WNDCLASSEX m_wc;
Remarks
Maintains the window class information in a WNDCLASSEX structure.
If you have specified the DECLARE_WND_CLASS (the default in CWindowImpl) or the DECLARE_WND_CLASS_EX macro, m_wc contains information about a new window class.
If you have specified the DECLARE_WND_SUPERCLASS macro, m_wc contains information about a superclass — a window class that is based on an existing class but uses a different window procedure. m_lpszOrigName and pWndProc save the existing window class’s name and window procedure, respectively.