echarts 实时动态折线图（vue）

效果展示：

<div class="nowEcharts" id="nowEcharts"></div>



<style >
.nowEcharts {
  width: 100%;
  height: 300px;
  margin-bottom: 0.3rem;
}
</style>

1.先在data中定义option

nowOptions: {
        visualMap: [
          {
            show: false,
            type: 'continuous',
            seriesIndex: 0,
            min: 0,
            max: 400,
          },
        ],
        title: {
          left: 'left',
          text: '电量消耗实时统计',
        },
        tooltip: {
          trigger: 'axis',
          formatter: function(params) {
            params = params[0]
            var date = new Date(params.name)
            return (
              date.getDate() +
              '/' +
              (date.getMonth() + 1) +
              '/' +
              date.getFullYear() +
              ' : ' +
              params.value[1]
            )
          },
          axisPointer: {
            animation: false,
          },
        },
        grid: {
          top: '15%',
          bottom: '10%',
        },
        xAxis: {
          type: 'time',
          splitLine: {
            show: false,
          },
          triggerEvent: true,
        },
        yAxis: {
          type: 'value',
          boundaryGap: [0, '100%'],
          max: 100,
          splitLine: {
            show: false,
          },
        },
        series: [
          {
            type: 'line',
            showSymbol: false,
            hoverAnimation: false,
            data: [],
          },
        ],
      },

2.生成折线图

（1）初始化数据

nowChart() {
      let that = this
      var data = []
      var now = +new Date()
      var value = Math.random() * 1000
      for (var i = 0; i < 60; i++) {
        now = new Date(+now + this.oneDay)
        data.push(this.randomData(now, value))
      }
      // 基于准备好的dom，初始化echarts实例
      var myChart = echarts.init(document.getElementById('nowEcharts'))

      // 绘制图表
      var temp = 59
      let options = Object.assign(that.nowOptions, {})
      options.series.forEach((item) => {
        item.data = data
        item.markPoint = {
          data: [
            [
              {
                symbol: 'none',
                x: '95%',
              },
              {
                symbol: 'circle',
                name: '实时数据',
                value: data[temp].value[1],
                xAxis: data[temp].value[0],
              },
            ],
          ],
        }
      })
      myChart.setOption(options)
      // 1秒定时器
      setInterval(() => {
        for (var i = 0; i < 1; i++) {
          data.shift()
          now = new Date(+now + this.oneDay)
          data.push(this.randomData(now, value))
        }
        myChart.setOption(options)
      }, 1000)
    },

（2）生成随机数

 randomData(now, value) {
      value = Math.random() * 100
      var valueName =
        now.getFullYear() +
        '/' +
        (now.getMonth() + 1) +
        '/' +
        now.getDate() +
        ' ' +
        (now.getHours() >= 10 ? now.getHours() : '0' + now.getHours()) +
        ':' +
        (now.getMinutes() >= 10 ? now.getMinutes() : '0' + now.getMinutes()) +
        ':' +
        (now.getSeconds() >= 10 ? now.getSeconds() : '0' + now.getSeconds())
      return {
        name: now.toString(),
        value: [valueName, Math.round(value)],
      }
    },