关于Single Document中窗口对象的生成.

[OneMoreFreeMan]

BOOL CBoschApp::InitInstance()
{
AfxEnableControlContainer();
#ifdef _AFXDLL
Enable3dControls(); // Call this when using MFC in a shared DLL
#else
Enable3dControlsStatic(); // Call this when linking to MFC statically
#endif

SetRegistryKey(_T("Local AppWizard-Generated Applications"));

LoadStdProfileSettings(); // Load standard INI file options (including MRU)

CSingleDocTemplate* pDocTemplate;
pDocTemplate = new CSingleDocTemplate(
IDR_MAINFRAME,
RUNTIME_CLASS(CBoschDoc),
RUNTIME_CLASS(CMainFrame), // main SDI frame window
RUNTIME_CLASS(CBoschView));
AddDocTemplate(pDocTemplate);

CCommandLineInfo cmdInfo;
ParseCommandLine(cmdInfo);

if (!ProcessShellCommand(cmdInfo))
return FALSE;

m_pMainWnd->ShowWindow(SW_SHOW);
m_pMainWnd->UpdateWindow();

return TRUE;
}
我建立的是MFC Single Doument程序，在InitInstance()中只有
m_pMainWnd->ShowWindow(SW_SHOW);
m_pMainWnd->UpdateWindow();
而没有找到m_pMainWnd的初始化语句,MFC中在哪里生成的m_pMainWnd所指向的对象?