如何在Swift中移动对象的位置？

Question

I have an object I'm trying to animate to roll across the screen. I don't know how to change the position of the object and make it spin more than it is already. This is what I have so far:

@IBOutlet weak var quarterImage: UIImageView!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    UIView.animateWithDuration(8.0, animations: {
        let angle = CGFloat(-4000)
        let rotate = CGAffineTransformMakeRotation(angle)
        self.quarterImage.transform = CGAffineTransformMakeRotation(angle)
    })

}

Any help would be great. Thanks!

Answer 1

I am using some bouncing animation of a smiley face image which jumps repeatedly. Here is the code so that you can have idea about changing position. For rotation I guess you need to play around with different PI values of angle to get smooth rotation.

Swift 2

UIView.animateWithDuration(0.6, delay: 0.3, options: [UIViewAnimationOptions.Autoreverse, UIViewAnimationOptions.Repeat, UIViewAnimationOptions.CurveEaseOut], animations:
    {
        self.m_smileyImgView?.transform.ty -= 30;

    },completion: nil);

Swift 3,4,5

UIView.animate(withDuration: 0.6, delay: 0.3, options: [UIView.AnimationOptions.autoreverse, UIView.AnimationOptions.repeat, UIView.AnimationOptions.curveEaseOut], animations:
    {
        self.m_smileyImgView?.transform.ty -= 30;

},completion: nil);

Answer 2

CGAffineTransformMakeRotation can be a little tricky

First of all, it expects degrees in radians

Second of all, values over 2PI doesn't matter (0 = 2PI = 6PI = 10000PI)

Here is an example function for rotating an image 360 degrees

func rotateImage(times times:Int) {
    if times == 0 { return }
    UIView.setAnimationCurve(.Linear)
    UIView.animateKeyframesWithDuration(1, delay: 0, options: .CalculationModeLinear, animations: {
        UIView.addKeyframeWithRelativeStartTime(0, relativeDuration: 1/3, animations: {
            self.imageView.transform = CGAffineTransformMakeRotation(CGFloat(M_PI * 2/3))
        })
        UIView.addKeyframeWithRelativeStartTime(1/3, relativeDuration: 1/3, animations: {
            self.imageView.transform = CGAffineTransformMakeRotation(CGFloat(M_PI * 4/3))
        })
        UIView.addKeyframeWithRelativeStartTime(2/3, relativeDuration: 1/3, animations: {
            self.imageView.transform = CGAffineTransformMakeRotation(CGFloat(M_PI * 2))
        })
    }) { (_) in
        self.rotateImage(times: times - 1)
    }
}

If you want to move the object while you rotate, you can change its position by adding this keyframe

UIView.addKeyframeWithRelativeStartTime(0, relativeDuration: 1.0, animations: { 
                self.imageView.center.x += 50
            })