             if value < 0 {
                 value = 0
             }
+            if (valueChangeBlock != nil) {
+                valueChangeBlock!(value)
+            }
             chunk.center.y = calcYByValue()
         } else if (tapPoint.y >= chunk.center.y + chunkHeight/6) {
             print("+")
             value += 1
             if value > maxValue {
                 value = maxValue
+            }
+            if (valueChangeBlock != nil) {
+                valueChangeBlock!(value)
             }
             chunk.center.y = calcYByValue()
         }

    var selectedColor:UIColor = UIColor.black
    var unselectColor:UIColor = UIColor.red
    var direction:ArrowDirection = .ArrowDirectionHorizontal
    
    private var chunkCircleSize:CGFloat = 0
    

            
            // 根据chunk的y值，计算value
            value = calcValueByY()
            if (valueChangeBlock != nil) {
                valueChangeBlock!(value)
            }
            print("value:\(value)")
            
            setNeedsDisplay()
