QT调用Echart实现数据可视化
由于后续项目可能会需要对数据进行可视化，提前熟悉。
首先到官网下载Echart相关js文件，会跳转到github，下载其中的echarts.js即可：
https://github.com/apache/echarts/tree/5.3.3/dist然后点击示例下载示例文件：
https://echarts.apache.org/examples/zh/index.html
两个文件都下载好后，可以将其放入到项目文件中：
由于UI中没有QWebEngineView类，所以创建一个Widget类控件后将其提升为QWebEngineView类：
然后在Widget的构造函数中加载HTML文件：
得到结果：
此处数据是在js文件中写死的，要能动态显示需要将js文件中相关代码抽离出来封装成函数：
封装成函数后需要主动调用该函数执行一下:
然后重新定义一个带参数的函数init2(str)，在数据部分直接用data: str["data1"]来表示：
<!--
此示例下载自 https://echarts.apache.org/examples/zh/editor.html?c=area-stack
-->
<!DOCTYPE html>
<html lang="zh-CN" style="height: 100%">
<head>
<meta charset="utf-8">
</head>
<body style="height: 100%; margin: 0">
<div id="container" style="height: 100%"></div>
<script type="text/javascript" src="https://fastly.jsdelivr.net/npm/echarts@5.3.3/dist/echarts.min.js"></script>
<!-- Uncomment this line if you want to dataTool extension
<script type="text/javascript" src="https://fastly.jsdelivr.net/npm/echarts@5.3.3/dist/extension/dataTool.min.js"></script>
-->
<!-- Uncomment this line if you want to use gl extension
<script type="text/javascript" src="https://fastly.jsdelivr.net/npm/echarts-gl@2/dist/echarts-gl.min.js"></script>
-->
<!-- Uncomment this line if you want to echarts-stat extension
<script type="text/javascript" src="https://fastly.jsdelivr.net/npm/echarts-stat@latest/dist/ecStat.min.js"></script>
-->
<!-- Uncomment this line if you want to use map
<script type="text/javascript" src="https://fastly.jsdelivr.net/npm/echarts@4.9.0/map/js/china.js"></script>
<script type="text/javascript" src="https://fastly.jsdelivr.net/npm/echarts@4.9.0/map/js/world.js"></script>
-->
<!-- Uncomment these two lines if you want to use bmap extension
<script type="text/javascript" src="https://api.map.baidu.com/api?v=3.0&ak=YOUR_API_KEY"></script>
<script type="text/javascript" src="https://fastly.jsdelivr.net/npm/echarts@5.3.3/dist/extension/bmap.min.js"></script>
-->
<script type="text/javascript">
var dom = document.getElementById('container');
var myChart = echarts.init(dom, null, {
renderer: 'canvas',
useDirtyRect: false
});
var app = {};
function init(){
var option;
option = {
title: {
text: 'Stacked Area Chart'
},
tooltip: {
trigger: 'axis',
axisPointer: {
type: 'cross',
label: {
backgroundColor: '#6a7985'
}
}
},
legend: {
data: ['Email', 'Union Ads', 'Video Ads', 'Direct', 'Search Engine']
},
toolbox: {
feature: {
saveAsImage: {}
}
},
grid: {
left: '3%',
right: '4%',
bottom: '3%',
containLabel: true
},
xAxis: [
{
type: 'category',
boundaryGap: false,
data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
}
],
yAxis: [
{
type: 'value'
}
],
series: [
{
name: 'Email',
type: 'line',
stack: 'Total',
areaStyle: {},
emphasis: {
focus: 'series'
},
data: [0, 0, 0, 0, 0, 0, 0]
},
{
name: 'Union Ads',
type: 'line',
stack: 'Total',
areaStyle: {},
emphasis: {
focus: 'series'
},
data: [0, 0, 0, 0, 0, 0, 0]
},
{
name: 'Video Ads',
type: 'line',
stack: 'Total',
areaStyle: {},
emphasis: {
focus: 'series'
},
data: [0, 0, 0, 0, 0, 0, 0]
},
{
name: 'Direct',
type: 'line',
stack: 'Total',
areaStyle: {},
emphasis: {
focus: 'series'
},
data: [0, 0, 0, 0, 0, 0, 0]
},
{
name: 'Search Engine',
type: 'line',
stack: 'Total',
label: {
show: true,
position: 'top'
},
areaStyle: {},
emphasis: {
focus: 'series'
},
data: [0, 0, 0, 0, 0, 0, 0]
}
]
};
if (option && typeof option === 'object') {
myChart.setOption(option);
}
}
function init2(str){
var option;
option = {
title: {
text: 'Stacked Area Chart'
},
tooltip: {
trigger: 'axis',
axisPointer: {
type: 'cross',
label: {
backgroundColor: '#6a7985'
}
}
},
legend: {
data: ['Email', 'Union Ads', 'Video Ads', 'Direct', 'Search Engine']
},
toolbox: {
feature: {
saveAsImage: {}
}
},
grid: {
left: '3%',
right: '4%',
bottom: '3%',
containLabel: true
},
xAxis: [
{
type: 'category',
boundaryGap: false,
data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
}
],
yAxis: [
{
type: 'value'
}
],
series: [
{
name: 'Email',
type: 'line',
stack: 'Total',
areaStyle: {},
emphasis: {
focus: 'series'
},
data: str["data1"]
},
{
name: 'Union Ads',
type: 'line',
stack: 'Total',
areaStyle: {},
emphasis: {
focus: 'series'
},
data: str["data2"]
},
{
name: 'Video Ads',
type: 'line',
stack: 'Total',
areaStyle: {},
emphasis: {
focus: 'series'
},
data: str["data3"]
},
{
name: 'Direct',
type: 'line',
stack: 'Total',
areaStyle: {},
emphasis: {
focus: 'series'
},
data: str["data4"]
},
{
name: 'Search Engine',
type: 'line',
stack: 'Total',
label: {
show: true,
position: 'top'
},
areaStyle: {},
emphasis: {
focus: 'series'
},
data: str["data5"]
}
]
};
if (option && typeof option === 'object') {
myChart.setOption(option);
}
}
init();
window.addEventListener('resize', myChart.resize);
</script>
</body>
</html>在工程中添加代码：
由于初始化已经将数据全部置为0，现象为：
点击测试后，会调用带字符串的函数，也就会调用到Json中的数据：
当然目前也还是写死的，后续只需要动态更新json中的数据，增加定时器更新，此处的可视化界面也就可以动态变化。
开发时碰到一个问题，就是QT调用Echart会很卡顿，这个现象在Debug时会很明显，但是在Release时是可以正常显示了。
