無法從超級視圖中刪除（swift2）

Question

我無法使用以下代碼從超級視圖中刪除？ 這是什麼？我嘗試了一切，但似乎它根本不工作。我添加更多的細節，所以我沒有得到這個非常惱人的警報，告訴我，我的帖子主要是代碼....

let controller = storyboard!.instantiateViewControllerWithIdentifier("OrderViewController") 
      controller.view.frame = CGRectMake(self.view.frame.size.width/2 - 100, self.view.frame.size.height/2 - 100, 200, 200) 

     if sender.selected { 

      sender.selected = false 

      controller.view.transform = CGAffineTransformIdentity 

      [UIView .animateWithDuration(0.2, delay: 0.0, options: UIViewAnimationOptions.CurveEaseOut, animations: { 

       controller.view.transform = CGAffineTransformMakeScale(0.01, 0.01); 

       }, completion: { finished in 

       controller.willMoveToParentViewController(nil) 
       controller.view .removeFromSuperview() 
       controller.removeFromParentViewController() 


      })] 
      print("close") 

     } 

     else { 

      sender.selected = true 

      addChildViewController(controller) 
      view.addSubview(controller.view) 
      controller.didMoveToParentViewController(self) 

      controller.view.transform = CGAffineTransformMakeScale(0.01, 0.01); 
      [UIView .animateWithDuration(0.2, delay: 0.0, options: UIViewAnimationOptions.CurveEaseOut, animations: { 

       controller.view.transform = CGAffineTransformIdentity 

       }, completion: nil)] 


      print("present") 

     } 

Answer 1

有一個奇怪的Objective-C語法組合（UIView動畫塊周圍的方括號）和swift。如果這個編譯沒有錯誤，我很驚訝！

你幾乎在那裏，主要的問題是，每調用一段代碼就會實例化一個'OrderViewController'的新實例。

你只想創建它，如果它不存在（當你想顯示它）。當你準備好隱藏它時，你想獲得對現有控制器的引用，並執行動畫等來隱藏它。

爲此，您需要在該代碼塊的本地範圍之外保留對其的引用。

這裏是你展示如何可能做到這一點的例子：

import UIKit 

class ViewController: UIViewController { 

    // keep a reference to the OrderViewController after it's been created 
    var controller:UIViewController? 

    @IBAction func buttonTapped(sender: AnyObject) { 

     // instead of using button selected state, just check to see if 
     // self.controller is nil or not 

     if let existingController = self.controller { 
      // controller already exists, lets hide it 

      existingController.view.transform = CGAffineTransformIdentity 

      UIView.animateWithDuration(0.2, delay: 0.0, options: UIViewAnimationOptions.CurveEaseOut, animations: { 

       existingController.view.transform = CGAffineTransformMakeScale(0.01, 0.01); 

       }, completion: { _ in 

        existingController.willMoveToParentViewController(nil) 
        existingController.view.removeFromSuperview() 
        existingController.removeFromParentViewController() 

        // make this nil, so that next time the button is 
        // tapped we'll go though the process of creating it again 
        self.controller = nil 

      }) 
      print("close") 
     } 
     else { 
      // controller doesn't exist, lets instanstiate and show it 

      let newController = storyboard!.instantiateViewControllerWithIdentifier("OrderViewController") 

      newController.view.frame = CGRectMake(self.view.frame.size.width/2 - 100, self.view.frame.size.height/2 - 100, 200, 200) 

      addChildViewController(newController) 
      view.addSubview(newController.view) 
      newController.didMoveToParentViewController(self) 

      newController.view.transform = CGAffineTransformMakeScale(0.01, 0.01) 

      UIView.animateWithDuration(0.2, delay: 0.0, options: UIViewAnimationOptions.CurveEaseOut, animations: { 

       newController.view.transform = CGAffineTransformIdentity 

       }, completion: { _ in 

        // keep a reference to this controller you've just created, 
        // so that next time the button is tapped you can close it 
        self.controller = newController 
      }) 

      print("present") 

     } 
    } 
} 

如果你在一個非常簡單的應用程序（只是一對夫婦的屏幕）工作那麼這個方法是好的。

但是....如果您計劃更復雜的事情，您可能需要使用自定義UISegue或UIPresentationController和UIViewControllerAnimatedTransitioning的混合進行調查，以便所有動畫邏輯都不會鎖定到您的查看控制器代碼。