UIToolbar偏置-黑带出现

Question

下面是我的Swift代码(AppDelegate.swift)：

var window: UIWindow?
var rootViewController :UIViewController?

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    if ((UIDevice.currentDevice().systemVersion as NSString).floatValue >= 7) {
        //yes, I'm using a newer iOS - greater/equal to iOS 7
        rootViewController  = Login(nibName:"Login",bundle:nil)
        let x = UIScreen.mainScreen().bounds.size.width
        let y = UIScreen.mainScreen().bounds.size.height
        let frame = CGRectMake(0,20,x,y)
        window = UIWindow(frame: frame)

        window!.rootViewController = rootViewController
        window!.makeKeyAndVisible()                

        //window!.frame =  CGRectMake(0,20,window!.frame.size.width,window!.frame.size.height-20);
     }

     return true
}

我正试着在20便士之前把屏幕抵消掉。

下面是我的模拟器使用上述代码的样子(错误！)：

​

​

如果我什么都不做(做错了！)

​

​

这就是我想要的样子！

​

​

我已经干了好几个小时了。

我希望有一种强有力的、易于管理的方式，在20%之前将所有的东西都降下来。

(p.s.我是，而不是使用故事板的)

Answer 1

这似乎是可行的：

        rootViewController  = Login(nibName:"Login",bundle:nil)

        if ((UIDevice.currentDevice().systemVersion as NSString).floatValue >= 8) {
            //For iOS 8
            rootViewController?.providesPresentationContextTransitionStyle = true
            rootViewController?.definesPresentationContext = true;
            rootViewController?.modalPresentationStyle = UIModalPresentationStyle.CurrentContext
        }else{
            //For iOS 7
            rootViewController?.modalPresentationStyle = UIModalPresentationStyle.CurrentContext
        }
        let x = UIScreen.mainScreen().bounds.size.width
        let y = UIScreen.mainScreen().bounds.size.height
        let frame = CGRectMake(0, 0, x, y)
        window = UIWindow(frame: frame)
        window!.rootViewController = rootViewController
        window!.makeKeyAndVisible()