<template>
 <div id="myChart"></div>
</template>

<script>
import echarts from 'echarts'
export default {
 name: 'DynamicLineChart',
 data () {
  return {
  	// 實(shí)時(shí)數(shù)據(jù)數(shù)組
   date: [],
   yieldRate: [],
   yieldIndex: [],
   // 折線圖echarts初始化選項(xiàng)
   echartsOption: {
    legend: {
     data: ['實(shí)際收益率', '大盤(pán)收益率'],
    },
    xAxis: {
     name: '時(shí)間',
     nameTextStyle: {
      fontWeight: 600,
      fontSize: 18
     },
     type: 'category',
     boundaryGap: false,
     data: this.date,	// 綁定實(shí)時(shí)數(shù)據(jù)數(shù)組
    },
    yAxis: {
     name: '實(shí)際收益率',
     nameTextStyle: {
      fontWeight: 600,
      fontSize: 18
     },
     type: 'value',
     scale: true,
     boundaryGap: ['15%', '15%'],
     axisLabel: {
      interval: 'auto',
      formatter: '{value} %'
     }
    },
    tooltip: {
     trigger: 'axis',
    },
    series: [
     {
      name:'實(shí)際收益率',
      type:'line',
      smooth: true,
      data: this.yieldRate,	// 綁定實(shí)時(shí)數(shù)據(jù)數(shù)組
     },
     {
      name:'大盤(pán)收益率',
      type:'line',
      smooth: true,
      data: this.yieldIndex,	// 綁定實(shí)時(shí)數(shù)據(jù)數(shù)組
     }
    ]
   }
  }
 },
 mounted () {
  this.myChart = echarts.init(document.getElementById('myChart'), 'light');	// 初始化echarts, theme為light
  this.myChart.setOption(this.echartsOption);	// echarts設(shè)置初始化選項(xiàng)
  setInterval(this.addData, 3000);	// 每三秒更新實(shí)時(shí)數(shù)據(jù)到折線圖
 },
 methods: {
 	// 獲取當(dāng)前時(shí)間
  getTime : function() {	
   var ts = arguments[0] || 0;
   var t, h, i, s;
   t = ts ? new Date(ts * 1000) : new Date();
   h = t.getHours();
   i = t.getMinutes();
   s = t.getSeconds();
   // 定義時(shí)間格式
   return (h < 10 ? '0' + h : h) + ':' + (i < 10 ? '0' + i : i) + ':' + (s < 10 ? '0' + s : s);
  },
  // 添加實(shí)時(shí)數(shù)據(jù)
  addData : function() {
  	// 從接口獲取數(shù)據(jù)并添加到數(shù)組
   this.$axios.get('url').then((res) => {
    this.yieldRate.push((res.data.actualProfitRate * 100).toFixed(3));
    this.yieldIndex.push((res.data.benchmarkProfitRate * 100).toFixed(3));
    this.date.push(this.getTime(Math.round(new Date().getTime() / 1000)));
    // 重新將數(shù)組賦值給echarts選項(xiàng)
    this.echartsOption.xAxis.data = this.date;
    this.echartsOption.series[0].data = this.yieldRate;
    this.echartsOption.series[1].data = this.yieldIndex;
    this.myChart.setOption(this.echartsOption);
   });
  }
 }
}
</script>

<style>
// 設(shè)定寬高，不然超出windows會(huì)顯示不出來(lái)
#myChart{
 width: 100%;
 height: 500px;
 margin: 0 auto;
}
</style>