看MSDN中CwinApp的CWinApp::m_pszAppName ，介绍如下
m_pszAppName is a public variable of type const char*.
Note If you assign a value to m_pszAppName, it must be dynamically allocated on the heap. The CWinApp destructor calls free( ) with this pointer. You many want to use the _tcsdup( ) run-time library function to do the allocating. Also, free the memory associated
with the current pointer before assigning a new value. For example:
//First free the string allocated by MFC at CWinApp startup.
//The string is allocated before InitInstance is called.
free((void*)m_pszAppName);
//Change the name of the application file.
//The CWinApp destructor will free the memory.
m_pszAppName=_tcsdup(_T(“d:\\somedir\\myapp.exe”));
若要自行分配AppName，则先释放m_pszAppName，再通过动态内存分配更改appname
即
free((void*)m_pszAppName);
m_pszAppName=_tcsdup(_T(“d:\\somedir\\myapp.exe”));
即可