Using SetRaiseMethod and GetRaiseMethod and invoking the method dynamically

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 The GetRaiseMethod returns null for all events declared with the event keyword as explained in the MSDN help. The documentation apparently is not as verbose as it should have been and we will work on that. The documentation around this is extremely confusing and I will personally take it as a work item to make it better. If you have any feedback on this please let me know and I will be more than glad to help you with this.

The GetRaiseMethod will return the method that was set through SetRaiseMethod if you generate a method dynamically. I have a sample below that actually demonstrates this. I have invoked the method just to demonstrate that the MethodInfo that we got was indeed right.

MSDN remarks for GetRaiseMethod:
This method returns a null reference (Nothing in Visual Basic) for events declared with the C# event keyword or the Visual Basic Event keyword. This is because the C# and Visual Basic compilers do not generate such a method.

using System;

using System.Threading;

using System.Reflection;

using System.Reflection.Emit;

public class MyApplication

{

    public delegate void MyEvent(Object temp);

    public static void Main()

    {

        // create the type

        //

        Type helloWorldClassType = CreateCallee();

        // GetRaiseMethod

        //

        EventInfo ei = helloWorldClassType.GetEvent("Click", BindingFlags.Public | BindingFlags.Instance);

        MethodInfo rm = ei.GetRaiseMethod();

        Console.WriteLine("Raise Method for event {0} is {1}", ei.Name, rm.Name);

        Console.WriteLine(helloWorldClassType.GetType().ToString());

        // Invoke the dynamic method

        //

        MethodInfo dm = helloWorldClassType.GetMethod("OnClick");

        Object o = Activator.CreateInstance(helloWorldClassType);

        // Both of them call the emitted method

        //

        dm.Invoke(o, new Object[1]);

        rm.Invoke(o, new Object[1]);

    }

  private static Type CreateCallee()

    {

        AppDomain myDomain = Thread.GetDomain();

        AssemblyName assemblyName = new AssemblyName();

        assemblyName.Name = "EmittedAssembly";

        AssemblyBuilder myAssembly = myDomain.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run);

        ModuleBuilder myModule = myAssembly.DefineDynamicModule("EmittedModule");

        TypeBuilder helloWorldClass = myModule.DefineType("HelloWorld", TypeAttributes.Public);

        MethodBuilder myMethod1 = helloWorldClass.DefineMethod("OnClick", MethodAttributes.Public, typeof(void), new Type[1] { typeof(Object) });

        ILGenerator methodIL1 = myMethod1.GetILGenerator();

        methodIL1.EmitWriteLine("This is the emitted method");

        methodIL1.Emit(OpCodes.Ret);

        EventBuilder myEvent1 = helloWorldClass.DefineEvent("Click", EventAttributes.None, typeof(MyEvent));

        myEvent1.SetRaiseMethod(myMethod1);

        Type helloWorldClassType = helloWorldClass.CreateType();

        return helloWorldClassType;

    }

}