Echart折线图：当多条折线存在相同name,图例仍全部显示

默认情况

option = {
  title: {
    text: 'Stacked Line'
  },
  tooltip: {
    trigger: 'axis'
  },
  legend: {
    show: true
    // data: ['Email', 'Union Ads', 'Video Ads', 'Direct', 'Search Engine']
  },
  grid: {
    left: '3%',
    right: '4%',
    bottom: '3%',
    containLabel: true
  },
  toolbox: {
    feature: {
      saveAsImage: {}
    }
  },
  xAxis: {
    type: 'category',
    boundaryGap: false,
    data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
  },
  yAxis: {
    type: 'value'
  },
  series: [
    {
      name: 'Email',
      type: 'line',
      stack: 'Total',
      data: [120, 132, 101, 134, 90, 230, 210]
    },
    {
      name: 'Union Ads',
      type: 'line',
      stack: 'Total',
      data: [220, 182, 191, 234, 290, 330, 310]
    },
    {
      name: 'Video Ads',
      type: 'line',
      stack: 'Total',
      data: [150, 232, 201, 154, 190, 330, 410]
    },
    {
      name: 'Direct',
      type: 'line',
      stack: 'Total',
      data: [320, 332, 301, 334, 390, 330, 320]
    },
    {
      name: 'Search Engine',
      type: 'line',
      stack: 'Total',
      data: [820, 932, 901, 934, 1290, 1330, 1320]
    }
  ]
};

当折线存在相同名称时，图例相同的只会显示一个

option = {
  title: {
    text: 'Stacked Line'
  },
  tooltip: {
    trigger: 'axis'
  },
  legend: {
    show: true
    // data: ['Email', 'Union Ads', 'Video Ads', 'Direct', 'Search Engine']
  },
  grid: {
    left: '3%',
    right: '4%',
    bottom: '3%',
    containLabel: true
  },
  toolbox: {
    feature: {
      saveAsImage: {}
    }
  },
  xAxis: {
    type: 'category',
    boundaryGap: false,
    data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
  },
  yAxis: {
    type: 'value'
  },
  series: [
    {
      name: 'Email',
      type: 'line',
      stack: 'Total',
      data: [120, 132, 101, 134, 90, 230, 210]
    },
    {
      name: 'Email',
      type: 'line',
      stack: 'Total',
      data: [220, 182, 191, 234, 290, 330, 310]
    },
    {
      name: 'Video Ads',
      type: 'line',
      stack: 'Total',
      data: [150, 232, 201, 154, 190, 330, 410]
    },
    {
      name: 'Direct',
      type: 'line',
      stack: 'Total',
      data: [320, 332, 301, 334, 390, 330, 320]
    },
    {
      name: 'Search Engine',
      type: 'line',
      stack: 'Total',
      data: [820, 932, 901, 934, 1290, 1330, 1320]
    }
  ]
};

当折线图存在相同名称时，也展示全部图例。

解决逻辑：
series系列中的name设置唯一值；legend通过formatter，利用唯一id获取相应的名称来展示；浮窗通过data中的value数组的设置的name来显示。

主要利用legend的formatter方法

浮窗的内容也需要修改

option = {
  title: {
    text: 'Stacked Line'
  },
  tooltip: {
    trigger: 'axis',
    formatter: (params) => {
      let arr = [
        {
          name: '3333',
          type: 'line',
          text: 'Videot',
          data: [120, 132, 101, 134, 90, 230, 210]
        },
        {
          name: 'Videot',
          type: 'line',
          text: 'Videot',
          data: [220, 182, 191, 234, 290, 330, 310]
        },
        {
          name: 'Videot1',
          type: 'line',
          text: 'Videot',
          data: [150, 232, 201, 154, 190, 330, 410]
        },
        {
          name: 'Search Engine',
          type: 'line',
          text: 'Search Engine',
          data: [320, 332, 301, 334, 390, 330, 320]
        },
        {
          name: 'Search Engine1',
          type: 'line',
          text: 'Search Engine',
          data: [820, 932, 901, 934, 1290, 1330, 1320]
        }
      ];
      let middle = ``;
      for (let i = 0; i < params.length; i++) {
        let name = arr.find((v) => v.name === params[i].seriesName).text;
        middle += `<div>
       <span> ${name}</span>:
       <span>${params[i].value}</span>
        </div>`;
      }
      let content = `
      <div>
    ${middle}
      </div>`;
      return content;
    }
  },
  legend: {
    show: true,
    // data: ['Email', 'Union Ads', 'Video Ads', 'Direct', 'Search Engine'],
    formatter: (name) => {
      let arr = [
        {
          name: '3333',
          type: 'line',
          text: 'Videot',
          data: [120, 132, 101, 134, 90, 230, 210]
        },
        {
          name: 'Videot',
          type: 'line',
          text: 'Videot',
          data: [220, 182, 191, 234, 290, 330, 310]
        },
        {
          name: 'Videot1',
          type: 'line',
          text: 'Videot',
          data: [150, 232, 201, 154, 190, 330, 410]
        },
        {
          name: 'Search Engine',
          type: 'line',
          text: 'Search Engine',
          data: [320, 332, 301, 334, 390, 330, 320]
        },
        {
          name: 'Search Engine1',
          type: 'line',
          text: 'Search Engine',
          data: [820, 932, 901, 934, 1290, 1330, 1320]
        }
      ];
      let showText = arr.find((v) => v.name === name).text;
      return showText;
    }
  },
  grid: {
    left: '3%',
    right: '4%',
    bottom: '3%',
    containLabel: true
  },
  toolbox: {
    feature: {
      saveAsImage: {}
    }
  },
  xAxis: {
    type: 'category',
    boundaryGap: false,
    data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
  },
  yAxis: {
    type: 'value'
  },
  series: [
    {
      name: '3333',
      type: 'line',
      data: [120, 132, 101, 134, 90, 230, 210]
    },
    {
      name: 'Videot',
      type: 'line',
      data: [220, 182, 191, 234, 290, 330, 310]
    },
    {
      name: 'Videot1',
      type: 'line',
      data: [150, 232, 201, 154, 190, 330, 410]
    },
    {
      name: 'Search Engine',
      type: 'line',
      data: [320, 332, 301, 334, 390, 330, 320]
    },
    {
      name: 'Search Engine1',
      type: 'line',
      data: [820, 932, 901, 934, 1290, 1330, 1320]
    }
  ]
};