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4/8/2010

This message is sent by an application when the window background must be erased, for example, when a window is resized. The message is sent to prepare an invalidated portion of a window for painting.

Syntax 

WM_ERASEBKGND 
hdc = (HDC) 
wParam;

Parameters

hdc

Handle to the device context.

Return Value

An application should return nonzero if it erases the background; otherwise, it should return zero.

Remarks

The DefWindowProcfunction erases the background by using the class background brush specified by the hbrBackgroundmember of the WNDCLASS. If hbrBackgroundis NULL, the application should process the WM_ERASEBKGND message and erase the background.

An application should return nonzero in response to WM_ERASEBKGND if it processes the message and erases the background; this indicates that no further erasing is required. If the application returns zero, the window will remain marked for erasing. (Typically, this indicates that the fErasemember of the PAINTSTRUCTstructure will be TRUE.)

Requirements

Header winuser.h
Windows Embedded CE Windows CE 1.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also