按钮长按事件

iOS有长按手势UILongPressGestureRecognizer，这个手势需要指定长按的事件，指定时间之后，触发事件

现在需要实现长按的过程中就执行某一个动作，并且中途取消长按事件可以终止动作

需要重写 UIGestureRecognizer的几个方法

1.初始化长按手势,传入长按手势结束之后需要执行的动作

```
override init(target: Any?, action: Selector?) {
    super.init(target: target, action: action)
    myTarget = target as AnyObject!
    myAction = action
}


```

2.重写手势开始的方法，手势一开始，启动定时器，跟随长按按钮开始事件

  override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
      setUp()
  }

  func setUp() {
      
      if progressTimer == nil {
          
          progressTimer = Timer.scheduledTimer(timeInterval: 0.03, target: self, selector: #selector(self.handleTimer(_:)), userInfo: nil, repeats: true)
          
      }
      
      startDate = Date()
  }

3.手势取消的时候，停止定时器，状态置为 possible

```
override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent) {
    if self.progressTimer != nil {
        self.state = .possible
        //取消定时器
        tearDown("Cancel")
    }
}


```

4.手势结束的时候，停止定时器，状态置为 possible

```
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
    if self.progressTimer != nil {
        
        if !isTriggered {
           self.isEnabled = false
            self.isEnabled = true
        }
        
        self.state = .possible

        //取消定时器
        tearDown("Cancel")

    }

}


```