echart縮放時獲取x軸區域的座標

var myChart=eChart.init(document.getElementById('chart'));//給echart要放置的id初始化

option={

   toolbox:{

       dataZoom{}//打開縮放圖標 

  },
  xAxis:{
       type : 'category',
       data:["17-11-06","17-11-07","17-11-08","17-11-09","17-11-10","17-11-11"]//橫座標值
  },
  yAxis:{
       type : 'value'
  },
    series : [
        {
            name:'郵件營銷',
            type:'line',
            areaStyle: {normal: {}},
            data:[120, 132, 101, 134, 90, 230, 210]//縱座標值
        }
    ]

}

myChart.setOption(option);//生成echart圖

chart.on('dataZoom',function(params){//選取的x軸值
   var startX=params.batch[0].startValue;
   var endX=params.batch[0].endValue;
   var  startTime=myChart.xAxis.data[startX];
   var endTime=myChart.xAxis.data[endX];
   console.log(startTime);//區間開始值："17-11-06"
   console.log(endTime);//區間結束值："17-11-08"
}