WTL-一个用于简化WTL应用程序创建工作的类

手动编写WTL程序的入口点代码比较繁琐，将其封装成一个应用程序类之后可简化很多：

template<typename T, typename TMainWindow, bool bInitializeCom = true>

class CWTLApplicationT :

    public CAppModule

{

public:

    //Call this method in the application's entry point(_tWinMain(),ect...)

    int WinMain(HINSTANCE hInstance,LPTSTR lpCmdLine,int nCmdShow)

    {

        UNREFERENCED_PARAMETER(lpCmdLine);

        T* pT = static_cast<T*>(this);

        pT->OnStartup();

        HRESULT hr = S_OK;

        if (bInitializeCom)

        {

            hr = ::CoInitialize(NULL);

            // If you are running on NT 4.0 or higher you can use the following 

            // call instead to make the EXE free threaded. This means that calls 

            // come in on a random RPC thread.

            //  hr = ::CoInitializeEx(NULL, COINIT_MULTITHREADED);

            CHECKHR(hr);

        }

        // This resolves ATL window thunking problem when Microsoft Layer 

        // for Unicode (MSLU) is used

        ::DefWindowProc(NULL, 0, 0, 0L);

        

        pT->OnInitCommonControl();

        hr = Init(NULL, hInstance);

        CHECKHR(hr);

        int nRet = 0;

        {

            CMessageLoop msgLoop;

            AddMessageLoop(&msgLoop);

            TMainWindow wndMain;

            if(wndMain.Create(NULL,CWindow::rcDefault) == NULL)

            {

                ATLTRACE(_T("Failed to create Main window!\n"));

                return 0;

            }

            wndMain.ShowWindow(nCmdShow);

            wndMain.UpdateWindow();

            nRet = msgLoop.Run();

            RemoveMessageLoop();

        }

        Term();

        if (bInitializeCom)

            ::CoUninitialize();

        pT->OnShutdown();

        return nRet;

    }

protected:

    //Overridable methods

    void OnStartup(){}

    void OnShutdown(){}

    void OnInitCommonControl()

    {

        // Add flags to support other controls

        AtlInitCommonControls(ICC_COOL_CLASSES|ICC_BAR_CLASSES|ICC_WIN95_CLASSES);

    }

};

template<typename TMainWindow, bool bInitializeCom = true>

class CWTLApplication :

    public CWTLApplicationT<CWTLApplication<TMainWindow,bInitializeCom>, TMainWindow, bInitializeCom>

{

};

使用方法：

1.如果需要修改CWTLApplicationT的功能，可从CWTLApplicationT派生自己的新类，覆盖OnStartup()等函数，以添加自定义功能：

class CMainApp :

    public CWTLApplicationT<CMainApp,CMainWindow,false>

{

public:

    void OnStartup()

    {

        //Do some work when starting up...

    }

    void OnShutdown()

    {

        //Do some work when shuting down...

    }

};

CMainApp g_MainApp;

2.如果不需要修改CWTLApplicationT提供的功能，可直接使用typedef来定义一个新类：

typedef CWTLApplication<CMainWindow,false> CMainApp;

CMainApp g_MainApp;

3.定义完毕后，添加_tWinMain()入口函数：

int WINAPI _tWinMain(HINSTANCE hInstance,HINSTANCE,LPTSTR lpCmdLine,int nCmdShow)

{

    g_MainApp.WinMain(hInstance,lpCmdLine,nCmdShow);

}