動畫兩個數字之間的 UILabel 文本？

Question

我是 iPhone 和 Mac 編程的新手（之前為 Windows 開發），我有一個問題：

如何在兩個數字之間為UILabel的text屬性設置動畫，例如在緩出樣式中從5到80 ？ CoreAnimation嗎？ 我在谷歌上搜索了一個小時，但沒有找到任何解決我問題的方法。 我想要的是：讓用戶為一個簡單的游戲賺錢。 當它從50到100或類似沒有動畫的東西時，它看起來不是很好。

任何人都知道如何做到這一點？

謝謝！

Answer 1

您可以使用自動轉換。 它運行良好：

// 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 myLabel 已顯示，則此代碼有效。 如果不是 myLabel.layer 將為 nil 並且動畫將不會添加到對象中。

---

在Swift 4 中，這將是：

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

Answer 2

它運作良好！

目標-C

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

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

} completion:nil];

斯威夫特 2

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

斯威夫特 3、4、5

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

Answer 3

我找到了一個很棒的引擎，可以使用稱為PRTween的各種不同的計時函數來補間值。 安裝這些類並按照以下方式創建一些代碼：

- (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];
}

對我有用。 :)

Answer 4

如果您希望它用新數字將前一個數字推開（例如股票代碼或其他東西）來上下計數：

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

另一個簡單的選擇

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)))"
            }
        }
    }
}