swift - 将编程创建的视图连接到 IB

Question

按照这个答案，我设法将半模态呈现添加ViewControllerB到ViewControllerA. 但是，在示例中，ViewControllerA只是一个红色视图。我想将它连接到 IB 以便对其进行自定义。我尝试在类的 IB 中创建一个视图控制器ViewControllerB并将其视图之一连接到，@IBOutlet var menuView: UIView!而不是以menuView编程方式创建（如示例中所示）。但是，在作为子视图nil添加menuView到视图时发现。任何帮助都会很棒。谢谢！

Answer 1

几点观察：

1. 在那个例子中，有一行说：

   let vc = ViewControllerB()
   

   您可以在 NIB 中定义此视图控制器的视图，这样可以正常工作。但是，如果您使用的是故事板，请将其替换为...

   let vc = storyboard!.instantiateViewController(withIdentifier: “identifier")
   

   ...identifier您在 IB 的“身份检查器”中为该场景提供的作为“故事板 ID”的字符串在哪里。

2. 如果这是由按钮或类似的东西触发的，您也可以gotoVCB在该示例中删除它，然后像往常一样在 IB 中进行模态演示（例如control- 从按钮拖动到下一个场景）并选择“以模态方式呈现”。但是您必须确保配置了所有init方法，例如：

   class ViewControllerB: UIViewController {
   
       // used if you use NIBs or just call `init()`
   
       override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
           super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
           configure()
       }
   
       // used if you use storyboards
   
       required init?(coder aDecoder: NSCoder) {
           super.init(coder: aDecoder)
           configure()
       }
   
       private func configure() {
           modalPresentationStyle = .custom
           transitioningDelegate = self
       }
   
       ...
   }
   

3. 与直接问题无关，我可能建议将该答案的代码拆分为单独的对象，以防止视图控制器“膨胀”，更好地分离过渡委托对象、动画控制器等之间的职责。

   例如，也许：

   class ViewControllerB: UIViewController {
   
       let customTransitioningDelegate = PopUpMenuTransitioningDelegate()
   
       override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
           super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
           configure()
       }
   
       required init?(coder aDecoder: NSCoder) {
           super.init(coder: aDecoder)
           configure()
       }
   
       func configure() {
           modalPresentationStyle = .custom
           transitioningDelegate = customTransitioningDelegate
       }
   
   }
   

   和

   class PopUpMenuTransitioningDelegate: NSObject, UIViewControllerTransitioningDelegate {
       func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
           return PopUpMenuAnimationController(transitionType: .presenting)
       }
   
       func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
           return PopUpMenuAnimationController(transitionType: .dismissing)
       }
   }
   

   和

   class PopUpMenuAnimationController: NSObject, UIViewControllerAnimatedTransitioning {
       enum TransitionType {
           case presenting
           case dismissing
       }
   
       let transitionType: TransitionType
   
       init(transitionType: TransitionType) {
           self.transitionType = transitionType
           super.init()
       }
   
       func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
           return 1
       }
   
       func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
           let containerView = transitionContext.containerView
           guard let toVC = transitionContext.viewController(forKey: .to),
               let fromVC = transitionContext.viewController(forKey: .from) else { return }
   
           switch transitionType {
           case .presenting:
               containerView.addSubview(toVC.view)
   
               var rect = fromVC.view.bounds
               let menuHeight = fromVC.view.bounds.height / 2
               rect.origin.y += fromVC.view.bounds.height
               rect.size.height = menuHeight
               toVC.view.frame = rect
               toVC.view.alpha = 0
   
               UIView.animate(withDuration: 0.4, delay: 0, options: [.curveEaseOut], animations: {
                   rect.origin.y = menuHeight
                   toVC.view.frame = rect
                   toVC.view.alpha = 1
               }, completion: { _ in
                   transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
               })
   
           case .dismissing:
               UIView.animate(withDuration: 0.4, delay: 0, options: [.curveEaseOut], animations: {
                   var rect = fromVC.view.frame
                   rect.origin.y = toVC.view.bounds.height
                   fromVC.view.frame = rect
                   fromVC.view.alpha = 0
               }, completion: { _ in
                   transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
               })
           }
       }
   }
   

   这将转换委托和动画控制器与视图控制器分离，并允许您在需要时将其与其他视图控制器一起使用。

   请注意，我对 to 的参数也更加小心completeTransition。一旦开始使用交互式过渡，您可能会支持可取消的过渡。