Wsrtjtyk

I have an internal method like this

void Foo(Action<DB> act)

the class DB is in the same assembly and also marked internal. I can work out how to get a methodinfo for Foo but I cannot work out how to set up the callback act in the calling code. This is what I have so far (as an added spice I want to call another internal method from inside the callback)

    var tt = eng.GetType().Assembly;

    var dd = tt.GetType("Internal.DB");

    var kk = typeof(Action<>);

    Type targs =  { dd };

    var qq = kk.MakeGenericType(targs);

    MethodInfo dynMethod = eng.GetType().GetMethod("Foo", BindingFlags.NonPublic | BindingFlags.Instance, null, new Type { qq },null);

    dynMethod.Invoke(this, new object {

        ((Action<object>)(db=>{

       MethodInfo dynMethod2 = db.GetType().GetMethod("Wiz", BindingFlags.NonPublic | BindingFlags.Instance);

        dynMethod2.Invoke(db);

    })) }); 

my problem is here (I think)

((Action<object>)(db=>{

I really need

((Action<DB>)(db=>{

but I cannot do that (DB is internal), the one with object compiles but fails at run time saying that the object is of the wrong type.

I've changed very little of your example and got code which compiles and runs to completion. Is there a chance your DB.Wiz() is throwing an exception? If not we may need more info about which runtime is giving you this issue or a more complete example. Below example properly outputs "Hello, World!"

.Net 4.6.1 Solution

ConsoleApp project, has reference to Class Library namespace Internal. I've changed your dynMethod2.Invoke() to pass an empty object as your example did not compile with one parameter to Invoke. Also removed redundant parens around your lambda expression.

private static void Main(string args)

{

    Internal.Eng eng = new Internal.Eng();



    var tt = eng.GetType().Assembly;

    var dd = tt.GetType("Internal.DB");

    var kk = typeof(Action<>);

    Type targs = { dd };



    var qq = kk.MakeGenericType(targs);



    MethodInfo dynMethod = eng.GetType().GetMethod("Foo", BindingFlags.NonPublic | BindingFlags.Instance, null, new Type { qq }, null);



    dynMethod.Invoke(eng, new object {

        (Action<object>)(db=>{

            MethodInfo dynMethod2 = db.GetType().GetMethod("Wiz", BindingFlags.NonPublic | BindingFlags.Instance);

            dynMethod2.Invoke(db, new object{ });

        })

    });

}

Class library Internal namespace.

using System;



namespace Internal

{

    public class Eng

    {

        internal void Foo(Action<DB> act) => act(new DB());

    }



    internal class DB

    {

        internal void Wiz()

        {

            Console.WriteLine("Hello, World!");

        }

    }

}

A bit hard figuring out exactly what it is you're trying to do, but if Wiz is a method of DB that accepts no parameters then I believe you're after something like this:

dynMethod.Invoke(this, new object {

    ((Action<DB>)(db=> {

        MethodInfo dynMethod2 = db.GetType().GetMethod("Wiz", BindingFlags.NonPublic | BindingFlags.Instance);

        dynMethod2.Invoke(db, null);

})) });