ios - 当一个 UIButton 被点击时，你如何让它变大，然后使用 Swift 3 回到以前/正常的大小？

Question

这是我当前的代码:

@IBAction func buttonTap(_ sender: Any) {
    if time >= 0 && gameStarted == true {
        score = score + 1
    }
}

除了增加分数，我如何让按钮变大，然后使用 Swift 3 恢复到正常大小？

Answer 1

如果您还没有，请为您的按钮创建一个 socket ，以便您可以访问它:

@IBOutlet weak var button: UIButton!

这是一个基本动画，它将按钮增加到其原始大小的两倍，然后将其放回原处。将此代码放入您的 buttonTap功能。

注意我将背景颜色设置为白色，然后是深灰色，然后又是白色，这样更容易看到发生了什么。这不是必需的。您可以根据需要调整速度和效果。

self.button.backgroundColor = UIColor.white

// save the original size and location of the button so we can restore it later    
let originalFrame = self.button.frame

// save the background color, too
let originalBackgroundColor = self.button.backgroundColor

UIView.animate(withDuration: 1.0, delay: 0, options: UIViewAnimationOptions.curveEaseInOut, animations: {

    // make the button grow to twice its original size
    self.button.frame.size.height = self.button.frame.size.height * 2
    self.button.frame.size.width = self.button.frame.size.width * 2

    // adjust the button's x,y coordinates so it appears to stay in place
    self.button.frame.origin.x = self.button.frame.origin.x - (self.button.frame.size.width / 4)
    self.button.frame.origin.y = self.button.frame.origin.y - (self.button.frame.size.height / 4)

    // change the background color so it's easier to see what's happening - not required
    self.button.backgroundColor = UIColor.darkGray

}) { (finished: Bool) in
    // after the previous animation finishes, restore the button to its original state
    UIView.animate(withDuration: 1.0, animations: {
        self.button.frame = originalFrame
        self.button.backgroundColor = originalBackgroundColor
    })    
}

编辑:@Tim 建议使用 animateKeyframes 对动画进行排序的更好方法.以下是您将如何执行此操作，将调用替换为 UIView.animate (效果是一样的):

UIView.animateKeyframes(withDuration: 2.0, delay: 0, options: UIViewKeyframeAnimationOptions.calculationModeLinear, animations: {

    // make the button grow and become dark gray
    UIView.addKeyframe(withRelativeStartTime: 0.0, relativeDuration: 0.5) {
        self.button.frame.size.height = self.button.frame.size.height * 2
        self.button.frame.size.width = self.button.frame.size.width * 2

        self.button.frame.origin.x = self.button.frame.origin.x - (self.button.frame.size.width / 4)
        self.button.frame.origin.y = self.button.frame.origin.y - (self.button.frame.size.height / 4)

        self.button.backgroundColor = UIColor.darkGray
    }

    // restore the button to original size and color
    UIView.addKeyframe(withRelativeStartTime: 0.5, relativeDuration: 0.5) {
        self.button.frame = originalFrame
        self.button.backgroundColor = originalBackgroundColor
    }
}, completion: nil)