vue监听dom大小改变案例

var elementResizeDetectorMaker = require("element-resize-detector")
erd.listenTo(document.getElementById("swiper"), function(element) {
 var width = element.offsetWidth;
 var height = element.offsetHeight;
 console.log("Size: " + width + "x" + height);
});
//别为我为什么vue用getid。。我懒得改了。用ref获取dom也可以

  this.observer = new ResizeObserver(entries => {
   entries.forEach(() => {
    swiper.updata()
   })
  })
  let content = document.getElementById('swiper')
  this.observer.observe(content)

phontoImage(){   //渲染饼图调用的方法
       var echarts = require('echarts');
       var elementResizeDetectorMaker = require("element-resize-detector");//引入监听dom变化的组件
       var erd = elementResizeDetectorMaker();
       var worldMapContainer = document.getElementById('main4'); //获取 图标容器dom元素
        var that = this;
     //用于使chart自适应高度和宽度,通过窗体高宽计算容器高宽
     var resizeWorldMapContainer = function () {
       worldMapContainer.style.width = worldMapContainer.scrollWidth+'px';
       worldMapContainer.style.height = worldMapContainer.clientHeight+'px';
     };

     // 基于准备好的dom，初始化echarts实例
     var myChart = echarts.init(worldMapContainer);

        //var myChart = echarts.init(document.getElementById('main1'));
        myChart.on('click',function(params){

            that.open(params);

        });

        myChart.setOption({
          title:[
           {
             text: this.data4.name, //环形饼图中间部分的名称
             //subtext:rentalVal,
             textStyle:{  //中间部分字体样式
               fontSize:14,
               color:"black" 
             },
             subtextStyle: { // 中间下边一行字体样式
               fontSize:14,
               color: 'black'
             },
             textAlign:"center",
             x: '43%',   //字体在饼图中的位置
             y: '44%',
           }],
           tooltip : {
             trigger: 'item',
             formatter: "{a} <br/>{b} : {c} ({d}%)"
           },
           legend: {
             type: 'scroll',
             orient: 'vertical',
             right: 10,
             top: 20,
             bottom: 20,
             data: this.data4.names, 
           },
           series : [
             {
               name: this.data4.name,
               type: 'pie',
               radius : ['40%', '60%'], //设置一个区间 就是环形饼状图
               center: ['45%', '50%'],
               data:this.data4.values,
               itemStyle: {
                 emphasis: {
                   shadowBlur: 10,
                   shadowOffsetX: 0,
                   shadowColor: 'rgba(0, 0, 0, 0.5)'
                 },
                 normal:{
                   color:function(params) {
                   //自定义颜色
                   var colorList =['#7c277d','#7460ee', '#FC3468', '#1e88e5', '#ffb22b', '#fc4b6c', '#708069', '#26c6da','#fcc525', '#8d6658'];
                     return colorList[params.dataIndex]
                    }
                 }
               }
             }
           ]
        });
        erd.listenTo(worldMapContainer, function (element) { //执行监听 
          that.$nextTick(function () {
            myChart.resize(); //变化重新渲染饼图

   })
  })
      },