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？

[解决办法]
调用对应窗口类的 GetSafeHwnd()
[解决办法]
GetSafeHwnd()
FromHandle()