ID Number: Q33096
1.x 2.03 2.10 3.00 3.10
WINDOWS
Summary:
When an application uses the BeginPaint or GetDC function to obtain a
device context (DC) its client window and draws into this DC, Windows
clips the output to the edge of the client window. While this is
usually the desired effect, there are circumstances where an
application draws outside the client area of its window.
The GetWindowDC function provides a DC that allows an application to
draw anywhere within its window, including the nonclient area.
In the Windows environment, the display is a scarce resource that is
shared by all applications running in the system. Most of the time, an
application should restrict its output to the area of the screen it
has been assigned by the user. However, an application can use the
CreateDC function to obtain a DC for the entire display, as follows:
hDC = CreateDC("DISPLAY", NULL, NULL, NULL);
Device contexts are another scarce resource in the Windows
environment. When an application creates a DC in response to a
WM_PAINT message, it must call the DeleteDC function to free the DC
before it completes processing of the message.
Painting in the nonclient area of a window is not recommended. If an
application changes the nonclient area of its window, the user can
become confused because the familiar Windows controls change
appearance or are not available. An application should not corrupt
other windows on the display.
Additional reference words: 1.x 2.03 2.10 3.00 3.10 SR# G880706-1646
2.x