AppDelegate

AppDelegate 繼承自Application， 負責控制遊戲的生命週期。

class  AppDelegate : private cocos2d::Application
{
public:
    AppDelegate();
    virtual ~AppDelegate();

    /**<span style="white-space:pre">	@brief 啓動結束以後，實現導演類和場景的初始化</span>

      * @return true   成功,APP繼續

<pre name="code" class="cpp">      * @return false   失敗,APP停止

*/ virtual bool applicationDidFinishLaunching(); /** @return false   失敗,APP停止

     */
    virtual void applicationDidEnterBackground();

    /** @brief  APP從後臺迴歸以後

      */
    virtual void applicationWillEnterForeground();

  在main函數中被調用

int APIENTRY _tWinMain(HINSTANCE hInstance,
                       HINSTANCE hPrevInstance,
                       LPTSTR    lpCmdLine,
                       int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // create the application instance
    AppDelegate app;
    return Application::getInstance()->run();
}

AppDelegate  繼承於Application.main調用了Application的run()函數；

在看到Application的構造函數

Application::Application()
: _instance(nullptr)
, _accelTable(nullptr)
{
    _instance    = GetModuleHandle(nullptr);
    _animationInterval.QuadPart = 0;
    CC_ASSERT(! sm_pSharedApplication);
    sm_pSharedApplication = this;
}

所以main函數中AppDelegate app;這句，主要是爲了實例化Application的單利對象，然後調用run(),run裏面又會調用applicationDidFinishLaunching,和mainLoop().

  // Initialize instance and cocos2d.
    if (!applicationDidFinishLaunching())
    {
        return 0;
    }

    auto director = Director::getInstance();
    auto glview = director->getOpenGLView();

    // Retain glview to avoid glview being released in the while loop
    glview->retain();

    while(!glview->windowShouldClose())
    {
        QueryPerformanceCounter(&nNow);
        if (nNow.QuadPart - nLast.QuadPart > _animationInterval.QuadPart)
        {
            nLast.QuadPart = nNow.QuadPart;
            
            director->mainLoop();
            glview->pollEvents();
        }