UIView框架在方向改變後沒有更新

Question

如何使用Swift 3檢測方向改變？

我需要在更改後檢測它以計算幀大小。

編輯：

我問這個問題，因爲我需要重繪視圖的方向變化像這樣一個問題：Can't get background gradient to fill entire screen upon rotation

我不知道如何實現標記爲正確答案的答案。

我嘗試另一個答案

self.backgroundImageView.layer.sublayers?.first?.frame = self.view.bounds 

，但它不工作。

在viewDidLoad()我

let color1 = UIColor(red: 225.0/255.0, green: 210.0/255.0, blue: 0.0/255.0, alpha: 1.0).cgColor 
     let color2 = UIColor(red: 255.0/255.0, green: 125.0/255.0, blue: 77.0/255.0, alpha: 1.0).cgColor 

     let gradientLayer = CAGradientLayer() 
     gradientLayer.colors = [color1, color2] 
     gradientLayer.locations = [ 0.0, 1.0] 
     gradientLayer.frame = self.view.bounds 

     self.view.layer.insertSublayer(gradientLayer, at: 0) 

Answer 1

上述接受的答案返回幀大小不updating..You需要過渡完成後得到的幀大小。

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) { 

     coordinator.animate(alongsideTransition: { (UIViewControllerTransitionCoordinatorContext) -> Void in 

      let orient = UIApplication.shared.statusBarOrientation 

      switch orient { 

      case .portrait: 

       print("Portrait") 

      case .landscapeLeft,.landscapeRight : 

       print("Landscape") 

      default: 

       print("Anything But Portrait") 
      } 

      }, completion: { (UIViewControllerTransitionCoordinatorContext) -> Void in 
       //refresh view once rotation is completed not in will transition as it returns incorrect frame size.Refresh here   

     }) 
     super.viewWillTransition(to: size, with: coordinator) 

    } 

Answer 2

添加此功能，並you'll檢測取向變化：

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) { 
    if UIDevice.current.orientation.isLandscape { 
     print("Landscape") 
    } else if UIDevice.current.orientation.isPortrait { 
     print("Portrait") 
    } 
} 

Answer 3

要獲得方向變化回調您需要添加此通知

NotificationCenter.default.addObserver(self, selector: #selector(ViewController.rotated), name: NSNotification.Name.UIDeviceOrientationDidChange, object: nil) 

並且您需要實施此方法

func rotated() { 
    if(UIDeviceOrientationIsLandscape(UIDevice.current.orientation)) 
    { 
     print("landscape") 
    } 

    if(UIDeviceOrientationIsPortrait(UIDevice.current.orientation)) 
    { 
     print("Portrait") 
    } 
} 

Answer 4

嘗試transition.So你的觀點在此之前

override func viewWillLayoutSubviews() { 
    super.viewWillLayoutSubviews() 
    if UIInterfaceOrientationIsLandscape(UIApplication.sharedApplication().statusBarOrientation) { 

     print("Landscape mode called") 

     if UI_USER_INTERFACE_IDIOM() == .Pad { 
      print("Landscape mode in ipad"); 

     } 
     else 
     { 
      print("Landscape mode in Iphone ") 

     } 
    } else { 
     print("Portrait mode called") 
     if UI_USER_INTERFACE_IDIOM() == .Pad { 

      print("Portrait mode called in ipad") 
     } 
     else 
     { 
      print("Portrait mode called in iphone") 
     } 
    } 
} 
override func willRotateToInterfaceOrientation(toInterfaceOrientation:UIInterfaceOrientation, duration: NSTimeInterval) { 
    print("willRotateToInterfaceOrientation method called"); 
    //Here you can invalidateLayout() 
} 

Answer 5

這是我的解決方案基於以下要求：

（1）我的佈局需要改變根據其尺寸較大，高度或寬度。 （基本上是縱向或橫向，但在未來...？）

（2）我的應用程序是通用的，所以我不能考慮大小類或與它們相關的任何覆蓋。

（3）我的應用程序也有一個照片編輯擴展，所以UIApplication不可用。 （另外，landscapeLeft和landscapeRight等方向不適用於此類擴展名。）

注意：爲了完整性，我添加了AutoLayout的結構。

的UIViewController：

var p = [NSLayoutConstraint]() 
var l = [NSLayoutConstraint]() 
var initialOrientation = true 
var isInPortrait = false 

override func viewDidLoad() { 
    super.viewDidLoad() 
    // set up all constraints, including common, portrait and landscape 
    setUpConstraints() 
} 

override func viewWillLayoutSubviews() { 
    super.viewWillLayoutSubviews() 
    if initialOrientation { 
     initialOrientation = false 
     if view.frame.width > view.frame.height { 
      isInPortrait = false 
     } else { 
      isInPortrait = true 
     } 
     orientationChanged() 
    } else { 
     if view.orientationHasChanged(&isInPortrait) { 
      orientationChanged() 
     } 
    } 
} 

func orientationChanged() { 
    // this was split out because of other app-specific logic 
    view.setOrientation(p, l) 
} 

的UIView：

extension UIView { 

    public func orientationHasChanged(_ isInPortrait:inout Bool) -> Bool { 
     // always check against isInPortrait to reduce unnecessary AutoLayout changes! 
     if self.frame.width > self.frame.height { 
      if isInPortrait { 
       isInPortrait = false 
       return true 
      } 
     } else { 
      if !isInPortrait { 
       isInPortrait = true 
       return true 
      } 
     } 
     return false 
    } 
    public func setOrientation(_ p:[NSLayoutConstraint], _ l:[NSLayoutConstraint]) { 
     NSLayoutConstraint.deactivate(l) 
     NSLayoutConstraint.deactivate(p) 
     if self.bounds.width > self.bounds.height { 
      NSLayoutConstraint.activate(l) 
     } else { 
      NSLayoutConstraint.activate(p) 
     } 
    } 
}