The GetWindowRgnBox function retrieves the dimensions of the tightest bounding rectangle for the window region of a window.
int GetWindowRgnBox( HWND hWnd, LPRECT lprc );
Handle to the window.
Pointer to a RECT structure that receives the rectangle dimensions, in device units relative to the upper-left corner of the window.
The return value specifies the type of the region that the function obtains. It can be one of the following values.
|COMPLEXREGION||The region is more than one rectangle.|
|ERROR||The specified window does not have a region, or an error occurred while attempting to return the region.|
|NULLREGION||The region is empty.|
|SIMPLEREGION||The region is a single rectangle.|
The window region determines the area within the window where the system permits drawing. The system does not display any portion of a window that lies outside of the window region. The coordinates of a window's window region are relative to the upper-left corner of the window, not the client area of the window.
To set the window region of a window, call the SetWindowRgn function.
|Minimum supported client||Windows 2000 Professional [desktop apps only]|
|Minimum supported server||Windows 2000 Server [desktop apps only]|
|Header||winuser.h (include Windows.h)|