|
Overview |
|
|
|
Group |
|
|
|
Quick Info
Windows NT
| Yes
| Win95
| Yes
| Win32s
| Yes
| Import Library
| -
| Header File
| winuser.h
| Unicode
| No
| Platform Notes
| None
|
|
|
WM_ERASEBKGND
An application sends the WM_ERASEBKGND message 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.
WM_ERASEBKGND
hdc = (HDC) wParam; // handle of device context
Parameters
hdc
Value of wParam. Identifies the device context.
Return Values
An application should return nonzero if it erases the background; otherwise,
it should return zero.
Remarks
The DefWindowProc function erases the background by using the class background brush specified
by the hbrBackground member of the WNDCLASS structure. If hbrBackground is 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 fErase member of the PAINTSTRUCT structure will be TRUE.)
See Also
BeginPaint, DefWindowProc, PAINTSTRUCT, WM_ICONERASEBKGND, WNDCLASS
Related Links
Software for Delphi and C++ Builder developers
Software for Visual Studio .NET developers
Software for Visual Basic 6 developers
Delphi Tips&Tricks
MegaDetailed.NET
TMS Scripter Studio Pro components for Delphi/C++Builder
More Online Helps
Win32 Multimedia Programmer's Reference (mmedia.hlp)
OLE Programmer's Reference (ole.hlp)
Microsoft Windows Pen API Programmer's Reference (penapi.hlp)
Microsoft Windows Sockets 2 Reference (sock2.hlp)
Microsoft Windows Telephony API (TAPI) Programmer's Reference (tapi.hlp)
Unix Manual Pages
|
