Troubleshoot C + + methods that cannot be converted from void to lresult _c language

This should be an MFC program, On_message is to add a message response function, this sentence is to add a hotkey wm_hotkey response function. When you register the hotkey, when the user presses the hot key, the Onhotkey function is executed to process the message. The error should be onhotkey the declaration of this function is wrong, the return value should be lresult. VS2008 the message is more stringent inspection, previously in VC6 completely normal operation of the message map under the VS2008 compiler does not pass

On_message (Wm_message,onmymessage);
The OnMessage return value must be lresult in the form of: afx_msg lresult OnMessage (WPARAM, LPARAM);
If it does not, then there is an error message: Error C2440: "static_cast": Cannot convert from "void" (__thiscall cmainframe::*) (void) to Lresult (__thiscall cwnd::* ) (Wparam,lparam) "

The solution is as follows: first, change the original message function return value type to LRESULT, the function can be casually written back 0, and then the message function parameters must be rewritten (WPARAM Wparam,lparam LPARAM) Regardless of these two.