What's the difference between a public constructor in an internal class and an internal constructor?

Question

I have an internal class, an internal constructor won\'t allow it to be used in a generic collection so I changed it to public. What\'s the accessibility if you have a publi

Answer 1

A public class with an internal constructor can still be used by outside code, if you return an object of that class from a public function.

Outside code then has access to that object, but still can not create a new one.

Assembly 1:

public class Exclusive
{
  internal Exclusive() {}
  public void DoSomething() {}
}

public class Factory
{
  public Exclusive GetExclusive() { return new Exclusive(); }
}

Assembly 2:

Factory MyFactory = new Factory();
Exclusive MyExclusive = MyFactory.GetExclusive(); // Object is created in Assembly 1
MyExclusive.DoSomething();

Exclusive MyExclusive = new Exclusive(); // Error: constructor is internal

Whereas an internal class can not be used outside the assembly at all:

Assembly 1:

internal class Exclusive
{
  public Exclusive() {}
  public void DoSomething() {}
}

public class Factory
{
  public Exclusive GetExclusive() { return new Exclusive(); }
}

Assembly 2:

Factory MyFactory = new Factory();
Exclusive MyExclusive = MyFactory.GetExclusive(); // Error: class Exclusive not found