Painting and Repainting

In character-mode environments, programs can generally write to any part of the video display. What the program puts on the display will stay there and not mysteriously disappear. The program can then discard the information needed to re-create the screen display.

In Windows, you can draw text and graphics only in the client area of your window, and you cannot be assured that what you put will remain there until your program specifically writes over it. For instance, the user may move another program’s window on the screen so that it partially covers your application’s window. Windows will not attempt to save the area of your window that the other program covers. When the program is moved away, Windows will request that ...

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