echarts
ECharts 是一个使用 JavaScript 实现的开源可视化库，主要用于数据的可视化展示。ECharts 支持丰富的图表类型，如折线图、柱状图、饼图、地图、K线图等，可以满足不同类型数据的展示需求。
文档地址：echarts
本次所绘制三维柱状图主要使用的是示例源代码，在此基础上做了些修改。
引入CDN
使用echarts需要导入echarts和echarts-gl。
免费的CDN服务可访问网址：Staticfile CDN
<!-- 引入 ECharts 文件 -->
<script src="https://cdn.jsdelivr.net/npm/echarts@latest/dist/echarts.min.js"></script>
<script src="https://cdn.staticfile.net/echarts-gl/2.0.8/echarts-gl.js"></script>
HTML结构
设置一个container容器存放三维柱状图，设置一个下载png图片按钮。根据id选择器设置样式。
<!DOCTYPE html>
<html lang="">
<head><meta charset="utf-8"><title>ECharts</title><!-- 引入 ECharts 文件 --><script src="https://cdn.jsdelivr.net/npm/echarts@latest/dist/echarts.min.js"></script><script src="https://cdn.staticfile.net/echarts-gl/2.0.8/echarts-gl.js"></script><style>#container {width: 900px;height: 800px;margin-left: 300px;margin-top: -120px;}#download{margin-left: 300px;}</style>
</head>
<body>
<!-- 准备一个 DOM 容器 -->
<div id="container"></div>
<button id="download">Download as PNG</button>
<script type="text/javascript"...>
</body>
</html>
echarts属性设置
visualMap组件可以根据Z轴值的大小映射出不同的颜色。graphic组件可以添加文字说明。
const dom = document.getElementById('container');const myChart = echarts.init(dom, null, {renderer: 'canvas',useDirtyRect: false});let option;// prettier-ignoreconst hours = ['12a', '1a', '2a', '3a', '4a', '5a', '6a','7a', '8a', '9a', '10a', '11a','12p', '1p', '2p', '3p', '4p', '5p','6p', '7p', '8p', '9p', '10p', '11p'];// prettier-ignoreconst days = ['Saturday', 'Friday', 'Thursday','Wednesday', 'Tuesday', 'Monday', 'Sunday'];// prettier-ignoreconst data = [[0, 0, 5], [0, 1, 1], [0, 2, 0], [0, 3, 0], [0, 4, 0], [0, 5, 0], [0, 6, 0], [0, 7, 0], [0, 8, 0], [0, 9, 0], [0, 10, 0], [0, 11, 2], [0, 12, 4], [0, 13, 1], [0, 14, 1], [0, 15, 3], [0, 16, 4], [0, 17, 6], [0, 18, 4], [0, 19, 4], [0, 20, 3], [0, 21, 3], [0, 22, 2], [0, 23, 5], [1, 0, 7], [1, 1, 0], [1, 2, 0], [1, 3, 0], [1, 4, 0], [1, 5, 0], [1, 6, 0], [1, 7, 0], [1, 8, 0], [1, 9, 0], [1, 10, 5], [1, 11, 2], [1, 12, 2], [1, 13, 6], [1, 14, 9], [1, 15, 11], [1, 16, 6], [1, 17, 7], [1, 18, 8], [1, 19, 12], [1, 20, 5], [1, 21, 5], [1, 22, 7], [1, 23, 2], [2, 0, 1], [2, 1, 1], [2, 2, 0], [2, 3, 0], [2, 4, 0], [2, 5, 0], [2, 6, 0], [2, 7, 0], [2, 8, 0], [2, 9, 0], [2, 10, 3], [2, 11, 2], [2, 12, 1], [2, 13, 9], [2, 14, 8], [2, 15, 10], [2, 16, 6], [2, 17, 5], [2, 18, 5], [2, 19, 5], [2, 20, 7], [2, 21, 4], [2, 22, 2], [2, 23, 4], [3, 0, 7], [3, 1, 3], [3, 2, 0], [3, 3, 0], [3, 4, 0], [3, 5, 0], [3, 6, 0], [3, 7, 0], [3, 8, 1], [3, 9, 0], [3, 10, 5], [3, 11, 4], [3, 12, 7], [3, 13, 14], [3, 14, 13], [3, 15, 12], [3, 16, 9], [3, 17, 5], [3, 18, 5], [3, 19, 10], [3, 20, 6], [3, 21, 4], [3, 22, 4], [3, 23, 1], [4, 0, 1], [4, 1, 3], [4, 2, 0], [4, 3, 0], [4, 4, 0], [4, 5, 1], [4, 6, 0], [4, 7, 0], [4, 8, 0], [4, 9, 2], [4, 10, 4], [4, 11, 4], [4, 12, 2], [4, 13, 4], [4, 14, 4], [4, 15, 14], [4, 16, 12], [4, 17, 1], [4, 18, 8], [4, 19, 5], [4, 20, 3], [4, 21, 7], [4, 22, 3], [4, 23, 0], [5, 0, 2], [5, 1, 1], [5, 2, 0], [5, 3, 3], [5, 4, 0], [5, 5, 0], [5, 6, 0], [5, 7, 0], [5, 8, 2], [5, 9, 0], [5, 10, 4], [5, 11, 1], [5, 12, 5], [5, 13, 10], [5, 14, 5], [5, 15, 7], [5, 16, 11], [5, 17, 6], [5, 18, 0], [5, 19, 5], [5, 20, 3], [5, 21, 4], [5, 22, 2], [5, 23, 0], [6, 0, 1], [6, 1, 0], [6, 2, 0], [6, 3, 0], [6, 4, 0], [6, 5, 0], [6, 6, 0], [6, 7, 0], [6, 8, 0], [6, 9, 0], [6, 10, 1], [6, 11, 0], [6, 12, 2], [6, 13, 1], [6, 14, 3], [6, 15, 4], [6, 16, 0], [6, 17, 0], [6, 18, 0], [6, 19, 0], [6, 20, 1], [6, 21, 2], [6, 22, 2], [6, 23, 6]];option = {tooltip: {},// visualMap组件根据Z轴值的大小映射不同的颜色visualMap: {min: 0,max: 20,text: ['20', '0'],bottom: '10%',inRange: {color: ['#313695','#4575b4','#74add1','#abd9e9','#e0f3f8','#ffffbf','#fee090','#fdae61','#f46d43','#d73027','#a50026']}},// graphic组件添加说明文本graphic: [{type: 'text',left: '5%',bottom: '21%',style: {text: 'value',fill: '#000',font: '14px Microsoft YaHei'}}],xAxis3D: {type: 'category',data: hours,name: 'test1'},yAxis3D: {type: 'category',data: days,name: 'test2',nameGap: 25, // 设置Y轴名称与轴线之间的距离，单位是像素axisLabel: {// 设置标注与轴线之间的间距margin: 5 // 这里的20可以根据需要调整为其他值}},zAxis3D: {type: 'value',name: 'test3'},grid3D: {boxWidth: 200,boxDepth: 80,viewControl: {// projection: 'orthographic'},light: {main: {intensity: 1.2,shadow: true},ambient: {intensity: 0.3}}},series: [{type: 'bar3D',data: data.map(function (item) {return {value: [item[1], item[0], item[2]]};}),shading: 'lambert',label: {fontSize: 16,borderWidth: 1},emphasis: {label: {fontSize: 20,color: '#900'},itemStyle: {color: '#900'}}}]};
if (option && typeof option === 'object') {myChart.setOption(option);}window.addEventListener('resize', myChart.resize);
添加下载事件
通过添加下载事件可以将HTML中的图片转换成png格式。
// 添加下载事件
document.getElementById('download').addEventListener('click', function() {// 使用echarts的getDataURL方法获取图表的Base64编码const url = myChart.getDataURL({type: 'png',pixelRatio: 2, // 设置图像的分辨率backgroundColor: '#fff' // 设置背景色（可选）});// 创建一个下载链接const a = document.createElement('a');a.href = url;a.download = 'chart.png';document.body.appendChild(a);a.click();document.body.removeChild(a);
});
完整代码
<!DOCTYPE html>
<html lang="">
<head><meta charset="utf-8"><title>ECharts</title><!-- 引入 ECharts 文件 --><script src="https://cdn.jsdelivr.net/npm/echarts@latest/dist/echarts.min.js"></script><script src="https://cdn.staticfile.net/echarts-gl/2.0.8/echarts-gl.js"></script><style>#container {width: 900px;height: 800px;margin-left: 300px;margin-top: -120px;}#download{margin-left: 300px;}</style>
</head>
<body>
<!-- 准备一个 DOM 容器 -->
<div id="container"></div>
<button id="download">Download as PNG</button>
<script type="text/javascript">const dom = document.getElementById('container');const myChart = echarts.init(dom, null, {renderer: 'canvas',useDirtyRect: false});let option;// prettier-ignoreconst hours = ['12a', '1a', '2a', '3a', '4a', '5a', '6a','7a', '8a', '9a', '10a', '11a','12p', '1p', '2p', '3p', '4p', '5p','6p', '7p', '8p', '9p', '10p', '11p'];// prettier-ignoreconst days = ['Saturday', 'Friday', 'Thursday','Wednesday', 'Tuesday', 'Monday', 'Sunday'];// prettier-ignoreconst data = [[0, 0, 5], [0, 1, 1], [0, 2, 0], [0, 3, 0], [0, 4, 0], [0, 5, 0], [0, 6, 0], [0, 7, 0], [0, 8, 0], [0, 9, 0], [0, 10, 0], [0, 11, 2], [0, 12, 4], [0, 13, 1], [0, 14, 1], [0, 15, 3], [0, 16, 4], [0, 17, 6], [0, 18, 4], [0, 19, 4], [0, 20, 3], [0, 21, 3], [0, 22, 2], [0, 23, 5], [1, 0, 7], [1, 1, 0], [1, 2, 0], [1, 3, 0], [1, 4, 0], [1, 5, 0], [1, 6, 0], [1, 7, 0], [1, 8, 0], [1, 9, 0], [1, 10, 5], [1, 11, 2], [1, 12, 2], [1, 13, 6], [1, 14, 9], [1, 15, 11], [1, 16, 6], [1, 17, 7], [1, 18, 8], [1, 19, 12], [1, 20, 5], [1, 21, 5], [1, 22, 7], [1, 23, 2], [2, 0, 1], [2, 1, 1], [2, 2, 0], [2, 3, 0], [2, 4, 0], [2, 5, 0], [2, 6, 0], [2, 7, 0], [2, 8, 0], [2, 9, 0], [2, 10, 3], [2, 11, 2], [2, 12, 1], [2, 13, 9], [2, 14, 8], [2, 15, 10], [2, 16, 6], [2, 17, 5], [2, 18, 5], [2, 19, 5], [2, 20, 7], [2, 21, 4], [2, 22, 2], [2, 23, 4], [3, 0, 7], [3, 1, 3], [3, 2, 0], [3, 3, 0], [3, 4, 0], [3, 5, 0], [3, 6, 0], [3, 7, 0], [3, 8, 1], [3, 9, 0], [3, 10, 5], [3, 11, 4], [3, 12, 7], [3, 13, 14], [3, 14, 13], [3, 15, 12], [3, 16, 9], [3, 17, 5], [3, 18, 5], [3, 19, 10], [3, 20, 6], [3, 21, 4], [3, 22, 4], [3, 23, 1], [4, 0, 1], [4, 1, 3], [4, 2, 0], [4, 3, 0], [4, 4, 0], [4, 5, 1], [4, 6, 0], [4, 7, 0], [4, 8, 0], [4, 9, 2], [4, 10, 4], [4, 11, 4], [4, 12, 2], [4, 13, 4], [4, 14, 4], [4, 15, 14], [4, 16, 12], [4, 17, 1], [4, 18, 8], [4, 19, 5], [4, 20, 3], [4, 21, 7], [4, 22, 3], [4, 23, 0], [5, 0, 2], [5, 1, 1], [5, 2, 0], [5, 3, 3], [5, 4, 0], [5, 5, 0], [5, 6, 0], [5, 7, 0], [5, 8, 2], [5, 9, 0], [5, 10, 4], [5, 11, 1], [5, 12, 5], [5, 13, 10], [5, 14, 5], [5, 15, 7], [5, 16, 11], [5, 17, 6], [5, 18, 0], [5, 19, 5], [5, 20, 3], [5, 21, 4], [5, 22, 2], [5, 23, 0], [6, 0, 1], [6, 1, 0], [6, 2, 0], [6, 3, 0], [6, 4, 0], [6, 5, 0], [6, 6, 0], [6, 7, 0], [6, 8, 0], [6, 9, 0], [6, 10, 1], [6, 11, 0], [6, 12, 2], [6, 13, 1], [6, 14, 3], [6, 15, 4], [6, 16, 0], [6, 17, 0], [6, 18, 0], [6, 19, 0], [6, 20, 1], [6, 21, 2], [6, 22, 2], [6, 23, 6]];option = {tooltip: {},// visualMap组件根据Z轴值的大小映射不同的颜色visualMap: {min: 0,max: 20,text: ['20', '0'],bottom: '10%',inRange: {color: ['#313695','#4575b4','#74add1','#abd9e9','#e0f3f8','#ffffbf','#fee090','#fdae61','#f46d43','#d73027','#a50026']}},// graphic组件添加说明文本graphic: [{type: 'text',left: '5%',bottom: '21%',style: {text: 'value',fill: '#000',font: '14px Microsoft YaHei'}}],xAxis3D: {type: 'category',data: hours,name: 'test1'},yAxis3D: {type: 'category',data: days,name: 'test2',nameGap: 25, // 设置Y轴名称与轴线之间的距离，单位是像素axisLabel: {// 设置标注与轴线之间的间距margin: 5 // 这里的20可以根据需要调整为其他值}},zAxis3D: {type: 'value',name: 'test3'},grid3D: {boxWidth: 200,boxDepth: 80,viewControl: {// projection: 'orthographic'},light: {main: {intensity: 1.2,shadow: true},ambient: {intensity: 0.3}}},series: [{type: 'bar3D',data: data.map(function (item) {return {value: [item[1], item[0], item[2]]};}),shading: 'lambert',label: {fontSize: 16,borderWidth: 1},emphasis: {label: {fontSize: 20,color: '#900'},itemStyle: {color: '#900'}}}]};// 添加下载事件document.getElementById('download').addEventListener('click', function() {// 使用echarts的getDataURL方法获取图表的Base64编码const url = myChart.getDataURL({type: 'png',pixelRatio: 2, // 设置图像的分辨率backgroundColor: '#fff' // 设置背景色（可选）});// 创建一个下载链接const a = document.createElement('a');a.href = url;a.download = 'chart.png';document.body.appendChild(a);a.click();document.body.removeChild(a);});if (option && typeof option === 'object') {myChart.setOption(option);}window.addEventListener('resize', myChart.resize);
</script>
</body>
</html>结果展示
点击下载按钮，即可保存为png格式。
 - 显示底部收发，优化串口打开/关闭)
