UIScreen(屏幕)、UIWindow(画框)、UIView(画布)、didFinishLaunchingWithOptions、UIViewController各个方法的加载顺序
//didFinishLaunchingWithOptions方法:顾名思义。在app开始运行时会调用里面的方法。-(BOOL)application:(UIApplication*)applicationdidFinishLaunchingWithOptions:(NSDictionary*)launchOptions{ //返回的是带有状态栏的矩形 self.window=[[[U