Tips need for building an application framework

[D002199]

Hi,

Can some of you give me some tips about how to build an application framework?

What I have done is;

(1) Define a base class with some virtual functions (abstract class)
(2) Derive a class from base and implement all the functions
(3) Build implementation into a static library

(3) Provide a header file which include only base class & library to client application (I want to hide all the impelmentation details from client application.
(4) in client application, declare a void pointer
(5) in client app, try to downcast pointer to derived class in library (no compiling error)
(6) make a call to functions (e.g ptr->method1, compilig error ???)

I know some wrong, but don't know where problem is? Is it the right way to build an application framework?

Please help,

Thanks in advance,