vue監聽移動端左滑、右滑、上滑、下滑、長按事件

1. 定義一個監聽touch指令，主要根據計算開始到結束滑動的位置計算X、Y軸相應的距離再計算角度來判斷滑動的方向

   directives:{
   	//滑動指令
   	touch:{
       bind: function (el, binding, vnode) {
         var touchType = binding.arg; //傳入的模式 press swipeRight swipeLeft swipeTop swipeDowm Tap
         var timeOutEvent = 0;
         var direction = '';
         //滑動處理
         var startX, startY;
   
         //返回角度
         function GetSlideAngle(dx, dy) {
           return Math.atan2(dy, dx) * 180 / Math.PI;
         }
   
         //根據起點和終點返回方向 1：向上，2：向下，3：向左，4：向右,0：未滑動
         function GetSlideDirection(startX, startY, endX, endY) {
           var dy = startY - endY;
           var dx = endX - startX;
           var result = 0;
   
           //若是滑動距離過短
           if (Math.abs(dx) < 2 && Math.abs(dy) < 2) {
             return result;
           }
   
           var angle = GetSlideAngle(dx, dy);
           if (angle >= -45 && angle < 45) {
             result = 'swiperight';
           } else if (angle >= 45 && angle < 135) {
             result = 'swipeup';
           } else if (angle >= -135 && angle < -45) {
             result = 'swipedown';
           }
           else if ((angle >= 135 && angle <= 180) || (angle >= -180 && angle < -135)) {
             result = 'swipeleft';
           }
           return result;
         }
   
         el.addEventListener('touchstart', function (ev) {
           startX = ev.touches[0].pageX;
           startY = ev.touches[0].pageY;
   
           //判斷長按
           timeOutEvent = setTimeout(() =>{
             timeOutEvent = 0 ;
             if(touchType === 'press'){
                 binding.value()
             }
           } , 500);
   
         }, false);
   
         el.addEventListener('touchmove' , function (ev) {
           clearTimeout(timeOutEvent)
           timeOutEvent = 0;
         });
   
         el.addEventListener('touchend', function (ev) {
           var endX, endY;
           endX = ev.changedTouches[0].pageX;
           endY = ev.changedTouches[0].pageY;
           direction = GetSlideDirection(startX, startY, endX, endY);
   
           clearTimeout(timeOutEvent)
   
           switch (direction) {
             case 0:
               break;
             case 'swipeup':
               if(touchType === 'swipeup'){
                   binding.value()
               }
               break;
             case 'swipedown':
               if(touchType === 'swipedown'){
                   binding.value()
               }
               break;
             case 'swipeleft':
               if(touchType === 'swipeleft'){
                   binding.value()
               }
               break;
             case 'swiperight':
               if(touchType === 'swiperight'){
                   binding.value()
               }
               break;
             default:
           }
     		}, false);
       }
   	}
   }

    

2. 在標籤綁定指令和事件，並在methods定義事件。

   <div v-touch:swipeleft="leftSlide" v-touch:swiperight="rightSlide">
    
   </div>

   leftSlide() {
   	console.log('左滑')
   },
   rightSlide() {
   	console.log('右滑')
   }