ios - 如何在 Swift 中通过按下按钮来遍历函数

Question

我正在学习 swift 并构建 ARApp，但似乎无法理解如何在每次按下单独的按钮时迭代几个函数。我已经创建了 3 个内置动画的功能，我想按下按钮一次并激活 funcAnimation#1，然后再次点击按钮继续 funcAnimation#2 等等。

@IBAction func nextAnimation(_ sender: UIButton) {
funcAnimation#1()
funcAnimation#2()
funcAnimation#3()
}

当然这里的问题是它们都同时激活。我只想对每次按下的按钮进行迭代。此外，我还希望有一个 backButton 将当前动画反转为上一个动画。我在 Apple 的文档中读到有一个 addTarget 方法，但我不明白它是如何工作的或如何实现它。请帮忙!

Answer 1

你的代码应该是这样的:

// You can define this variable globally...
var counter = 0
@IBAction func nextAnimation(_ sender: UIButton) {
    if (counter == 0) {
        funcAnimation1()
        // Increase counter count by 1 and you can add this line to completion of animation.
       // You can also disable your button interaction until your animation gets complete and that way you can handle your UI
        count += 1
    }
    else if (counter == 1) {
        funcAnimation2()
         // Increase counter count by 1 and you can add this line to completion of animation.
        count += 1
    }
    else if (counter == 2) {
        funcAnimation3()
        // set your counter to 0 again to loop through your animation.
        counter = 0
    }
}

你的后退 Action 应该是这样的:

@IBAction func backAnimation(_ sender: UIButton) {
    if (counter == 0) {
        funcAnimation1()
        // set your counter to 2 again to loop through your animation.
        count = 2
    }
    else if (counter == 1) {
        funcAnimation2()
        // decrease counter count by 1 and you can add this line to completion of animation.
        // You can also disable your button interaction until your animation gets complete and that way you can handle your UI
        count -= 1
    }
    else if (counter == 2) {
        funcAnimation3()
       // decrease counter count by 1 and you can add this line to completion of animation.
        count -= 1
    }
}