<transition 
 		@before-enter="beforeEnter"
 		@enter="enter"
 		@after-enter="afterEnter">
 		<div class="ball" v-if="Ballflag" ref="ball"></div> //Ballflag默认指定为false不显示
 	</transition>

.ball{
		width: 15px;
		height: 15px;
		border-radius: 50%;
		background-color: red;
		position: absolute;
		top: 413px;
		left: 80px;
		z-index: 99;
}

.ball{
		width: 15px;
		height: 15px;
		border-radius: 50%;
		background-color: red;
		position: absolute;
		top: 413px;
		left: 80px;
		z-index: 99;
}

.ball{
		width: 15px;
		height: 15px;
		border-radius: 50%;
		background-color: red;
		position: fixed;
		z-index: 99;
		top: 413px;
		left: 80px;

	}

beforeEnter(el){
			
			var boxPosition = this.$refs.boxPosition.getBoundingClientRect();
			// console.log(boxPosition)
			// 获取目标的起始位置 
			var dist = boxPosition.y -413;
			el.style.transform = "translate(0,"+dist+"px)";
		},
		enter(el,done){
			el.offsetWidth;
			
			var boxPosition = this.$refs.boxPosition.getBoundingClientRect();
			var badgePosition = document.getElementById("badge").getBoundingClientRect();

			//目标的起始位置
			var dist = boxPosition.y -413; 
			
			// 这里因为是使用boxPosition的位置不是小球的位置所以-10调整一下误差
			var xDist = badgePosition.left - boxPosition.left -10; 

			//这里要加上起始的定位
			var yDist = badgePosition.top - boxPosition.top + dist;
			
			el.style.transform = "translate("+xDist+"px, "+yDist+"px)";
			el.style.transition = "all 1s ease";
			done();
		},
		afterEnter(el){
			this.Ballflag = !this.Ballflag;
		},