c# - How to invoke (non virtually) the original implementation of a virtual method?

Question

I have the following situation:

In a 3rd party library (can not be modified):

class A { public virtual void M() {} }

class B : A { public override void M() {} }

In my own code:

class C : B { public override void M() {} }

From C's implementation of method M I want to call A's (but not B's!!). Can I?

Any tricks accepted, reflection included. I tried reflection already, but using the MethodInfo that I get from typeof(A) still generates a virtual call (calling C's implementation with subsequent stack overflow).

Deriving C from A is out of the question due to the complexity of reimplementing B.

Answer 1

you can generate dynamic method to make proxy that use Call (not CallVirt) instruction

        var x = new C();
        var m = typeof (A).GetMethod("M");
        var dm = new DynamicMethod("proxy",  typeof (void), new [] {typeof(C)}, typeof (C));
        var il = dm.GetILGenerator();
        il.Emit(OpCodes.Ldarg_0);
        il.Emit(OpCodes.Call, m);
        il.Emit(OpCodes.Ret);
        var action = (Action<C>)dm.CreateDelegate(typeof (Action<C>));
        action(x);