Question

我有一个UIView，我希望在10秒内将不透明度设置为0。但是，动画应该在7.5秒后开始。这是因为我首先动画帧变换，UIView应该只淡出动画的最后1/4持续时间。这是我的尝试：

override func viewDidLoad() {
    let x = UIView()
    view.addSubview(x)
    x.frame = CGRect(x: 100, y: 100, width: 100, height: 100)
    x.backgroundColor = .black

    let animation = CABasicAnimation(keyPath: "opacity")
    animation.timingFunction = CAMediaTimingFunction(controlPoints: 0, 0, 0, 1)
    animation.fromValue = 1
    animation.toValue = 0
    animation.duration = 10
    animation.fillMode = kCAFillModeForwards

    x.layer.add(animation, forKey: "opacity")

}

UIView瞬间淡出。如何使用mediaTimingFunction延迟它？

Answer 1

将持续时间设置为2.5秒，并在开始帧动画后7.5秒开始动画

animation.beginTime = CACurrentMediaTime() + 7.5

具有不透明度动画的CAMediaTimingFunction

1 个答案: