我想刪除屏幕頂部的狀態(tài)欄。這不起作用：func application(application: UIApplication,didFinishLaunchingWithOptions launchOptions: NSDictionary?)-> Bool{        application.statusBarHidden = true        return true}我也嘗試過：func application(application: UIApplication,didFinishLaunchingWithOptions launchOptions: NSDictionary?)-> Bool{    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)    var controller = UIViewController()    application.statusBarHidden = true    controller.setNeedsStatusBarAppearanceUpdate()    var view = UIView(frame: CGRectMake(0, 0, 320, 568))    view.backgroundColor = UIColor.redColor()    controller.view = view    var label = UILabel(frame: CGRectMake(0, 0, 200, 21))    label.center = CGPointMake(160, 284)    label.textAlignment = NSTextAlignment.Center    label.text = "Hello World"    controller.view.addSubview(label)    self.window!.rootViewController = controller    self.window!.makeKeyAndVisible()    return true}