Visual C++ and MFC Programming 2nd Edition

Visual C++ and MFC Fundamentals Chapter 12: Dialog-Based Windows

The second option used to add a control to an application consists of programmatically

creating it. To do this, you can call either the CreateWindow() or the

CreateWindowEx() functions.

All visible controls of the MFC library are based on the CWnd class. This class is

equipped with all the primary functionality that a regular window object needs. As the

parent of all visible window classes, it provides the other controls with properties and

methods to implement their appearance and behavior. To use the CWnd class you have

various options:

?? You can directly derive a class from CWnd

?? You can use one of the CWnd-derived classes (CView, CFrameWnd, etc)

?? You can derive a class from one of the CWnd-derived classes; for example you

can create a class based on CStatic

?? You can directly declare a CWnd variable in your application and initialize it

with the class of your choice

To create a control using a known class, you must declare a variable of the class on which

the control is based. Every control is based on a specific class, and that class is directly or

indirectly derived from CWnd. An example of such a declaration would be:

void CParentLoader::TodaysMainEvent()

{

CStatic Label;

}

You can also declare the variable as a pointer. In this case, make sure that you initialize

the class using the new operator. An example would:

void CParentLoader::TodaysMainEvent()

{

CStatic *Label = new CStatic;