我有一个 viewController，它有一个 TableView 和一个 accessoryType 为 detailbutton 的单元格。 当按下 accessoryType 时，我会呈现一个带有文本的半透明 View 。

我希望此 View 以特定方式显示，因此我创建了一个自定义 View Controller 。

但是，尝试在 detailbutton 中运行该 viewController 是行不通的。

我的部分代码:

//Defined in the class
let customTransitionManager = TransitionManager()

//in tableView cellForRowAtIndexPath
if (tableView == continent){
        let cell:UITableViewCell = UITableViewCell(style:UITableViewCellStyle.Default, reuseIdentifier: "continentSelector")
        cell.textLabel?.text = "Continent"
        cell.accessoryType = UITableViewCellAccessoryType.DetailButton;
        return cell


func tableView(tableView: UITableView, accessoryButtonTappedForRowWithIndexPath indexPath: NSIndexPath){
    println(indexPath)
    let detailController = storyboard?.instantiateViewControllerWithIdentifier("detailButtonStoryBoard") as? detailedView
    detailController?.modalPresentationStyle = .Custom
    detailController?.transitioningDelegate = customTransitionManager;
    presentViewController(detailController!, animated: true, completion: nil)
}

运行此代码会出现以下错误:

fatal error: unexpectedly found nil while unwrapping an Optional value

以下突出显示:

-> 0x100209cf0 <function signature specialization <Arg[0] = Exploded, Arg[1] = Exploded, Arg[2] = Dead, Arg[3] = Dead> of Swift._fatalErrorMessage (Swift.StaticString, Swift.StaticString, Swift.StaticString, Swift.UInt) -> ()+44>: brk    #0x1

最佳答案

我看到有两个地方可以使用 nil 值。第一个是在索引路径处的行的单元格中，但这不太可能。第二个也是更有可能的一个是您在呈现 detailContoller 时尝试解包的地方。您是否确认您正在从 Storyboard 中取回 Controller ？

更新:我在评论中提出的解决方案格式很糟糕，这里有一个更好的格式

找到解决方案使用 segue 而不是手动呈现 Controller 。

1. 从 didSelectRowAtIndexPath 调用 performSegue

2. 在 prepareForSegue 方法中放入:

   let toViewController = segue.destinationViewController as UIViewController
   toViewController.transitioningDelegate = self.customTransitionManager`
   

本教程的全部功劳:http://mathewsanders.com/animated-transitions-in-swift/#custom-transition-animations

更新 2:下载您的项目并使其运行。以下是我所做的更改:

1. 我在牛仔裤 Controller 和细节 Controller 之间添加了一个模态转场。我称之为“DetailSegue”

2. 我更新了 jeans.swift 文件的 accessoryButtonTappedForRowWithIndexPath 方法如下:

   func tableView(tableView: UITableView, accessoryButtonTappedForRowWithIndexPath indexPath: NSIndexPath){
       println(indexPath)
       self.performSegueWithIdentifier("DetailSegue", sender: self)
   }
   

3. 然后我按如下方式更新了 TransitionManger animateTransition 函数，基本上使往返 View 成为可选的并适本地处理 nil

   func animateTransition(transitionContext: UIViewControllerContextTransitioning) {
       //get reference to our FROM View, To View, and container view that we should perform the transition in
       let container = transitionContext.containerView()
   
       let fromView = transitionContext.viewForKey(UITransitionContextFromViewKey)
       let toView = transitionContext.viewForKey(UITransitionContextToViewKey)
   
       //setup from 2D transform that we'll use in the animation
       let offScreenRight = CGAffineTransformMakeTranslation(container.frame.width, 0)
       let offScreenLeft = CGAffineTransformMakeTranslation(-container.frame.width, 0)
   
       //start the view to the right of the screen 
       toView?.transform = offScreenRight
   
       //add both the views to our view controller
       if toView != nil {
           container.addSubview(toView!)
       }
   
       if fromView != nil {
           container.addSubview(fromView!)
       }
   
       // get the duration of the animation
       let duration = self.transitionDuration(transitionContext)
   
       //perform the animation
   
       UIView.animateWithDuration(duration, delay: 0.0, options: nil, animations: {
           fromView?.transform = offScreenLeft
           toView?.transform = CGAffineTransformIdentity
           }, completion: { finished in transitionContext.completeTransition(true)})
   }
   

这是最终结果的截屏视频:http://screencast.com/t/2mC07BLCC

我希望这能帮助您推进项目。

关于ios - 快速向 presentViewController 添加自定义转换，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/28798773/