echart事件

reference： https://www.w3cschool.cn/echarts_tutorial/echarts_tutorial-7o3u28yh.html

var mychart = echarts.init(document.getElementById('abc'));
var option ={....}//忽略了具体参数
mychart.on('click',function(params){console.log(params);console.log(params.dataIndex);......
});