CWnd::OnFontChange
afx_msgvoidOnFontChange();
Remarks
All top-level windows in the system receive an OnFontChange call from the framework after the application changes the pool of font resources.
An application that adds or removes fonts from the system (for example, through the or Windows function) should send the message to all top-level windows.
To send this message, use the Windows function with the hWnd parameter set to HWND_BROADCAST.