cannot convert from 'class CWnd *' to 'struct HWND_ *'?该怎么解决

cannot convert from 'class CWnd *' to 'struct HWND__ *'??
这是什么意思,怎么修改代码?求教?

------解决方案--------------------
调用对应窗口类的 GetSafeHwnd()
------解决方案--------------------
GetSafeHwnd()
FromHandle()