效果展示

这是直接将保存的图片显示在网页下方了
在这里插入图片描述

上代码

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <title>ECharts</title>
    <!-- 引入刚刚下载的 ECharts 文件 -->
    <script src="https://cdn.jsdelivr.net/npm/echarts@5.4.2/dist/echarts.min.js"></script>
	<script type="text/javascript">
		
	</script>
  </head>
  <body>
    <!-- 为 ECharts 准备一个定义了宽高的 DOM -->
    <div id="main" style="width: 900px;height:600px;"></div>
    <script type="text/javascript">

      // 基于准备好的dom，初始化echarts实例
      var myChart = echarts.init(document.getElementById('main'));

      // 指定图表的配置项和数据
      let base = +new Date(1968, 9, 3);
let oneDay = 24 * 3600 * 1000;
let date = [];
let data = [Math.random() * 300];
for (let i = 1; i < 20000; i++) {
  var now = new Date((base += oneDay));
  date.push([now.getFullYear(), now.getMonth() + 1, now.getDate()].join('/'));
  data.push(Math.round((Math.random() - 0.5) * 20 + data[i - 1]));
}
option = {
  tooltip: {
    trigger: 'axis',
    position: function (pt) {
      return [pt[0], '10%'];
    }
  },
  title: {
    left: 'center',
    text: 'Large Area Chart'
  },
  toolbox: {
    feature: {
      dataZoom: {
        yAxisIndex: 'none'
      },
      restore: {},
      saveAsImage: {}
    }
  },
  xAxis: {
    type: 'category',
    boundaryGap: false,
    data: date
  },
  yAxis: {
    type: 'value',
    boundaryGap: [0, '100%']
  },
  dataZoom: [
    {
      type: 'inside',
      start: 0,
      end: 20
    },
    {
      start: 0,
      end: 20
    }
  ],
  series: [
    {
      name: 'Fake Data',
      type: 'line',
      symbol: 'none',
      sampling: 'lttb',
      itemStyle: {
        color: 'rgb(255, 70, 131)'
      },
      areaStyle: {
        color: new echarts.graphic.LinearGradient(0, 0, 0, 1, [
          {
            offset: 0,
            color: 'rgb(255, 158, 68)'
          },
          {
            offset: 1,
            color: 'rgb(255, 70, 131)'
          }
        ])
      },
      data: data
    }
  ]
};

      // 使用刚指定的配置项和数据显示图表。
      myChart.setOption(option);
	  
	  function exportPng(){
			console.log(option.dataZoom);
			
			var div = document.getElementById("imgList");//获取div元素
			var i = 0
			
			var timer = setInterval(function(){
				i++
				
				let dom = document.getElementById('main');
				console.log(dom);
				let canvas = dom.getElementsByTagName('canvas')[0];
				console.log(canvas);
				let myBase64 = canvas.toDataURL('png');
				console.log(myBase64);
				//alert("123");
				
				var im = document.createElement("img");//创建图片
				im.src = myBase64;
				//图片设置成和div一样大小
				im.style.width = 900;
				im.style.height = 600 ;
				div.appendChild(im);	//图片挂载到div上
				
				// 销毁echarts 重新加载
				myChart.dispose();
				option.dataZoom[0].start = i*20
				option.dataZoom[0].end = (i+1)*20
				option.dataZoom[1].start = i*20
				option.dataZoom[1].end = (i+1)*20
				console.log(option.dataZoom);
				
				myChart = echarts.init(document.getElementById('main'));
				myChart.setOption(option);
				
				if(i >= 5){
					//关闭定时器
					clearInterval(timer);
					myChart.dispose();
					option.dataZoom[0].start = 0
					option.dataZoom[0].end = 20
					option.dataZoom[1].start = 0
					option.dataZoom[1].end = 20
					myChart = echarts.init(document.getElementById('main'));
					myChart.setOption(option);
				}
			},2000);

		}
	  
    </script>
	<button onclick="exportPng()">按钮</button>
	<div id = "imgList"></div>
	
  </body>
</html>