// MARK: - Override
 // 当手指接触屏幕时，就会调用touchesBegan:withEvent方法；
 override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
  print("执行touchesBegan")
  selectBtnTagArray.removeAll()
  touchesChange(touches)
 }
 //当手指在屏幕上移动时，调用touchesMoved:withEvent方法；
 override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
  touchesChange(touches)
 }
 //当触摸被取消（比如触摸过程中被来电打断），就会调用touchesCancelled:withEvent方法。
 override func touchesCancelled(touches: Set<UITouch>?, withEvent event: UIEvent?) {
 }
 //当手指离开屏幕时，就会调用touchesEnded:withEvent方法；
 override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
  print("执行touchesEnded")
  var alertTitle = "请设置正确的手势"
  var alertMessage = "手势密码不能少于4个"
  var isSuccess = false
  if selectBtnTagArray.count >= 4 {
   alertTitle = "手势密码设置成功"
   isSuccess = true
   alertMessage = "密码为：\(selectBtnTagArray)"
  }
  gestureLockDelegate!.gestureLockSuccess(isSuccess, title: alertTitle, message: alertMessage)
  gesturePoint = CGPointZero;
  self.setNeedsDisplay()
 }
 // MARK: - PrivateMethod
 private func initButtons() {
  for i in 0...8 {
   //第几行
   let row = i / 3
   let loc = i % 3
   //两个button的间距
   let btnSpace = (screenWidth - 3*btnWH)/4
   let btnX = btnSpace + (btnWH + btnSpace) * CGFloat(loc)
   let btnY = 70 + btnSpace + (btnWH + btnSpace) * CGFloat(row)
   let gestureNodeBtn = UIButton(frame:CGRectMake(btnX, btnY, btnWH, btnWH))
   gestureNodeBtn.tag = i
   gestureNodeBtn.userInteractionEnabled = false //不响应用户的交互。一定要加上这句
   gestureNodeBtn.setImage(UIImage(named: btnImgNormal), forState: .Normal)
   self.addSubview(gestureNodeBtn)
   btnArray.append(gestureNodeBtn)
  }
 }
 private func touchesChange(touches: Set<UITouch>) {
  //获取 触摸对象 ,触摸对象的位置坐标来实现
  gesturePoint = touches.first!.locationInView(self)
  for btn in btnArray {
   //判断 手指的坐标 是否在 button的坐标里
   if !selectBtnTagArray.contains(btn.tag) && CGRectContainsPoint(btn.frame, gesturePoint) {
    //处理跳跃连线
    var lineCenterPoint:CGPoint = CGPoint()
    if selectBtnTagArray.count > 0 {
     lineCenterPoint = centerPoint(btn.frame.origin, endPoint: btnArray[selectBtnTagArray.last!].frame.origin)
    }
    //保存中间跳跃 过的节点
    for btn in btnArray {
     if !selectBtnTagArray.contains(btn.tag) && CGRectContainsPoint(btn.frame, lineCenterPoint) {
      btn.setImage(UIImage(named: btnImgSelected), forState: .Normal)
      selectBtnTagArray.append(btn.tag)
     }
    }
    //保存划过的按钮的tag
    selectBtnTagArray.append(btn.tag)
    btn.setImage(UIImage(named: btnImgSelected), forState: .Normal)
   }
  }
  //setNeedsDisplay会自动调用drawRect方法 进行画线
  self.setNeedsDisplay()
 }
 //计算2个节点中心的坐标
 private func centerPoint(startPoint: CGPoint, endPoint:CGPoint) -> CGPoint {
  let rightPoint = startPoint.x > endPoint.x ? startPoint.x : endPoint.x
  let leftPoint = startPoint.x < endPoint.x ? startPoint.x : endPoint.x
  let topPoint = startPoint.y > endPoint.y ? startPoint.y : endPoint.y
  let bottomPoint = startPoint.y < endPoint.y ? startPoint.y : endPoint.y
  //x坐标： leftPoint +（rightPoint-leftPoint)/2 = (rightPoint+leftPoint)/2
  return CGPointMake((rightPoint + leftPoint)/2 + btnWH/2, (topPoint + bottomPoint)/2 + btnWH/2);
 }
 func recoverNodeStatus() {
  selectBtnTagArray.removeAll()
  for btn in btnArray {
   btn.setImage(UIImage(named: btnImgNormal), forState: .Normal)
  }
  self.setNeedsDisplay()
 }

 override func drawRect(rect: CGRect) {
  print("执行drawRect")
  let context = UIGraphicsGetCurrentContext() //获取画笔上下文
  var i = 0
  for tag in selectBtnTagArray {
   if (0 == i) {
    //开始画线,设置直线的起点坐标
    CGContextMoveToPoint(context, btnArray[tag].center.x, btnArray[tag].center.y)
   } else {
    //画直线,设置直线的终点坐标
    CGContextAddLineToPoint(context, btnArray[tag].center.x,btnArray[tag].center.y)
   }
   i = i+1
  }
  //如果有选中的节点，就取 跟着 手指的滑动 画线
  if (selectBtnTagArray.count > 0) {
   // 移除最后一条多余的线，
   if gesturePoint != CGPointZero {
    CGContextAddLineToPoint(context, gesturePoint.x, gesturePoint.y)
   }
  }
  CGContextSetLineWidth(context, 10)  //设置画笔宽度
  CGContextSetLineJoin(context, .Round) //两个线相交点 平滑处理
  CGContextSetLineCap(context, .Round) //设置线条两端的样式为圆角
  CGContextSetRGBStrokeColor(context, 227/255.0, 54/255.0, 58/255.0, 1)
  CGContextStrokePath(context)   // //对线条进行渲染
 }