图随着屏幕大小完成调整

 mounted() {
    window.addEventListener('resize', this.windowResizeHandler, false)
  },
  beforeDestroy() {
    window.removeEventListener('resize', this.windowResizeHandler, false)
  },
  methods: {
    /* 监听窗口变化，重新渲染echatrs图表 */
    windowResizeHandler() {
      if (this.myChart) {
        this.myChart.resize()
      }
    }
}