How to use generics with the current type

Question

I have this base class:

public abstract class Parent {
    public void DoSomething() {
        var c=new GenericClass<**ThisInstanceType**>();
        c.DoYourThing();
    }
}

What should I put instead ThisInstanceType in order to use generics with the type of "this" (the current child instance)?

I cannot change the declaration of Parent.DoSomething() . It cannot be void DoSomething<T>() .

Answer 1

If you make your abstract class generic, you can implement it like this:

public abstract class Parent<T> where T : Parent<T> {
    public void DoSomething() {
        var c = new GenericClass<T>();
        c.DoYourThing();
    }
 }

public class Child : Parent<Child> {}

Answer 2

You could do:

public abstract class Parent<T> : IParent
{
    public void DoSomething() {
        var c=new GenericClass<T>();
        c.DoYourThing();
    }
}

public sealed class Child : Parent<Child>
{
}

and if necessary you could add:

public interface IParent { void DoSomething(); }

BTW: If you include the full complete real life example, I might be able to give you a better solution

The other solution would be to use reflection to get the proper type and call the method at runtime...

Answer 3

If you really cannot design it properly, you could do it via reflection. I hesitate to suggest that, as you really should be redesigning your interface, but:

Type t = typeof(GenericClass<>).MakeGenericType(this.GetType());
object c = Activator.CreateInstance(t);
c.InvokeMember("DoYourThing", BindingFlags.Public | BindingFlags.Instance | BindingFlags.InvokeMethod, null, c, new object[] {});