ios - 根据位置删除图像的ScrollView

Question

我制作了一个 ScrollView ，并制作了一个图像数组(稍后我将添加一个选项供用户将图像发布到该数组中，而 friend 的图像将填充到该数组中)并希望用户能够看到一张照片并跟踪它。

我创建了一个用于将照片添加到数组中的 for 循环，但是当我创建一个 if 语句来取出数组中的一个项目时，我得到了一个错误，因为我将从数组中删除图像 [i] 并且我有点知道为什么会这样，但想修复它。所以基本上我需要取出数组中的图像。
请帮助我，我还在学习。

class ViewController: UIViewController {

var imageArray = [UIImage]()

@IBOutlet weak var mainScrollView: UIScrollView!

override func viewDidLoad() {
    super.viewDidLoad()
    mainScrollView.frame = view.frame
    imageArray = [#imageLiteral(resourceName: "dubai6"), #imageLiteral(resourceName: "dubai2"), #imageLiteral(resourceName: "dubai7"), #imageLiteral(resourceName: "dubai4"), #imageLiteral(resourceName: "dubai3"), #imageLiteral(resourceName: "dubai5"), #imageLiteral(resourceName: "DigitalDrawingPreview"), #imageLiteral(resourceName: "denarus"), #imageLiteral(resourceName: "dubai1")]
    for i in 0..<imageArray.count  {
        let imageView = UIImageView()
        imageView.contentMode = .scaleAspectFit
        imageView.image = imageArray[i]
        let xPosition = self.view.frame.width * CGFloat(i)
        imageView.frame = CGRect(x: xPosition, y: 0, width: self.view.frame.width, height: self.mainScrollView.frame.height)

        mainScrollView.contentSize.width = mainScrollView.frame.width * CGFloat(i + 1)
        mainScrollView.addSubview(imageView)
    }
    for i in 0..<imageArray.count {
        if (i >= 2) {
            imageArray.remove(at: (i - 2))
        }
    }

    // Do any additional setup after loading the view, typically from a nib.
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
}

谢谢你们更好的程序员。

Answer 1

遍历数组时不能从数组中删除元素，因此必须使用临时数组

class ViewController: UIViewController {

var imageArray = [UIImage]()

@IBOutlet weak var mainScrollView: UIScrollView!

override func viewDidLoad() {
    super.viewDidLoad()
    mainScrollView.frame = view.frame
    imageArray = [#imageLiteral(resourceName: "dubai6"), #imageLiteral(resourceName: "dubai2"), #imageLiteral(resourceName: "dubai7"), #imageLiteral(resourceName: "dubai4"), #imageLiteral(resourceName: "dubai3"), #imageLiteral(resourceName: "dubai5"), #imageLiteral(resourceName: "DigitalDrawingPreview"), #imageLiteral(resourceName: "denarus"), #imageLiteral(resourceName: "dubai1")]
    for i in 0..<imageArray.count  {
        let imageView = UIImageView()
        imageView.contentMode = .scaleAspectFit
        imageView.image = imageArray[i]
        let xPosition = self.view.frame.width * CGFloat(i)
        imageView.frame = CGRect(x: xPosition, y: 0, width: self.view.frame.width, height: self.mainScrollView.frame.height)

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


    }
    let tempArr = imageArray
    for i in 0..<tempArr.count {
        if (i >= 2) { // Breakpoint here
            imageArray.remove(at: (i - 2))
        }

    }

    // Do any additional setup after loading the view, typically from a nib.
}



override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
}

使用 step over 遍历 for 循环的每一行直到它崩溃，然后通过将光标悬停在它上面或在控制台 po i 键入命令并输入当时打印 i 的值