如何将推特弹跳动画插入标签栏

Question

我有以下代码：

import UIKit
class AnimatedTabBarController: UITabBarController {
private var bounceAnimation: CAKeyframeAnimation = {
let bounceAnimation = CAKeyframeAnimation(keyPath: "transform.scale")
bounceAnimation.values = [1.0, 1.4, 0.9, 1.02, 1.0]
bounceAnimation.duration = TimeInterval(0.3)
bounceAnimation.calculationMode = CAAnimationCalculationMode.cubic
return bounceAnimation
}()
override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
// find index if the selected tab bar item, then find the corresponding view and get its image, the view position is offset by 1 because the first item is the background (at least in this case)
guard let idx = tabBar.items?.firstIndex(of: item), tabBar.subviews.count > idx + 1, let imageView = tabBar.subviews[idx + 1].subviews.first as? UIImageView else {
return
}
imageView.layer.add(bounceAnimation, forKey: nil)
}
}

当您单击图标时，我正在尝试创建推特反弹动画，尽管此代码没有执行任何操作。有人知道我做错了什么吗？

Answer 1

我忘了为我的标签栏控制器设置类