IOS animation does not reset when replaying

Question

I have a very simple animation block that performs the following animation:

(tap the image if the animation does not play)

func didTapButton() {
  // reset the animation to 0
  centerYConstraint.constant = 0
  superview!.layoutIfNeeded()

  UIView.animate(
    withDuration: 1,
    animations: {
      // animate the view downwards 30 points
      self.centerYConstraint.constant = 30
      self.superview!.layoutIfNeeded()
  })
}

Everything is fine when I play the animation myself. It resets to position 0, and then revives 30 points.

The problem is that the user briefly presses the button several times in a row (i.e., in the middle of the current animation). Each time the user clicks the button, I expect it to be reset to position 0, and then go down 30 points. Instead, I get the following:

(tap the image if the animation does not play)

He clearly travels more than 30 points. (Closer to 120 points.)

Why is this happening, and how can I "reset" the animation correctly so that it does not exceed 30 points?

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• "" 0, 0 superview!.layoutIfNeeded.

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Answer 1

. removeAllAnimations() , .

@IBAction func didTapButton(_ sender: Any) {
    animatedView.layer.removeAllAnimations()

    centerYConstraint.constant = 0
    view.layoutIfNeeded()

    centerYConstraint.constant = 30
    UIView.animate(withDuration: 2) {
        self.view.layoutIfNeeded()
    }
}

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Answer 2

, , , reset .

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