重置UIProgressView并立即开始使用Swift 3

Question

我有一个像Snapchat和Instagram故事一样的进度视图。进度视图到达最后或点击按钮后，我的内容会发生变化。

我正在重置内容更改时的进度视图。一切都按预期工作，而没有干预。但是，当点击下一个按钮时，进度视图不会再次开始，直到其他循环执行。您可以快速看到video here。

我碰到this question出来，而我研究，我也有同样的情况，但我无法适用的原则与SWIFT 3.

这里一个新手是我的代码，任何帮助，将不胜感激：

func startTimer(){ 
    self.timer = Timer.scheduledTimer(timeInterval: 3, target: self, selector: #selector(myVievController.nextItem), userInfo: nil, repeats: false) 
} 

func updateProgressBar() { 
    self.progressView.setProgress(1.0, animated: false) 
    UIView.animate(withDuration: 2.8, animations: {() -> Void in 
     self.progressView.layoutIfNeeded() 
    }, completion: { finished in 
     if finished { 
      self.progressView.setProgress(0, animated: false) 
     } 
    }) 
} 

func nextItem(){ 
    // ... 
    self.updateUI(item: self.myCurrentItem) 
    // ... 
} 

func updateUI(item:MyItem){ 
    self.updateProgressBar() 
    self.timer.invalidate() 
    self.startTimer() 

    // Clear old item and fill new values etc... 
} 

@IBAction func nextButtonPressed(_ sender: UIButton) { 
    self.nextItem() 
} 

Answer 1

你可能需要这样的更新您的进度条：self.progressView.setProgress(0, animated: false)

func updateProgressBar() { 
    DispatchQueue.main.async { 
     self.progressView.setProgress(0.1, animated: false) 
    } 
    if self.progressView.Progress == 1.0 { 
     self.timer.invalidate() 
    } else { 
     self.timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(myVievController.updateProgressBar), userInfo: nil, repeats: false) 
    } 
} 

然后你就可以invalidat E中的计时器和停止更新，当你在100％

Answer 2

也可以用子做到这一点：

class HelloWorld: UIProgressView { 

    func startProgressing(duration: TimeInterval, resetProgress: Bool, completion: @escaping (Void) -> Void) { 
     stopProgressing() 

     // Reset to 0 
     progress = 0.0 
     layoutIfNeeded() 

     // Set the 'destination' progress 
     progress = 1.0 

     // Animate the progress 
     UIView.animate(withDuration: duration, animations: { 
      self.layoutIfNeeded() 

     }) { finished in 
      // Remove this guard-block, if you want the completion to be called all the time - even when the progression was interrupted 
      guard finished else { return } 

      if resetProgress { self.progress = 0.0 } 

      completion() 
     } 
    } 

    func stopProgressing() { 
     // Because the 'track' layer has animations on it, we'll try to remove them 
     layer.sublayers?.forEach { $0.removeAllAnimations() } 
    } 
} 

可以通过调用-startProgressing()时，你永远需要重新启动progressView使用从头开始。该完成被调用的时候它有完成动画，这样你就可以改变看法等

使用的例子：

progressView.startProgressing(duration: 5.0, resetProgress: true) { 
    // Set the next things you need... change to a next item etc. 
}