11.x轴超长隐藏，鼠标移上去显示全部

//步骤一：x轴添加triggerEvent:true 和 xAxis隐藏过长的文字
xAxis: {
    type: "category",
    triggerEvent: true, //添加triggerEvent:true
    axisLabel: {
        show: true,
        formatter: function(value) { //隐藏过长的文字
            var res = value;
            if (res.length > 5) {
                res = res.substring(0, 4) + "..";
            }
            return res;
        }
    }
},
//步骤二：调用extension()
async mounted() {
    const chart = echarts.init(this.$refs.chart1);
    chart.setOption(this.chartOption);
    await this.fetchData();
},
methods: {
    extension(mychart) {
      //判断是否创建过div框,如果创建过就不再创建了
      var id = document.getElementById("extension");
      if (!id) {
        var div = `<div id = 'extension' sytle="display:none"></div>`;
        $("html").append(div);
      }
      mychart.on("mouseover", function(params) {
        if (params.componentType == "xAxis") {
          $("#extension")
            .css({
              position: "absolute",
              color: "black",
              "font-family": "Arial",
              "font-size": "14px",
              padding: "5px",
              display: "inline",
              backgroundColor: "rgba(8,49,107,0.5)"
            })
            .text(params.value);
          $("html").mousemove(function(event) {
            var xx = event.pageX - 30;
            var yy = event.pageY + 10;
            $("#extension")
              .css("top", yy)
              .css("left", xx);
          });
        }
      });
      mychart.on("mouseout", function(params) {
        if (params.componentType == "xAxis") {
          $("#extension").css("display", "none");
        }
      });
    },
    async fetchData() {
      let xData = ["工业亩均产值1工业亩均产值1","工业亩均产值2","工业亩均产值3","工业亩均产值4"];
      let series1 = [3000, 2000, 1500, 2500];
      let series2 = [4000, 3800, 4200, 3800];
      const chart = echarts.init(this.$refs.chart1);
      chart.setOption({
        xAxis: {
          data: xData
        },
        series: [{ data: series1 }, { data: series2 }]
      });
      this.extension(chart); //调用extension()
    },
}