Echarts绘制柱状图，顶点连接

核心代码是使用 markLine属性，需要一个一个顶点去绘制，暂时没找到更好的方式，效果如图：

代码：

option = {
  tooltip: {
    trigger: 'axis',
    axisPointer: {
      type: 'shadow'
    }
  },
  legend: {},
  grid: {
    left: '3%',
    right: '4%',
    bottom: '3%',
    containLabel: true
  },
  xAxis: [
    {
      type: 'category',
      data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
    }
  ],
  yAxis: [
    {
      type: 'value'
    }
  ],
  series: [
    {
      name: 'Direct',
      type: 'bar',
      emphasis: {
        focus: 'series'
      },
      data: [320, 332, 301, 334, 390, 330, 320]
    },
    {
      name: 'Email',
      type: 'bar',
      stack: 'Ad',
      emphasis: {
        focus: 'series'
      },
      data: [120, 132, 101, 134, 90, 230, 210]
    },
    {
      name: 'Union Ads',
      type: 'bar',
      stack: 'Ad',
      emphasis: {
        focus: 'series'
      },
      data: [220, 182, 191, 234, 290, 330, 310]
    },
    {
      name: 'Video Ads',
      type: 'bar',
      stack: 'Ad',
      emphasis: {
        focus: 'series'
      },
      data: [150, 232, 201, 154, 190, 330, 410]
    },
    {
      name: 'Search Engine',
      type: 'bar',
      data: [862, 1018, 964, 1026, 1679, 1600, 1570],
      emphasis: {
        focus: 'series'
      },
      markLine: {
        lineStyle: {
          type: 'dashed'
        },
        data:[
          [{coord:[0,862]},{coord:[1,1018],symbol:'circle'}],
          [{coord:[1,1018]},{coord:[2,964],symbol:'circle'}],
          [{coord:[2,964]},{coord:[3,1026],symbol:'circle'}],
          [{coord:[3,1026]},{coord:[4,1679],symbol:'circle'}]
        ]
      }
    },
    {
      name: 'Baidu',
      type: 'bar',
      barWidth: 5,
      stack: 'Search Engine',
      emphasis: {
        focus: 'series'
      },
      data: [620, 732, 701, 734, 1090, 1130, 1120]
    },
    {
      name: 'Google',
      type: 'bar',
      stack: 'Search Engine',
      emphasis: {
        focus: 'series'
      },
      data: [120, 132, 101, 134, 290, 230, 220]
    },
    {
      name: 'Bing',
      type: 'bar',
      stack: 'Search Engine',
      emphasis: {
        focus: 'series'
      },
      data: [60, 72, 71, 74, 190, 130, 110]
    },
    {
      name: 'Others',
      type: 'bar',
      stack: 'Search Engine',
      emphasis: {
        focus: 'series'
      },
      data: [62, 82, 91, 84, 109, 110, 120]
    }
  ]
};