Question

在一个视图中，我选择了一些图像，然后单击“完成”按钮，将这些图像传递到另一个视图（滚动视图），并导航到该视图。

在该滚动视图的viewDidLoad中，我将图像添加到滚动视图中，就像这样...

for i in 0..<images.count {
  let imageView = UIImageView()
  let x = self.view.frame.size.width * CGFloat(i)
  imageView.frame = CGRect(x: x, y: 0, width: self.view.frame.width, height: self.view.frame.height)
  imageView.contentMode = .scaleAspectFit
  imageView.image = images[i]

  scrollView.contentSize.width = scrollView.frame.size.width * CGFloat(i + 1)
  scrollView.addSubview(imageView)

  let backButton = UIBarButtonItem(title: "Back", style: UIBarButtonItem.Style.plain, target: self, action: #selector(self.goBack))
  navigationItem.leftBarButtonItem = backButton

  let cropButton = UIBarButtonItem(title: "Crop", style: UIBarButtonItem.Style.plain, target: self, action: #selector(self.crop))
  navigationItem.rightBarButtonItem = cropButton
}

现在，在此滚动视图的顶部，有一个名为“ CROP”的按钮，单击该按钮，我导航到某个视图，该视图是用于裁剪的界面（该界面是用于裁剪图像的库的一部分）。现在，在裁剪图像之后，我在该界面中单击“完成”按钮，这将导致调用此函数（该库本身的一部分）...

此功能为我提供了裁剪后的图像。

  func cropViewController(_ cropViewController: CropViewController, didCropToImage image: UIImage, withRect cropRect: CGRect, angle: Int) {
     print(image) --> This gives the cropped image

}

单击裁剪界面上的完成按钮时，我再次返回到滚动视图。为了获得更新的图像，即滚动视图中的裁剪图像，我尝试了类似的方法。

    func cropViewController(_ cropViewController: CropViewController, didCropToImage image: UIImage, withRect cropRect: CGRect, angle: Int) {

     croppedImage = image
    self.images[Int(currentPage)] = image // currentPage is the current index of scrollview 


    //Below lines of code are the same lines written in viewDidLoad
       for i in 0..<images.count {
          let imageView = UIImageView()
          let x = self.view.frame.size.width * CGFloat(i)
          imageView.frame = CGRect(x: x, y: 0, width: self.view.frame.width, height: self.view.frame.height)
          imageView.contentMode = .scaleAspectFit
          imageView.image =  self.images[i]

          scrollView.contentSize.width = scrollView.frame.size.width * CGFloat(i + 1)
          scrollView.addSubview(imageView)

          let backButton = UIBarButtonItem(title: "Back", style: UIBarButtonItem.Style.plain, target: self, action: #selector(self.goBack))
          navigationItem.leftBarButtonItem = backButton

          let cropButton = UIBarButtonItem(title: "Crop", style: UIBarButtonItem.Style.plain, target: self, action: #selector(self.crop))
          navigationItem.rightBarButtonItem = cropButton
        }

    }

现在，这确实为我提供了滚动视图中的更新图像。但是问题是滚动视图从第一张图像开始（即单击裁剪界面上的``完成''按钮时，我会进入滚动视图中图像列表中的第一张图像）。但是我想查看裁剪/更新的图像。

要实现此目标，我可以做些什么改变？

Answer 1

一旦您用编辑过的图片更新了滚动视图，请在currentPage方法末尾相对于cropViewController:更改滚动视图的内容偏移量，

let xPosition = scrollView.frame.size.width * CGFloat(currentPage) //or currentPage + 1 depends on your currentPage logic
scrollView.setContentOffset(CGPoint(x: xPosition, y: 0), animated: true)

裁剪后在滚动视图上显示更新的图像

1 个答案: