iOS-如何设置子类MKAnnotationView大小的动画？

在我的应用程序中，我使用子类MKAnnotationView在地图视图上绘制我自己的“注释”。这很好用

我希望在MapViewController中调用函数“didSelectAnnotationView”时，它将使用SpringNess将注释设置为更大尺寸的动画。在我的例子中，基本大小是CGSize（26，26），较大的大小是CGSize（78，78）

我已经经历了一个地狱般的时间，刚刚到达我的代码所在的位置，至少可以说我已经筋疲力尽了。所以，就目前的情况而言，我甚至没有实现任何动画，我只是想让这该死的东西正确地增长到更大的尺寸。当调用“didSelect”函数时，我调用“myPinView.animateSize（shouldGrow:，fromDrawRect:）”函数重新绘制所有内容，它确实绘制了一个较大的管脚，但它将较小的管脚保留在所有内容下面

任何帮助都将不胜感激

class myPinView: MKAnnotationView {

  var outlineColor: UIColor = UIColor.orangeColor()
  var textSize: CGFloat = CGFloat(9.0)
  var lastTextString: String = ""
  var textLabel: UILabel = UILabel()
  var textString: String = "RG" {
    didSet {
      lastTextString = oldValue
    }
  }

  private var diameter: CGFloat = 0
  private var arcWidth: CGFloat = 0
  private var arcCenter: CGPoint = CGPointZero
  private var startAngle: CGFloat = 3 * pi / 4
  private var endAngle: CGFloat = pi / 4

  required init(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
  }

  override init(frame: CGRect) {
    super.init(frame: frame)
  }

  override init(annotation: MKAnnotation!, reuseIdentifier: String!) {
    super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
  }

override func drawRect(rect: CGRect) {
  super.drawRect(rect)

  drawPin(false, fromDrawRect: true)
}

func animateSize(shouldGrow: Bool, text: String) {

  if shouldGrow {
    textSize = 18.0
    textString = text
  } else {
    textSize = 9.0
    textString = lastTextString
  }

  drawPin(shouldGrow, fromDrawRect: false)

}

func drawPin(shouldGrow: Bool, fromDrawRect: Bool) {

  var b = bounds
  var boundsForDrawing: CGRect

  if shouldGrow {
    boundsForDrawing = CGRect(x: b.origin.x, y: b.origin.y, width:   b.size.width + 52, height: b.size.height + 52)
  } else {
    boundsForDrawing = CGRect(x: b.origin.x, y: b.origin.y, width: 26, height: 26)
  }

  diameter = min(boundsForDrawing.width, boundsForDrawing.height)
  arcWidth = diameter * CGFloat(0.7)
  arcCenter = CGPoint(x: boundsForDrawing.width/2, y: boundsForDrawing.height/2 - (diameter/2 * CGFloat(0.25)))

  var startXoffset = arcCenter.x - (sin(startAngle) * arcWidth/2)
  var startYoffset = arcCenter.y - (cos(startAngle) * arcWidth/2)

  var path = UIBezierPath(
    arcCenter: arcCenter,
    radius: arcWidth/2,
    startAngle: startAngle,
    endAngle: endAngle,
    clockwise: true)

  path.addQuadCurveToPoint(CGPointMake(arcCenter.x, boundsForDrawing.height/2 + diameter/2),
                                    controlPoint: CGPointMake(arcCenter.x, arcCenter.y + (arcWidth * CGFloat(0.7))))
  path.addQuadCurveToPoint(CGPointMake(startXoffset, startYoffset),
                                    controlPoint: CGPointMake(arcCenter.x, arcCenter.y + (arcWidth * CGFloat(0.7))))

  if fromDrawRect {
    layer.shadowColor = UIColor.blackColor().CGColor
    layer.shadowOpacity = 0.5
    layer.shadowOffset = CGSizeMake(0, 5.0)
    layer.anchorPoint = CGPoint(x: 0.5, y: 1.0)
  }

  var innerPath = UIBezierPath(
    arcCenter: arcCenter,
    radius: (arcWidth/2 * CGFloat(0.8)),
    startAngle: 0,
    endAngle: 2 * pi,
    clockwise: true)

  innerPath.lineWidth = CGFloat(1.0)

  var maskOuterLayer = CAShapeLayer()
  maskOuterLayer.path = path.CGPath
  maskOuterLayer.fillColor = outlineColor.CGColor


  var maskInnerLayer = CAShapeLayer()
  maskInnerLayer.path = innerPath.CGPath
  maskInnerLayer.fillColor = UIColor.clearColor().CGColor
  maskInnerLayer.strokeColor = UIColor.blackColor().CGColor

  textLabel.font = UIFont(name: "MarkerFelt-Thin", size: textSize)

  var textPointSize = textLabel.font.pointSize

  var lblStartPoint = CGPointMake(arcCenter.x - (sin(startAngle) * (arcWidth/2 * CGFloat(0.8))),
                                arcCenter.y - (cos(startAngle) * (arcWidth/2 * CGFloat(0.8))))
  var lblSize = CGSizeMake((sin(startAngle) * (arcWidth * CGFloat(0.8))),
                          (cos(startAngle) * (arcWidth * CGFloat(0.8))))

  textLabel.frame = CGRect(origin: lblStartPoint, size: lblSize)
  textLabel.center = arcCenter

  textLabel.text = textString
  textLabel.textColor = UIColor.blackColor()
  textLabel.backgroundColor = UIColor.clearColor()
  textLabel.adjustsFontSizeToFitWidth = true
  textLabel.textAlignment = NSTextAlignment.Center


  maskInnerLayer.addSublayer(textLabel.layer)
  maskOuterLayer.addSublayer(maskInnerLayer)

  if layer.sublayers?.count > 0 {
    layer.replaceSublayer(layer.sublayers[0] as! CAShapeLayer, with: maskOuterLayer)
  } else {
    layer.addSublayer(maskOuterLayer)
  }


  if shouldGrow {
    bounds.size = CGSize(width: 78, height: 78)
  } else {
    if !fromDrawRect {
      bounds.size = CGSize(width: 26, height: 26)
    }
  }
}

}