我做了一个动画，但是我想把它放在UIImageView中，以便我可以移动它，清除它或重新启动它。
这是我的代码：
@IBOutlet var circle: UIImageView!
// I want to make this inside the circle UIImageView or something like that.
let ovalStartAngle = CGFloat(90.01 * M_PI/180)
let ovalEndAngle = CGFloat(90 * M_PI/180)
let ovalRect = CGRectMake(97.5, 230, 125, 125)
let ovalPath = UIBezierPath()
ovalPath.addArcWithCenter(CGPointMake(CGRectGetMidX(ovalRect), CGRectGetMidY(ovalRect)),
radius: CGRectGetWidth(ovalRect) / 2,
startAngle: ovalStartAngle,
endAngle: ovalEndAngle, clockwise: true)
let progressLine = CAShapeLayer()
progressLine.path = ovalPath.CGPath
progressLine.strokeColor = UIColor.blueColor().CGColor
progressLine.fillColor = UIColor.clearColor().CGColor
progressLine.lineWidth = 10.0
progressLine.lineCap = kCALineCapRound
self.view.layer.addSublayer(progressLine)
let animateStrokeEnd = CABasicAnimation(keyPath: "strokeEnd")
animateStrokeEnd.duration = 10.0
animateStrokeEnd.fromValue = 0.0
animateStrokeEnd.toValue = 1.0
progressLine.addAnimation(animateStrokeEnd, forKey: "animate stroke end animation")