初始化windows窗口

LRESULT WINAPI WndProc(HWND hWnd,UINT msg,WPARAM wParam,LPARAM lParam)
{
    PAINTSTRUCT ps;
    switch (msg)
    {
    case WM_PAINT:
        {
            BeginPaint(hWnd,&ps);
            EndPaint(hWnd,&ps);
            return 0;
        }
    case WM_DESTROY:
        {
            PostQuitMessage(0);
            return 0;
        }
    }

    return DefWindowProc(hWnd,msg,wParam,lParam);
}
void initWndClass(HINSTANCE hInstance,WNDCLASSEX &wndClass)
{
    wndClass.cbSize = sizeof(WNDCLASSEX);
    wndClass.style = CS_HREDRAW | CS_VREDRAW;
    wndClass.lpfnWndProc = WndProc;
    wndClass.cbClsExtra = 0;
    wndClass.cbWndExtra = 0;
    wndClass.hInstance = hInstance;
    wndClass.hIcon = LoadIcon(NULL,IDI_APPLICATION);
    wndClass.hCursor = LoadCursor(NULL,IDC_ARROW);
    wndClass.hbrBackground = (HBRUSH)GetStockObject(GRAY_BRUSH);
    wndClass.lpszClassName = TEXT(CLASSNAME);
    wndClass.lpszMenuName = NULL;
    wndClass.hIconSm = LoadIcon(NULL,IDI_WINLOGO);
}

int WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nShowCmd)
{
    HWND hWnd;

    WNDCLASSEX wndClass;
    initWndClass(hInstance,wndClass);

    RegisterClassEx(&wndClass);

    hWnd = CreateWindow(
        TEXT(CLASSNAME),
        TEXT(APPNAME),
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        SCREEN_W,
        SCREEN_H,
        NULL,
        NULL,
        hInstance,
        NULL
        );

    if (NULL == hWnd)
    {
        MessageBox(NULL,TEXT("NULL == hWnd"),NULL,MB_OK);
        return 0;
    }

    UpdateWindow(hWnd);
    ShowWindow(hWnd,nShowCmd); 
    MSG msg;
    while (true)
    {
        if ( PeekMessage(&msg,NULL,0,0,PM_REMOVE) )
        {
            if (WM_QUIT == msg.message)
            {
                break;
            }
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        else 
        {
            Render();
        }
    }
    Release();
    return msg.lParam;
}