The active window or NULL if no window was active at the time of the call. The pointer may be temporary and should not be stored for later use.
The active window or NULL if no window was active at the time of the call. The pointer may be temporary and should not be stored for later use.
返回活动窗口，如果在被调用时没有活动窗口，则返回NULL。这个指针可能是临时的，不能被保存以供将来使用。