GetWindowDC function user32
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.
HDC GetWindowDC(
HWND hWnd
);
Implementation
int GetWindowDC(int hWnd) => _GetWindowDC(hWnd);