Error C2440: ' static_cast ': cannot convert from ' void (__thiscall CMainFrame::*) (void) ' to ' Lresul

Cannot convert void (_thiscall CMainFrame::*) (void) to Lresult (__thiscall CWnd::*) (Wparam,lparam)
The development platform is upgraded from VC6.0 to VS2005, the original project needs to be migrated, and a similar error may be encountered:
Error C2440: ' static_cast ': cannot convert from ' void (__thiscall CMainFrame::*) (void) ' to ' Lresult (__thiscall CWnd::* ) (Wparam,lparam) '

VS2005 the message is more stringent inspection, previously in VC6 completely normal operation of the message map under the VS2005 compiler does not pass

On_message (Wm_message,onmymessage);
The OnMyMessage return value must be lresult, in the form of: afx_msg lresult OnMyMessage (WPARAM, LPARAM) and, if not, an error message:
Error C2440: "static_cast": Cannot convert from "void" (__thiscall Cpppview::*) (Wparam,lparam) to Lresult (__thiscall CWnd::*) (WPARAM, LPARAM) "
There is no function with that name in the range that matches the target type
Error C2440: "static_cast": Cannot convert from "void" (__thiscall Cpppview::*) (void) to Lresult (__thiscall CWnd::*) (Wparam,lparam)
There is no function with that name in the range that matches the target type

The workaround is as follows:

First, the original message function return value type is changed to Lresult, the function can be arbitrarily written to TRUE; The parameters of the message function must then be rewritten (WPARAM Wparam,lparam LPARAM) Regardless of whether the two parameters are used or not, and finally, the message map, such as On_message (wm_message,& onmymessage)