Swift 你怎么做连续动画？

我想做连续的动画，像一个接一个，而不是循环或一次一个。编码时它是什么样子的

示例：100%不透明度时淡入，20%不透明度时淡出，80%时淡入，10%时淡出。。。因此，像一个脉冲，然后在0%改变标签文本并做相反的操作（基本上与图片相同，只是每次我尝试使其逐渐淡出-它会破坏整个动画）

gif显示的是它的当前状态，而不是我迄今为止尝试过的不起作用的状态

import UIKit

    class Belief2ViewController: UIViewController {
        @IBOutlet var negBeliefLabelGlower: UILabel!
        @IBOutlet var posBeliefLabelGlower: UILabel!
        @IBOutlet var labelNegBeliefFinal: UILabel!
        @IBOutlet var startButton: UIButton!
    
    
    
    
    
    
    
    //PASSING INFO
       var negBeliefLabelGlowerText = String()
    var posBeliefLabelGlowerText = String()
        
        

        override func viewDidLoad() {
            super.viewDidLoad()
            
            
    //PASSING INFO
           negBeliefLabelGlower.text = negBeliefLabelGlowerText
            posBeliefLabelGlower.text = posBeliefLabelGlowerText
        
            
            
            //PASSING INFO
                    
                    labelNegBeliefFinal.text = negBeliefLabelGlowerText
            //GLOW
                 labelNegBeliefFinal.UILableTextShadow(color: UIColor.systemTeal)
                
                
            //AniamtionOpacityLOOP
            labelNegBeliefFinal.alpha = 0.3
    //                            UIView.animate(withDuration: 5, animations: {self.labelNegBeliefFinal.alpha = 100}, completion: { _ in self.labelNegBeliefFinal.alpha = 90;})
                UIView.animate(withDuration: 6, delay: 0, options: [.autoreverse, .repeat], animations: { self.labelNegBeliefFinal.alpha = 100 })
                
            
            
             //AnimationBreathSizeLOOP
            UIView.animate(withDuration: 6, delay: 0, options: [.autoreverse, .repeat], animations: { self.labelNegBeliefFinal.transform = CGAffineTransform(scaleX: 1.3, y: 1.3) })
            
        }
    
    
    @IBAction func startButtonPress(_ sender: Any) {
        
        //self.labelNegBeliefFinal.text = self.posBeliefLabelGlowerText
//        UIView.animate(withDuration: 10, animations: {self.labelNegBeliefFinal.alpha = 0}, completion: { _ in self.labelNegBeliefFinal.text = self.posBeliefLabelGlowerText;})
        UIView.animate(withDuration: 10, delay: 0, animations: {self.labelNegBeliefFinal.alpha = 0}, completion: { _ in
                        self.labelNegBeliefFinal.text = self.posBeliefLabelGlowerText ;})
        //
        
    
    }
    
    
}
//GLOW
extension UILabel {
   func UILableTextShadow1(color: UIColor){
    textColor = UIColor.systemTeal
   layer.shadowColor = UIColor.systemTeal.cgColor
      layer.masksToBounds = false
    layer.shadowOffset = .zero
    layer.shouldRasterize = true
     layer.rasterizationScale = UIScreen.main.scale
      layer.shadowRadius = 5.0
      layer.shadowOpacity = 5.0
    }
    
}

编辑

好的，所以使用关键帧作为建议是一个完美的建议 但我遇到了一点问题。我无法键入要更改的标签文本

UIView.animateKeyframes(withDuration: 15.0,
                                    delay: 0.0,
                                            options: [],
                                            animations: {
                                                
                                                UIView.addKeyframe(withRelativeStartTime: 1,
                                    relativeDuration: 0.0,
                                    animations: { self.labelNegBeliefFinal.text = self.posBeliefLabelGlowerText })
                    },
                                            completion: nil)

---

因此，我无法将标签合并到关键帧动画中，所以我只是设置了捆更改的延迟，并进行了一些调整，但下面是我的想法

//CHANGE LABEL ON TIMER
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 13.5) 
{ [self] in
self.labelNegBeliefFinal.text = self.posBeliefLabelGlowerText
}
               
            
        
        
        
        
        
        

这是光晕循环和大小循环，和之前一样，与吐温无关

//AniamtionGlowLOOP
       
UIView.animate(withDuration: 6, delay: 0, options: [.autoreverse, .repeat], 
animations: { self.labelNegBeliefFinal.layer.shadowOpacity = 5.0 })

        
        
//AnimationBreathSizeLOOP
UIView.animate(withDuration: 6, delay: 0, options: [.autoreverse, .repeat], 
animations: { self.labelNegBeliefFinal.transform = CGAffineTransform(scaleX: 
1.3, y: 1.3) })
        
// }

这是我想出的tween代码，感谢Matt指出了正确的方向。我不知道你能在SwiftUI玩tween。有一件事让我很反感，如果持续时间是30秒，相对持续时间被设置为0.5等于15秒，因为它是30秒的0.5。我的一些孩子似乎不起作用，因为我没有意识到这一点

UIView.animateKeyframes(withDuration: 30.0,
                                delay: 0,
                                options: [ ],
                                animations: {

                                
                                    UIView.addKeyframe(withRelativeStartTime: 
0,
                   relativeDuration: 0.5,
                   animations: { self.labelNegBeliefFinal.alpha = 0 })
                                    
                                    
                                    UIView.addKeyframe(withRelativeStartTime: 
0.5,
                   relativeDuration: 0.5,
                   animations: { self.labelNegBeliefFinal.alpha = 1 })
                                    

        },
                                completion: nil)
    
        
    

    }


}

我从另一个帖子得到的发光风格

//GLOW
extension UILabel {
func UILableTextShadow1(color: UIColor){
textColor = UIColor.systemTeal
layer.shadowColor = UIColor.systemTeal.cgColor
layer.masksToBounds = false
layer.shadowOffset = .zero
layer.shouldRasterize = true
layer.rasterizationScale = UIScreen.main.scale
layer.shadowRadius = 5.0
layer.shadowOpacity = 00.7
    }





}

---

看看关键帧动画。希望我能给你评分，让你回答最好的一个，但是我还没有这个选项。我相信如果你解决了这个问题，请随意回答你自己的问题！完全合法并受到鼓励。