GetWindowRgnBox function (winuser.h)
The GetWindowRgnBox function retrieves the dimensions of the tightest bounding rectangle for the window region of a window.
Syntax
int GetWindowRgnBox(
[in] HWND hWnd,
[out] LPRECT lprc
);
Parameters
[in] hWnd
Handle to the window.
[out] lprc
Pointer to a RECT structure that receives the rectangle dimensions, in device units relative to the upper-left corner of the window.
Return value
The return value specifies the type of the region that the function obtains. It can be one of the following values.
| Value | Meaning |
|---|---|
| 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. |
Remarks
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.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only] |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | winuser.h (include Windows.h) |
| Library | User32.lib |
| DLL | User32.dll |
| API set | ext-ms-win-ntuser-draw-l1-1-0 (introduced in Windows 8) |