【无标题】Echarts饼图默认选中一个

 		  let myChart = this.chart;
          let index = 0; //默认选中第一个
          myChart.dispatchAction({
            type: "highlight",
            seriesIndex: 0,
            dataIndex: 0,
          });
          //下面的事件一定要写，如果不写会出现重影的情况
          myChart.on("mouseover", function (e) {
            if (e.dataIndex != index) {
              myChart.dispatchAction({
                type: "downplay",
                seriesIndex: 0,
                dataIndex: index,
              });
            }
          });
          myChart.on("mouseout", function (e) {
            index = e.dataIndex;
            myChart.dispatchAction({
              type: "highlight",
              seriesIndex: 0,
              dataIndex: e.dataIndex,
            });
          });