淡出 in/out 一个 UILabel

Question

我的堆栈视图包含 2 个标签。我想为隐藏过程设置动画，例如当其中一个标签被隐藏时给它一个淡出动画，或者当其中一个标签未隐藏时给它一个淡入淡出动画。我该怎么做？

Answer 1

    let flash = CABasicAnimation(keyPath: "opacity")
    flash.duration = 0.5
    flash.fromValue = 1
    flash.toValue = 0.1
    flash.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
    flash.autoreverses = true
    flash.repeatCount = 3

    la1.layer.add(flash, forKey: nil)

Answer 2

您应该为 label 的 alpha 添加动画。

UIView.animate(withDuration: 1, animations: {
    disclaimerLabel.alpha = 0
}