         cacheImage = nil
         self.drawingPath.removeAllPoints()
         self .setNeedsDisplay()
+        indicatorLabel.hidden = false
     }
     
     func saveAction(){

    //Keep track the four points of bezierPath segment
    private var points = [CGPoint](count: 4, repeatedValue: CGPointZero)
    private var currentTrackIndex = 0
    private lazy var clearButton : UIButton = {
        let button:UIButton = UIButton()
        button.setTitle("重签", forState:.Normal)

        saveButton.backgroundColor = UIColor.lightGrayColor()
        saveButton.addTarget(self, action: "saveAction", forControlEvents: .TouchUpInside)
        return saveButton
    }()
    private lazy var indicatorLabel : UILabel = {
       let label = UILabel()
        label.text = "请在此签名"
        label.textColor = UIColor.init(red: 200/255, green: 200/255, blue: 200/255, alpha: 1)
        return label
    }()
    
    // MARK: Public Var
