Sets the mouse capture to the specified window belonging to the current thread. SetCapture captures mouse input either when the mouse is over the capturing window, or when the mouse button was pressed while the mouse was over the capturing window and the button is still down. Only one window at a time can capture the mouse.
HWND SetCapture( HWND hWnd );
int SetCapture(int hWnd) => _SetCapture(hWnd);