ios - swift:一段时间后重复动画

Question

我有这个动画:

override func viewDidLoad() {
        super.viewDidLoad()
_ = Timer.scheduledTimer(timeInterval: 15, target: self, selector: #selector(self.callingFunction), userInfo: nil, repeats: true)
}

@objc func callingFunction(){
        let image0:UIImage = UIImage(named: "next0.png")!
        let image1:UIImage = UIImage(named: "next1.png")!
        let image2:UIImage = UIImage(named: "next2.png")!
        let image3:UIImage = UIImage(named: "next3.png")!
        let image4:UIImage = UIImage(named: "next4.png")!
        let image5:UIImage = UIImage(named: "next5.png")!
        let image6:UIImage = UIImage(named: "next6.png")!
        let image7:UIImage = UIImage(named: "next7.png")!

        nextButton.setImage(image0, for: .normal)
        nextButton.imageView!.animationImages = [image0, image1, image2, image3, image4, image5, image6, image7]
        nextButton.imageView!.animationDuration = 1.0
        nextButton.imageView!.startAnimating()
    }

我需要每 15 秒重复一次这个动画。但是这个动画在 15 秒后开始，接下来每 1 秒执行一次。

Answer 1

只是更新你的代码

只需要设置 animationRepeatCount = 1(这将有助于图像更改一次停止)，当计时器达到 15 秒时再次调用您的调用函数。

override func viewDidLoad() {
    super.viewDidLoad()
    /// You need to take class object here for timer, when viewWillDisapper called you need to invalidate timer other wise you will fase memory issues
    self.timer = Timer.scheduledTimer(timeInterval: 15, target: self, selector: #selector(self.timerTimeUp), userInfo: nil, repeats: true)
}

@objc func timerTimeUp() {
    self.callingFunction()
}

func callingFunction(){
    let image0:UIImage = UIImage(named: "next0.png")!
    let image1:UIImage = UIImage(named: "next1.png")!
    let image2:UIImage = UIImage(named: "next2.png")!
    let image3:UIImage = UIImage(named: "next3.png")!
    let image4:UIImage = UIImage(named: "next4.png")!
    let image5:UIImage = UIImage(named: "next5.png")!
    let image6:UIImage = UIImage(named: "next6.png")!
    let image7:UIImage = UIImage(named: "next7.png")!

    nextButton.setImage(image0, for: .normal)
    nextButton.imageView!.animationImages = [image0, image1, image2, image3, image4, image5, image6, image7]
    nextButton.imageView!.animationDuration = 1.0
    nextButton.imageView!.animationRepeatCount = 1
    nextButton.imageView!.startAnimating()
}

更新代码

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    self.invalidateTimer()
}

func invalidateTimer() {
   if self.timer != nil {
      self.timer.invalidate()
      self.timer = nil
   }
}

每当 View 关闭/消失时，您都可以调用 invalidateTimer() 方法。

希望对您有所帮助。