程序代码：

//注册窗口信息
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEX wcex;

    wcex.cbSize = sizeof(WNDCLASSEX)  //WNDCLASSEX的大小

    wcex.style = CS_HREDRAW | CS_VREDRAW; //
    wcex.lpfnWndProc = (WNDPROC)WndProc; //窗口处理函数指针
    wcex.cbClsExtra = 0; //指定紧跟在窗口类结构后的附加字节数
    wcex.cbWndExtra = 0; //指定紧跟在窗口事例后的附加字节数
    wcex.hInstance = hInstance;//本模块的事例句柄
    wcex.hIcon = NULL;         //图标的句柄
    wcex.hCursor = LoadCursor (NULL, IDC_ARROW);//光标的句柄
    wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW); //背景画刷的句柄
    wcex.lpszMenuName = NULL;                   //指向菜单的指针
    wcex.lpszClassName = "STATIC";              //指向类名称的指针
    wcex.hIconSm = NULL;                        //和窗口类关联的小图标

    return RegisterClassEx(&wcex);              //注册窗口
}

error C2440: 'type cast' : cannot convert from 'unsigned int' to 'struct tagWNDCLASSEXA'

wcex.cbSize = sizeof(WNDCLASSEX);