Question

我是iPhone和Mac编程的新手（之前为Windows开发过），我有一个问题：

如何在两个数字之间设置text UILabel属性的动画，例如从 5 到 80 的Ease-Out风格？ CoreAnimation可以吗？我一直在Google上搜索一个小时，但我找不到解决问题的方法。我想要的是：为一个简单的游戏动画用户的钱。当它从 50 变为 100 或类似没有动画的情况时，它看起来不太好。

任何人都知道如何做到这一点？

谢谢！

Answer 1

您可以使用自动过渡。它运作得非常好：

// Add transition (must be called after myLabel has been displayed)
 CATransition *animation = [CATransition animation];
animation.duration = 1.0;
animation.type = kCATransitionFade;
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
[myLabel.layer addAnimation:animation forKey:@"changeTextTransition"];

// Change the text
myLabel.text = newText;

如果已经显示myLabel，则此代码有效。如果不是myLabel.layer将为nil并且动画将不会添加到对象中。

在 Swift 4 中将是：

let animation: CATransition = CATransition()
animation.duration = 1.0
animation.type = kCATransitionFade
animation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
myLabel.layer.add(animation, forKey: "changeTextTransition")

Answer 2

效果很好！

<强>目标C

[UIView transitionWithView:self.label 
                  duration:.5f 
                   options:UIViewAnimationOptionCurveEaseInOut | 
                           UIViewAnimationOptionTransitionCrossDissolve 
                animations:^{

    self.label.text = rand() % 2 ? @"111!" : @"42";

} completion:nil];

<强>夫特

UIView.transitionWithView(label, duration: 0.25, options: [.CurveEaseInOut, .TransitionCrossDissolve], animations: {
    self.label.text = (arc4random() % 2 == 0) ? "111" : "222"
}, completion: nil)

Answer 3

我找到了一个很棒的引擎，可以通过名为PRTween的各种不同的计时函数来补间值。安装类并沿着这些行创建一些代码：

- (IBAction)tweenValue
{
    [[PRTween sharedInstance] removeTweenOperation:activeTweenOperation];
    PRTweenPeriod *period = [PRTweenPeriod periodWithStartValue:0.0 endValue:100.0 duration:1.0];
    activeTweenOperation = [[PRTween sharedInstance] addTweenPeriod:period
                                                             target:self
                                                           selector:@selector(update:)
                                                     timingFunction:&PRTweenTimingFunctionCircOut];
}

- (void)update:(PRTweenPeriod*)period
{
    self.animatingView.center = CGPointMake(period.tweenedValue + 100.0, 200.0);
    self.valueLabel.text = [NSString stringWithFormat:@"%.2f", period.tweenedValue];
}

为我服务。：）

Answer 4

如果您希望它能够使用新号码推倒上一个号码（如股票代码或其他内容）：

let animation = CATransition()
animation.removedOnCompletion = true
animation.duration = 0.2
animation.type = kCATransitionPush
animation.subtype = newValue > value ? kCATransitionFromTop : kCATransitionFromBottom
animation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)
valueLabel.layer.addAnimation(animation, forKey:"changeTextTransition")

Answer 5

在Swift 2.0中，使用UIView.transitionWithView()方法：

UIView.transitionWithView(self.payPeriodSummaryLabel,
        duration: 0.2,
        options: [.CurveEaseInOut, .TransitionCrossDissolve],
        animations: { () -> Void in
            self.label.text = "your text value"
        }, completion: nil)

Answer 6

另一个简单的选择

extension UILabel {    
    func countAnimation(upto: Double) {
        let from: Double = text?.replace(string: ",", replacement: ".").components(separatedBy: CharacterSet.init(charactersIn: "-0123456789.").inverted).first.flatMap { Double($0) } ?? 0.0
        let steps: Int = 20
        let duration = 0.350
        let rate = duration / Double(steps)
        let diff = upto - from
        for i in 0...steps {
            DispatchQueue.main.asyncAfter(deadline: .now() + rate * Double(i)) {
                self.text = "\(from + diff * (Double(i) / Double(steps)))"
            }
        }
    }
}

在两个数字之间设置UILabel文本的动画？

6 个答案: