The GetWindowDC function retrieves the device context (DC) for the entire window, including title bar, menus, and scroll bars. A window device context permits painting anywhere in a window, because the origin of the device context is the upper-left corner of the window instead of the client area.
GetWindowDC assigns default attributes to the window device context each time it retrieves the device context. Previous attributes are lost.
HDC GetWindowDC(
| HWND hWnd | // handle of window |
| ); |
Parameters
hWnd
Identifies the window with a device context that is to be retrieved.
Return Values
If the function succeeds, the return value is the handle of a device context for the specified window.
If the function fails, the return value is NULL, indicating an error or an invalid hWnd parameter.
Remarks
GetWindowDC is intended for special painting effects within a window's nonclient area. Painting in nonclient areas of any window is not recommended.
The GetSystemMetrics function can be used to retrieve the dimensions of various parts of the nonclient area, such as the title bar, menu, and scroll bars.
After painting is complete, the ReleaseDC function must be called to release the device context. Not releasing the window device context has serious effects on painting requested by applications.
See Also