MFC Inheritance

Why is it when you declare a class and derive it from a CWnd you can't create a new class of it because it can't access the protected members.
You can't create a new class of what ?

Why is it when you declare a class and derive it from a CWnd you can't create a new class of it because it can't access the protected members. The MFC Framework does all the work for you on it. I'm sure this is easy to understand.

Jack Adkins
No it's not clear.
What protected members?
How did you derive from CWnd?
How did you try to instantiate/create (?) an object of derived class?

Usually the reason that you set a amember variable to protected is to force a programmer to only modify that variable in a member function of a class derrived from the base class or the member function of the base class its self.

You are asking for a very general kind of help. Why did a programmer do this? Well you have to take a common sense approach to this. Maybe he set to protected on accident and had an itch to scratch so he forgot to set it public or maybe not.

Why dont you supply some source code. Pref as little as possible. Even just use the code tags if you can.

ahoodin

The classess like CWinApp are created using Singleton design, ie only one instance of the Class can be instantiated by the application. Its why the constructors of this type of class who is considered as singleton classess is kept protected.