echarts给图例添加点击事件，但是不触发图例关闭

    // 图例点击事件
    onLengenClick() {
    
    
      let totalChart = echarts.init(document.getElementById(this.piedata.id));
      totalChart.on('legendselectchanged', (params) => {
    
    
        console.log(params)
        // 不让图例关闭
        this.cancleLengend(params.selected)
      })
    },
	
    // 取消点击图例后关闭图例
    cancleLengend(selected) {
    
    
      let legend = []
      for (const name in selected) {
    
    
        if (selected.hasOwnProperty(name)) {
    
    
          legend.push({
    
     name: name });
        }
      }  // 关键
      let totalChart = echarts.init(document.getElementById(this.piedata.id));
      totalChart.dispatchAction({
    
    
        type: 'legendSelect',
        batch: legend
      });
    }