Creating Windows
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The latest version of this topic can be found at Creating Windows.
The framework automatically creates most of the windows you need in a framework program. Document/View Creation shows how the framework creates the frame windows associated with documents and views. But for special purposes you can create your own windows — including your own child windows of frame windows or views — in addition to the windows supplied by the framework.
What do you want to know more about
Registering window "classes" (as opposed to C++ window objects)