如何在屏幕上设置动画时使UIImageView可以进行播放

Question

I have a for in loop that generates dot images which move across the screen. I have no idea where or how to implement a tap gesture recognizer that would be applied to all of the dots that are being generated and be able to make them dissapear when they get tapped as they are moving/animating. Please help me out! Thank you!

@IBAction func animateButton(sender: AnyObject) {

    self.view.userInteractionEnabled = true

    // Declare delay counter
    var delayCounter:Int = 100000
    var durationCounter:Double = 0

    // loop for 1000 times
    for loopNumber in 0...1000 {


        // set up some constants for the animations
        let dotDuration:Double = 4 - durationCounter
        let redDelay = NSTimeInterval(arc4random_uniform(100000) + delayCounter) / 25000
        let blueDelay = NSTimeInterval(arc4random_uniform(100000) + delayCounter) / 25000
        let yellowDelay = NSTimeInterval(arc4random_uniform(100000) + delayCounter) / 25000
        let greenDelay = NSTimeInterval(arc4random_uniform(100000) + delayCounter) / 25000

        let options = UIViewAnimationOptions.AllowUserInteraction

        //set up some constants for the dots
        let redSize:CGFloat = 54
        let redYPosition : CGFloat = CGFloat( arc4random_uniform(275)) + 54

        let blueSize:CGFloat = 54
        let blueYPosition : CGFloat = CGFloat( arc4random_uniform(275)) + 54

        let yellowSize:CGFloat = 54
        let yellowYPosition : CGFloat = CGFloat( arc4random_uniform(275)) + 54

        let greenSize:CGFloat = 54
        let greenYPosition : CGFloat = CGFloat( arc4random_uniform(275)) + 54

        // create the dots and add them to the view
        let redDot = UIImageView()
        redDot.image = UIImage(named: "Red Dot")
        redDot.frame = CGRectMake(0-redSize, redYPosition, redSize, redSize)
        self.view.addSubview(redDot)

        let blueDot = UIImageView()
        blueDot.image = UIImage(named: "Blue Dot")
        blueDot.frame = CGRectMake(0-blueSize, blueYPosition, blueSize, blueSize)
        self.view.addSubview(blueDot)

        let yellowDot = UIImageView()
        yellowDot.image = UIImage(named: "Yellow Dot")
        yellowDot.frame = CGRectMake(0-yellowSize, yellowYPosition, yellowSize, yellowSize)
        self.view.addSubview(yellowDot)

        let greenDot = UIImageView()
        greenDot.image = UIImage(named: "Green Dot")
        greenDot.frame = CGRectMake(0-greenSize, greenYPosition, greenSize, greenSize)
        self.view.addSubview(greenDot)



        // define the animations
        UIView.animateWithDuration(dotDuration , delay: redDelay, options: options, animations: {
            redDot.frame = CGRectMake(675, redYPosition, redSize, redSize)
            }, completion: { animationFinished in redDot.removeFromSuperview() })

        UIView.animateWithDuration(dotDuration , delay: blueDelay, options: options, animations: {
            blueDot.frame = CGRectMake(675, blueYPosition, blueSize, blueSize)
            }, completion: { animationFinished in blueDot.removeFromSuperview() })

        UIView.animateWithDuration(dotDuration , delay: yellowDelay, options: options, animations: {
            yellowDot.frame = CGRectMake(675, yellowYPosition, yellowSize, yellowSize)
            }, completion: { animationFinished in yellowDot.removeFromSuperview() })

        UIView.animateWithDuration(dotDuration , delay: greenDelay, options: options, animations: {
            greenDot.frame = CGRectMake(675, greenYPosition, greenSize, greenSize)
            }, completion: { animationFinished in greenDot.removeFromSuperview() })

        // FAILED ATTEMPT
        var tapDot:UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "dotTapped")

        // FAILED ATTEMPT
        redDot.addGestureRecognizer(tapDot)

        // FAILED ATTEMPT
        func dotTapped (recognizer: UITapGestureRecognizer) {

            redDot.alpha = 0

        }







        durationCounter+=0.05
        delayCounter+=50000
    }


}

Answer 1

1. Your dotTapped method should be outside your animateButton method.
2. Make sure userInteractionEnabled is true for the UIImageView s.