swift - UIImageView 的延迟时间

Question

当我将图像索引从collectionView发送到另一个全屏显示该图像的viewController时，我有图像数组，并且我让用户能够在图像之间滑动，但滑动时出现问题更改时图像之间的滑动速度非常快，当图像更改时，我需要延迟 UIImageView 上的时间，对此问题有任何解决方案吗？

下面的代码:

var ImageIndex:Int = 0 // this is index image which i send it from previous view controller
var arrayOfUrlImageLarge:[String] = []// this array which contain all the url of images

覆盖 func viewDidLoad() {

    super.viewDidLoad()

imageView = UIImageView(图像: UIImage(contentsOfFile: arrayOfUrlImageLarge[ImageIndex]))

    imageView.contentMode = UIViewContentMode.ScaleAspectFill

     let swipeGestureRight = UISwipeGestureRecognizer(target: self, action: #selector(ShowImageViewController.swipe(_:)))
    swipeGestureRight.direction = .Right
    let swipeGestureLeft = UISwipeGestureRecognizer(target: self, action: #selector(ShowImageViewController.swipe(_:)))
    swipeGestureLeft.direction = .Left
    self.imageView.addGestureRecognizer(swipeGestureLeft)
    self.imageView.addGestureRecognizer(swipeGestureRight)
 }

func swipe(手势:UISwipeGestureRecognizer){

    if gesture.direction == .Right {

        if ImageIndex == 0 {
            imageView.image = UIImage(data: NSData(contentsOfFile: arrayOfUrlImageLarge[ImageIndex])!)
        }else {
            ImageIndex = ImageIndex - 1
            imageView.image = UIImage(data: NSData(contentsOfFile: arrayOfUrlImageLarge[ImageIndex])!)
        }
    }
    if gesture.direction == .Left{

        if ImageIndex >= arrayOfUrlImageLarge.count {
            ImageIndex = arrayOfUrlImageLarge.count - 1
            imageView.image = UIImage(data: NSData(contentsOfFile: arrayOfUrlImageLarge[ImageIndex])!)
        }else {
            ImageIndex = ImageIndex + 1
            if ImageIndex >= arrayOfUrlImageLarge.count {
                return
            }
            imageView.image = UIImage(data: NSData(contentsOfFile: arrayOfUrlImageLarge[ImageIndex])!)

        }
    }
}

谢谢

Answer 1

func swipe(gesture:UISwipeGestureRecognizer){

   let delay = 4.5 * Double(NSEC_PER_SEC)
   let time = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
   dispatch_after(time, dispatch_get_main_queue()) {

       if gesture.direction == .Right {

        if ImageIndex == 0 {
           imageView.image = UIImage(data: NSData(contentsOfFile: arrayOfUrlImageLarge[ImageIndex])!)
        }
        else {
          ImageIndex = ImageIndex - 1
          imageView.image = UIImage(data: NSData(contentsOfFile: arrayOfUrlImageLarge[ImageIndex])!)
        }
       }
      if gesture.direction == .Left{

        if ImageIndex >= arrayOfUrlImageLarge.count {
           ImageIndex = arrayOfUrlImageLarge.count - 1
           imageView.image = UIImage(data: NSData(contentsOfFile: arrayOfUrlImageLarge[ImageIndex])!)
       }
       else {
         ImageIndex = ImageIndex + 1
         if ImageIndex >= arrayOfUrlImageLarge.count {
            return
         }
        imageView.image = UIImage(data: NSData(contentsOfFile: arrayOfUrlImageLarge[ImageIndex])!)
        }

      }
   }
}