If the function succeeds, the return value specifies whether the key was pressed since the last call to GetAsyncKeyState, and whether the key is currently up or down. If the most significant bit is set, the key is down, and if the least significant bit is set, the key was pressed after the previous call to GetAsyncKeyState. However, you should not rely on this last behavior; for more information, see the Remarks.
The return value is zero for the following cases:
※The current desktop is not the active desktop 当前桌面不是活动桌面
※The foreground thread belongs to another process and the desktop does not allow the hook or the journal record. 前台线程属于另一个进程。桌面不允许挂钩或日志记录。