Copies the text of the specified window's title bar (if it has one) into a buffer. If the specified window is a control, the text of the control is copied. However, GetWindowText cannot retrieve the text of a control in another application.
int GetWindowTextW( HWND hWnd, LPWSTR lpString, int nMaxCount );
int GetWindowText(int hWnd, Pointer<Utf16> lpString, int nMaxCount) => _GetWindowText(hWnd, lpString, nMaxCount);