WM_SYNCPAINT message
The WM_SYNCPAINT message is used to synchronize painting while avoiding linking independent GUI threads.
A window receives this message through its WindowProc function.
LRESULT CALLBACK WindowProc(
HWND hwnd,
UINT uMsg,
WPARAM wParam,
LPARAM lParam
);
Parameters
-
wParam
-
This parameter is not used.
-
lParam
-
This parameter is not used.
Return value
An application returns zero if it processes this message.
Remarks
When a window has been hidden, shown, moved, or sized, the system may determine that it is necessary to send a WM_SYNCPAINT message to the top-level windows of other threads. Applications must pass WM_SYNCPAINT to DefWindowProc for processing. The DefWindowProc function will send a WM_NCPAINT message to the window procedure if the window frame must be painted and send a WM_ERASEBKGND message if the window background must be erased.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows 2000 Professional [desktop apps only] |
| Minimum supported server |
Windows 2000 Server [desktop apps only] |
| Header |
|
See also