【原】echarts折线图 tooltip可以显示多条数据，移动到小圆点只显示一条数据

效果图：

解决方案：

通过切换 option.tooltip.trigger

需要有  小圆点

如果 不显示 小圆点，加两行代码：

symbol: 'circle',
symbolSize: 0,

代码如下：

import * as echarts from 'echarts';

var chartDom = document.getElementById('main');
var myChart = echarts.init(chartDom);
var option;

const colors = ['#5470C6', '#EE6666'];
option = {
  color: colors,
  tooltip: {
    trigger: 'axis',
    axisPointer: {
      type: 'line'
    }
  },
  legend: {},
  grid: {
    top: 70,
    bottom: 50
  },
  xAxis: [
    {
      type: 'category',
      axisTick: {
        alignWithLabel: true
      },
      axisLine: {
        onZero: false,
        lineStyle: {
          color: colors[1]
        }
      },
      axisPointer: {
        label: {
          formatter: function (params) {
            return (
              'Precipitation  ' +
              params.value +
              (params.seriesData.length ? '：' + params.seriesData[0].data : '')
            );
          }
        }
      },
      // prettier-ignore
      data: ['2016-1', '2016-2', '2016-3', '2016-4', '2016-5', '2016-6', '2016-7', '2016-8', '2016-9', '2016-10', '2016-11', '2016-12']
    },
    {
      type: 'category',
      axisTick: {
        alignWithLabel: true
      },
      axisLine: {
        onZero: false,
        lineStyle: {
          color: colors[0]
        }
      },
      axisPointer: {
        label: {
          formatter: function (params) {
            return (
              'Precipitation  ' +
              params.value +
              (params.seriesData.length ? '：' + params.seriesData[0].data : '')
            );
          }
        }
      },
      // prettier-ignore
      data: ['2015-1', '2015-2', '2015-3', '2015-4', '2015-5', '2015-6', '2015-7', '2015-8', '2015-9', '2015-10', '2015-11', '2015-12']
    }
  ],
  yAxis: [
    {
      type: 'value'
    }
  ],
  series: [
    {
      name: 'Precipitation(2015)',
      type: 'line',
      xAxisIndex: 1,
      smooth: true,
      // symbol: 'circle',
      // symbolSize: 0,
      emphasis: {
        focus: 'series'
      },
      data: [
        2.6, 5.9, 9.0, 26.4, 28.7, 70.7, 175.6, 182.2, 48.7, 18.8, 6.0, 2.3
      ]
    },
    {
      name: 'Precipitation(2016)',
      type: 'line',
      smooth: true,
      // symbol: 'circle',
      // symbolSize: 0,
      emphasis: {
        focus: 'series'
      },
      data: [
        3.9, 5.9, 11.1, 18.7, 48.3, 69.2, 231.6, 46.6, 55.4, 18.4, 10.3, 0.7
      ]
    }
  ]
};

myChart.on('mouseover', function (params) {
  option.tooltip.trigger = 'item';
  myChart.setOption(option);
});
myChart.on('mouseout', function (params) {
  option.tooltip.trigger = 'axis';
  myChart.setOption(option);
});

option && myChart.setOption(option);