )
      for ( int y = 0; y < (numParams - 1); y++ )
         if ( mthdAction->Equals( "A" ) )
                  ILOut->Emit( OpCodes::Add );
         if ( mthdAction->Equals( "M" ) )
                  ILOut->Emit( OpCodes::Mul );
                  ILOut->Emit( OpCodes::Add );


   ILOut->Emit( OpCodes::Ret );

void main()
   AppDomain^ myDomain = AppDomain::CurrentDomain;
   AssemblyName^ asmName = gcnew AssemblyName;
   asmName->Name = "MyDynamicAsm";
   AssemblyBuilder^ myAsmBuilder = myDomain->DefineDynamicAssembly( asmName, 
                                                                    AssemblyBuilderAccess::RunAndSave );
   ModuleBuilder^ myModule = myAsmBuilder->DefineDynamicModule( "MyDynamicAsm", 
                                                                "MyDynamicAsm.dll" );
   TypeBuilder^ myTypeBld = myModule->DefineType( "MyDynamicType", 
                                                  TypeAttributes::Public );

   // Get info from the user to build the method dynamically.
   Console::WriteLine( "Let's build a simple method dynamically!" );
   Console::WriteLine( "Please enter a few numbers, separated by spaces." );
   String^ inputNums = Console::ReadLine();
   Console::Write( "Do you want to [A]dd (default) or [M]ultiply these numbers? " );
   String^ myMthdAction = Console::ReadLine()->ToUpper();
   Console::Write( "Lastly, what do you want to name your new dynamic method? " );
   String^ myMthdName = Console::ReadLine();

   // Process inputNums into an array and create a corresponding Type array 
   int index = 0;
   array<String^>^inputNumsList = inputNums->Split();
   array<Type^>^myMthdParams = gcnew array<Type^>(inputNumsList->Length);
   array<Object^>^inputValsList = gcnew array<Object^>(inputNumsList->Length);
   for each (String^ inputNum in inputNumsList)
      inputValsList[ index ] = Convert::ToInt32( inputNum );
      myMthdParams[ index ] = int::typeid;

   // Now, call the method building method with the parameters, passing the 
   // TypeBuilder by reference.
   AddMethodDynamically( myTypeBld, 
                         myMthdAction );
   Type^ myType = myTypeBld->CreateType();

   Console::WriteLine( "---" );
   Console::WriteLine( "The result of {0} the inputted values is: {1}", 
                       ((myMthdAction->Equals( "M" )) ? "multiplying" : "adding"), 
                       myType->InvokeMember( myMthdName, 
                                             BindingFlags::InvokeMethod | BindingFlags::Public | BindingFlags::Static, 
                       inputValsList ) );
   Console::WriteLine( "---" );

   // Let's take a look at the method we created. 
   // If you are interested in seeing the MSIL generated dynamically for the method 
   // your program generated, change to the directory where you ran the compiled 
   // code sample and type "ildasm MyDynamicAsm.dll" at the prompt. When the list
   // of manifest contents appears, click on "MyDynamicType" and then on the name of
   // of the method you provided during execution.

   myAsmBuilder->Save( "MyDynamicAsm.dll" );

   MethodInfo^ myMthdInfo = myType->GetMethod( myMthdName );
   Console::WriteLine( "Your Dynamic Method: {0};", myMthdInfo );

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0