Swift动画-执行序列

Question

I'm not entirely sure how to perform a sequence of animations. If I try this it normally skips to the last one in the function.

Let's say I want to move 2 UIImageView (side-by-side) 300 points upwards, then 2 UILabel (below the UIImageView ) 300 points upwards as well.

Then, I want the Label to count up from 1 to 10 -for example-.

Finally, once the label has counted to 10, I want the UIImageView and UILabel to move back down by 300 points.

    func moveLabelUP() {

    label.center = CGPoint(x: label.center.x - 300, y: label.center.y)

    UILabel.animate(withDuration: 5) {

        self.label.center = CGPoint(x: self.label.center.x + 300, y: self.label.center.y)

    func startLabelCountUp(){
    timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(updateLabel), userInfo: nil, repeats: true)
}

func updateLabel(){
    if self.current < elapsedTime {
        self.current += 1

        self.label.text = "\(self.current)"
    }else{
        self.timer.invalidate()
    }
}

How can I connect these chain of events?

How can I apply a delay to when the timer starts for each UILabel ?

I want the UIImageView to raise, the UILabel counts to 10, Then the UIImageView is lowered. This should repeated for the next UIImageView and UILabel to the right of the first ones.

Answer 1

This is the way I have been using it. It is just a basic concept but you will get an idea. For my case I was using it with constants.

UIView.animate(withDuration: duration, animations: { 

   // Your changes to the UI, eg. moving UIImageView up 300 points

   }) { (success) in

        // This executes when animation is completed
        // Create another animation here. It starts when previous ends

        UIView.animate(withDuration: duration2, animations: { 

            // Your changes to the UI

            }, completion: { (success) in

                  // This executes when animation is completed

            })

})

Also check other frameworks that could help you, there are a few good ones. I tried Cheetah which supports chaining animations and works really well.

Just ask if you have any questions.