Swift3 Swift 3-使用数组向左滑动以更改标签

我是初学者，正在学习Swift 3，但如果使用数组，则无法使用

这是我的密码

如何编码，使标签仅从“hello1”更改为“hello2”，然后再次向左滑动至“hello3”。同时从“hello3”到“hello2”和“hello1”反向向右回扫。或者循环回到第一个

谢谢

class ChangeLabelViewController: UIViewController {

var helloArray = ["Hello1", "Hello2", "Hello3"]
var currentArrayIndex = 0


@IBOutlet weak var helloLabel: UILabel!


override func viewDidLoad() {
    super.viewDidLoad()

    let leftSwipe = UISwipeGestureRecognizer(target: self, action: #selector(ChangeLabelViewController.handleSwipes(sender:)))

    let rightSwipe = UISwipeGestureRecognizer(target: self, action: #selector(ChangeLabelViewController.handleSwipes(sender:)))

    leftSwipe.direction = .left
    rightSwipe.direction = .right

    view.addGestureRecognizer(leftSwipe)
    view.addGestureRecognizer(rightSwipe)

    helloLabel.text = helloArray[currentArrayIndex]
}

func handleSwipes(sender: UISwipeGestureRecognizer) {

    if sender.direction == .left {
        helloLabel.text = helloArray[currentArrayIndex + 1]


    }

    if sender.direction == .right {

    }
}

试试这个：

if sender.direction == .left {
    currentArrayIndex = (currentArrayIndex + 1) % 3
    helloLabel.text = helloArray[currentArrayIndex]
}

if sender.direction == .right {
    currentArrayIndex = (currentArrayIndex + 3 - 1) % 3 //if uInt
    helloLabel.text = helloArray[currentArrayIndex]
}

---

你也可以用下面的代码

func handleSwipes(sender: UISwipeGestureRecognizer) {

    if sender.direction == .left {

        if(currentArrayIndex < helloArray.count - 1)
        {
            currentArrayIndex += 1
            let indexPath = IndexPath(item: currentArrayIndex, section: 0)
            helloLabel.text = helloArray[indexPath.row]
        }
    }

    if sender.direction == .right {

        if(currentArrayIndex > 0)
        {
            currentArrayIndex -= 1
            if currentArrayIndex == -1
            {
                currentArrayIndex = 0
                let indexPath = IndexPath(item: currentArrayIndex, section: 0)
                helloLabel.text = helloArray[indexPath.row]
            }
            else {
                let indexPath = IndexPath(item: currentArrayIndex, section: 0)
                helloLabel.text = helloArray[indexPath.row]
            }
        }

    }

func handlesweeps（发送方：UISweepGestureRecognitor）{
如果sender.direction==.left{
如果（currentArrayIndex0）
{
currentArrayIndex-=1
如果currentArrayIndex==-1
{
currentArrayIndex=0
让indexPath=indexPath（项：currentArrayIndex，节：0）
helloLabel.text=helloArray[indexPath.row]
}
否则{
让indexPath=indexPath（项：currentArrayIndex，节：0）
helloLabel.text=helloArray[indexPath.row]
}
}
}

谢谢Simonly。这是我学到的很棒的技巧和教程。我会进一步消化代码。希望这能帮助你！：）@JimmyWongI按照代码进行操作，当运行到最后一个数组时，应用程序崩溃，因为“索引超出范围”谢谢你的指导。哦…现在你可以检查了。谢谢Jigar。代码工作得很好。我会尽力理解的。这是我的荣幸，Jimmy