（Swift）淡入淡出标签[重复]

Posted 2023-03-16

【中文标题】（Swift）淡入淡出标签[重复]

【英文标题】：(Swift) Fade-In and Out a Label [duplicate]

【发布时间】：2016-08-17 04:16:49

【问题描述】：

当标签出现在屏幕上时，我正在尝试淡入淡出。目前，我只是使用

隐藏它

button.hidden = true

并使用 false 取消隐藏它。我想用淡入淡出来动画这个过程，因为这样看起来更平滑。感谢您的帮助！

这是我正在使用的出现错误的代码。 http://imgur.com/a/HI4eg

class ViewController: UIViewController 
@IBOutlet weak var yeah: UILabel!

override func viewDidLoad() 
    super.viewDidLoad()

    UIView.animateWithDuration(1.0, delay: 0.0, options: .CurveEaseOut, animations: 
        self.yeah.alpha = 0.0
        , completion: 
            (finished: Bool) -> Void in

            //Once the label is completely invisible, set the text and fade it back in
            self.yeah.text = "your Text "

            // Fade in
            UIView.animateWithDuration(1.0, delay: 0.0, options: .CurveEaseIn, animations: 
                self.yeah.alpha = 1.0
                , completion: 
                    (finished: Bool) -> Void in

                    //Once the label is completely invisible, set the text and fade it back in
                    self.yeah.text = "your Text "

                    // Fade in
                    UIView.animateWithDuration(1.0, delay: 0.0, options: .CurveEaseIn, animations: 
                        self.yeah.alpha = 1.0
                        , completion:nil )




            )
    // Do any additional setup after loading the view, typically from a nib.


override func didReceiveMemoryWarning() 
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.

【问题讨论】：

您是否正在寻找具有淡出效果的隐藏和具有淡入效果的显示？由于默认隐藏是不可动画的？

【参考方案1】：

如andrew bancroft's blog中所述

     // Move our fade out code from earlier
    UIView.animateWithDuration(1.0, delay: 0.0, options: .CurveEaseOut, animations: 
        self.yourLabel.alpha = 0.0
        , completion: 
            finished in

            if finished 
                //Once the label is completely invisible, set the text and fade it back in
                self.yourLabel.text = "your Text "

                // Fade in
                UIView.animateWithDuration(1.0, delay: 0.0, options: .CurveEaseIn, animations: 
                    self.yourLabel.alpha = 1.0
                , completion: nil)
            
    )

修改后的答案

    UIView.animateWithDuration(1.0, delay: 0.0, options: .CurveEaseOut, animations: 
        self.yourLabel.alpha = 0.0
        , completion: 
            finished in

            if finished 
                //Once the label is completely invisible, set the text and fade it back in
              self.yourLabel.text = "your Text "

                // Fade in
                UIView.animateWithDuration(1.0, delay: 0.0, options: .CurveEaseIn, animations: 
                  self.yourLabel.alpha = 1.0
                    , completion: 
                        finished in

                        if finished 
                            //Once the label is completely invisible, set the text and fade it back in
                              self.yourLabel.text = "your Text "

                            // Fade in
                            UIView.animateWithDuration(1.0, delay: 0.0, options: .CurveEaseIn, animations: 
                                self.yourLabel.alpha = 0.0
                                , completion: nil)
                        
                )
            
    )

【讨论】：

您应该将if finished 添加到您的闭包中。完成块可能在未完成时被调用。

如果你引用某人的代码，最好先写名字作为参考。

@DipenPanchasara - 当然，我的兄弟，你能修改我按照你的方式回答的答案

@Anbu.Karthik 谢谢。

@DipenPanchasara - tanx 伙计，我跟着我的油炸了美好的一天