"但是矩形大小还在"
使用 rgn
SetWindowRgn
The SetWindowRgn function sets the window region of a window. 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
int SetWindowRgn(
HWND hWnd, // handle to window whose window region is to be set
HRGN hRgn, // handle to region
BOOL bRedraw // window redraw flag
);