[ECharts] There is a chart instance already initialized on the dom.问题原因

在使用vue绘图的时候，我设置间隔时间进行绘制，控制台一直警告 [ECharts] There is a chart instance already initialized on the dom.
查看代码是因为获取了两次dom进行了初始化

 mounted() {
 
    this.mychart = echarts.init(this.$refs.charts);//此处和下边的initChart方法里重复了



    //实时获取，离开销毁
    let currentTimer = setInterval(() => {
      console.log(this.maxList)
      this.getByIdMax();
    }, 1000);
    this.$once("hook:beforeDestroy", () => {
      clearInterval(currentTimer);
      currentTimer = null;
      console.log("高温预警卡片销毁了");
    });
  },
  methods: {
    //图表初始化
    initChart() {
      //初始化echarts实例(与上方重复获取dom导致出错，删掉即可)
      let lineCharts = echarts.init(this.$refs.charts);