How to add a completion to an animation?

Question

Hey I want to create a set game app, and now I want my cards(UIViews) move to a newPosition. after the animation ended I want this view to remove from super view

   func btnUp(card: CardSubview, frame: CGRect) {

        let newPosition = CGRect(x: (self.superview?.frame.minX)!, y: (self.superview?.frame.maxY)!, width: card.bounds.width, height: card.bounds.height)
        //UIView.animate(withDuration: 3.0, animations: {card.frame = newPosition})
        UIView.animate(withDuration: 3.0, animations: {card.frame = newPosition}, completion: {if card.frame == newPosition {card.removeFromSuperview()}})

    }

this is working but If I want to add a completion I get this error:

Cannot convert value of type '() -> ()' to expected argument type '((Bool) -> Void)?'**

so what am I doin wrong ?

Possible duplicate of [Blocks on Swift (animateWithDuration:animations:completion:)](https://stackoverflow.com/questions/24071334/blocks-on-swift-animatewithdurationanimationscompletion) — vibhanshu, May 28 '18 at 10:15

Harshal Valanda · Answer 1 · 2018-05-28T10:20:40.083

Try this:

You need to set completion block variable

func btnUp(card: CardSubview, frame: CGRect) {

    let newPosition = CGRect(x: (self.superview?.frame.minX)!, y: (self.superview?.frame.maxY)!, width: card.bounds.width, height: card.bounds.height)
    //UIView.animate(withDuration: 3.0, animations: {card.frame = newPosition})
    UIView.animate(withDuration: 3.0, animations: {
        card.frame = newPosition
        }, completion: { finish in
             if card.frame == newPosition {card.removeFromSuperview()

        }})
}

Vivek Kumar · Answer 2 · 2018-06-05T06:58:03.570

0

UIView.animate(withDuration: 0.25, animations: {
   view.transform = CGAffineTransform(translationX: view.frame.maxX, y: 0)
},completion:{(completed:Bool) in
   if(completed){view.removeFromSuperview()}
})

edited Jun 05 '18 at 06:58

answered May 28 '18 at 10:15

Vivek Kumar

405
5
15

score 0 · Accepted Answer · edited Jun 20 '20 at 09:12

Apple documentation says:

completion

A block object to be executed when the animation sequence ends. This block has no return value and takes a single Boolean argument that indicates whether or not the animations actually finished before the completion handler was called.

So you need to give that boolean argument to completion handler:

UIView.animate(withDuration: 3.0, animations: {card.frame = newPosition}, completion: { finish in
    if card.frame == newPosition {
         card.removeFromSuperview()
    }
})

How to add a completion to an animation?

3 Answers3