C# internal access modifiers

Question

I want to seal of classes in a namespace. I was looking at the "internal" access modifier, but this only seems to seal of classes in an assembly. Can I seal of classes in a namespace?

Or do I have to move stuff into an seperate assembly? But then I will have the problem of visual studio refusing circular assembly references.

Answer 1

No, there is no namespace-specific modifier. One option would be to use inheritance and a "protected" modifier, but having an internal constructor on the base-class so that external code can't subclass it. That might help.

Answer 2

It is not possible with C#.

Namespace-level members can only be either public or internal

You can however, use nested class in C#

namespace A {
    public class B {

        protected class C { }
    }

    public class D {

        void E() {
            var F = new A.B();    // ok!
            var G = new A.B.C();  // error!
        }
    }
}

Answer 3

You can still use the internal keyword and expose the internal classes to another assembly via the InternalsVisibleTo attribute in the AssemblyInfo.cs file.