// 基于准备好的dom，初始化echarts实例
let myChart = this.$echarts.init(document.getElementById('myChart'))
//根据窗口的大小变动图表 --- 重点
window.onresize = function(){
  myChart.resize();
  //myChart1.resize();  //若有多个图表变动，可多写
 
}

mounted() {
  
 const that = this
   window.onresize = () => {// 根据窗口大小调整曲线大小
   let myChart = this.$echarts.init(document.getElementById('myChart'));
    myChart.resize();
   }
 },

import echarts from 'echarts';
import Vue from 'vue';
import elementResizeDetectorMaker from "element-resize-detector"

export var version = '0.0.1';
var compatible = (/^2\./).test(Vue.version);
if (!compatible) {
  Vue.util.warn('vue echarts resize directive ' + version + ' only supports Vue 2.x, and does not support Vue ' + Vue.version);
}
let HANDLER = "_vue_echarts_resize_handler"

function bind(el) {
  unbind(el);
  el[HANDLER] = function () {
    let chart = echarts.getInstanceByDom(el);
    if (!chart) {
      return;
    }
    chart.resize();
  }
  //监听window窗体变化，更新echarts大小
  //window.addEventListener("resize", el[HANDLER])
  //监听绑定的div大小变化，更新echarts大小
  elementResizeDetectorMaker().listenTo(el,el[HANDLER])
  
}
function unbind(el) {
  //window.removeEventListener("resize", el[HANDLER]);
  elementResizeDetectorMaker().removeListener(el,el[HANDLER])
  delete el[HANDLER];
}
var directive = {
  bind: bind,
  unbind: unbind
};
Vue.directive("on-echart-resize", directive)

<template>
 <div id="leftEchartsLine" ref="leftEchartsLine" v-on-echart-resize></div>
</template>

 mounted() {
  let erd = elementResizeDetectorMaker();
  let that = this;
  erd.listenTo(document.getElementById("leftEchartsLine"), (element) => {
   let width = element.offsetWidth;
   let height = element.offsetHeight;
   that.$nextTick(() => {
    //使echarts尺寸重置
    that.echarts.init(document.getElementById("leftEchartsLine")).resize();
   });
  });
 },