Qt+ECharts开发笔记（四）：ECharts的饼图介绍、基础使用和Qt封装百分比图Demo

前言

前一篇介绍了横向柱图图。本篇将介绍基础饼图使用，并将其封装一层Qt。
本篇的demo使用隐藏js代码的方式，实现了一个饼图的基本交互方式，并预留了Qt模块对外的基础接口。

Demo演示

请添加图片描述

ECharts代码效果调试

使用ECharts的在线调试器，先调试出大致预期的效果。

option = {
  legend: {
    top: '90%',
    show: false
  },
  series: [
    {
      selectedMode: 'single',    // 选择模式
      selectedOffset: 10,       // 选取后偏移，需要先设置选择模式才生效
      type: 'pie',               // 图例类型
      radius: ['60%', '90%'],     // 同心圆双边界区域
      itemStyle: {	             // 数据项样式
        borderRadius: 0,       // 边界圆角
        borderColor: '#FF0000',  // 边界颜色
        borderWidth: 0        // 边界宽度
      },
      label: {
        show: true,
        fontSize: '32',
        fontWeight: 'bold',
        formatter: '{b}\n\n{d}%',
        position: 'center'
      },
      emphasis: {
        // 高亮状态的扇区和标签样式
        label: {
          show: false,
          fontSize: '32',
          fontWeight: 'bold'
        }
      },
      labelLine: {
        show: true
      },
      data: [
        {
          value: 5.6,
          name: '开机率',
          itemStyle: {
            color: 'rgb(41, 235, 255)',
            shadowBlur: 10,      // 外阴影
            shadowOffsetX: 0,    // 外阴影x轴偏移
            shadowOffsetY: 0,    // 外阴影y轴偏移
            shadowColor: 'rgb(41, 235, 255)' // 外阴影颜色
          }
        },
        {
          value: 5.2,
          name: '',
          itemStyle: {
            color: 'rgba(45,62,113)',
            shadowBlur: 10,
            shadowOffsetX: 0,
            shadowOffsetY: 0,
            shadowColor: 'rgba(45,62,113)'
          }
        }
      ]
    }
  ]
};

Qt封装动态ECharts

步骤一：静态html

此系列的标准html文件。

html>
<html>
  <head>
    <meta charset="utf-8" />
    <title>EChartstitle>
    <script src="./echarts.js">script>
  head>
  <body>
    <style>
        #main,
        html,
        body{
            width: 100%;
            height: 100%;
            overflow: hidden;
        }
        #main {
            width: 95%;
            height: 95%;
        }
    style>
    <div id="main">div>
    <script type="text/javascript">
        var myChart = echarts.init(document.getElementById('main'));
        window.onresize = function() {
            myChart.resize();
        };
    script>
  body>
html>

步骤二：初始化

这里是我们不让鼠标点击，只用于观看，鼠标相关的效果EChart4和EChart5也有一些不同，ECharts4交互的坑，查看本文章最后“入坑“章节。

void PieEChartWidget::initControl()
{
    _pLabelCenterUp = new QLabel(this);
    _pLabelCenterUp->raise();
    _pLabelCenterUp->setAlignment(Qt::AlignBottom | Qt::AlignHCenter);
    _pLabelCenterUp->setText(QSTRING("开机率"));
    _pLabelCenterUp->setStyleSheet("font-size: 36px;"
                                   "font-weight: bold;"
                                   "align: top ;"
                                   "color: rgb(41, 235, 255);"
                                   "padding: 0 30 10 0;");
    _pLabelCenterDown = new QLabel(this);
    _pLabelCenterDown->raise();
    _pLabelCenterDown->setAlignment(Qt::AlignTop | Qt::AlignHCenter);
    _pLabelCenterDown->setText(QSTRING("%1%").arg(0));
    _pLabelCenterDown->setStyleSheet("font-size: 64px;"
                                     "font-weight: bold;"
                                     "align: center;"
                                     "color: rgb(41, 235, 255);"
                                     "padding: 0 30 0 0;");


    _pWebEngineView = new QWebEngineView(this);
    _pWebEnginePage = new QWebEnginePage(this);
    _pWebChannel = new QWebChannel(this);
    QString filePath;
#if 0
    // 使用绝对路径
    filePath = QString("%1/%2").arg(_htmlDir).arg(_indexFileName);
#else
    // 使用资源路径
    filePath = "qrc:/pieEChartWidget/html/eChartWidget.html";
#endif
    LOG << "file exist:" << QFile::exists(filePath) << filePath;
#if 0
    // 打印html文件内容
    QFile file(_indexFilePath);
    file.open(QIODevice::ReadOnly);
    LOG << QString(file.readAll());
    file.close();
#endif
    connect(_pWebEnginePage, SIGNAL(loadFinished(bool)), this, SLOT(slot_loadFinished(bool)));
    _pWebEnginePage->load(QUrl(filePath));
    _pWebEnginePage->setWebChannel(_pWebChannel);
    _pWebEngineView->setPage(_pWebEnginePage);

    // 背景透明
//    _pWebEngineView->setStyleSheet("background-color: transparent");
    _pWebEnginePage->setBackgroundColor(Qt::transparent);

    // 鼠标穿透
    _pWebEngineView->setAttribute(Qt::WA_TransparentForMouseEvents, true);
}

步骤三：将需要的接口预留

设置百分数，文本上要注意位置偏移，手动进行校准：

void PieEChartWidget::setPercent(double percent)
{
    if(percent < 0 || percent > 100)
    {
        return;
    }
    LOG << percent;
    if(percent == 100)
    {
        _pLabelCenterDown->setText(QSTRING("100%"));
    }else{
        if(_percent < 10)
        {
            _pLabelCenterDown->setText(QSTRING("%1%").arg(percent, 0, 'g', 2));
        }else{
            _pLabelCenterDown->setText(QSTRING(" %1%").arg(percent, 0, 'g', 2));
        }
    }

    QString jsStr = QSTRING(
                            "option.series[0].data[0].value = %1;"
                            "option.series[0].data[1].value = %2;"
                            "myChart.setOption(option, true);")
                            .arg(percent)
                            .arg(100 - percent);
    LOG << jsStr;

    _percent = percent;

    runJsScript(jsStr);
}

步骤四：动态操作

重置

void PieEChartWidget::on_pushButton_reset_clicked()
{
    initJs();
}

刷新

void PieEChartWidget::on_pushButton_flush_clicked()
{
    QString jsStr =
            "var empty = {};"
            "myChart.setOption(empty, true);"
            "myChart.setOption(option, true);";
    runJsScript(jsStr);
}

随机生成（使用Qt代码）

void PieEChartWidget::on_pushButton_createRandom_clicked()
{
    float value = qrand() % 10001 / 100;
    setPercent(value);
}

清除数据

void PieEChartWidget::on_pushButton_clear_clicked()
{
    setPercent(0.0f);
}

指定值

void PieEChartWidget::on_doubleSpinBox_valueChanged(double arg1)
{
    setPercent(ui->doubleSpinBox->value());
}

Demo源码

PieEChartWidget.h

#ifndef PIEECHARTWIDGET_H
#define PIEECHARTWIDGET_H

#include 
#include 
#include 
#include 
#include 

namespace Ui {
class PieEChartWidget;
}

class PieEChartWidget : public QWidget
{
    Q_OBJECT

public:
    explicit PieEChartWidget(QWidget *parent = 0);
    ~PieEChartWidget();

public:
    void setPercent(double percent);

protected:
    void initControl();

protected slots:
    void slot_loadFinished(bool result);

protected:
    void initJs();

protected:
    void runJsScript(QString str);

protected:
    void resizeEvent(QResizeEvent *event);

private slots:
    void on_pushButton_clear_clicked();
    void on_pushButton_flush_clicked();
    void on_pushButton_createRandom_clicked();
    void on_pushButton_reset_clicked();
    void on_doubleSpinBox_valueChanged(double arg1);

private:
    Ui::PieEChartWidget *ui;

private:
    QWebEngineView *_pWebEngineView;            // 浏览器窗口
    QWebEnginePage *_pWebEnginePage;            // 浏览器页面
    QWebChannel *_pWebChannel;                  // 浏览器js交互

    QString _htmlDir;                           // html文件夹路径
    QString _indexFileName;                     // html文件

    QLabel *_pLabelCenterUp;                    // 显示文字的控件
    QLabel *_pLabelCenterDown;                  // 显示百分比的控件

    QString _initJsStr;                         // 初始化的js字符串
    QString _initValueJsStr;                    // 设置值的js字符串

private:
    double _percent;                            // 百分比(0~100)

};

#endif // PIEECHARTWIDGET_H

PieEChartWidget.cpp

#include "PieEChartWidget.h"
#include "ui_PieEChartWidget.h"

#include 
#include 
#include 

// QtCreator在msvc下设置编码也或有一些乱码，直接一刀切,避免繁琐的设置
//#define MSVC
#ifdef MSVC
#define QSTRING(s)  QString::fromLocal8Bit(s)
#else
#define QSTRING(s)  QString(s)
#endif

#include 
#include 
//#define LOG qDebug()<<__FILE__<<__LINE__
//#define LOG qDebug()<<__FILE__<<__LINE__<<__FUNCTION__
//#define LOG qDebug()<<__FILE__<<__LINE__<
//#define LOG qDebug()<<__FILE__<<__LINE__<
#define LOG qDebug()<<__FILE__<<__LINE__<"yyyy-MM-dd hh:mm:ss:zzz")

PieEChartWidget::PieEChartWidget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::PieEChartWidget),
    _pWebEngineView(0),
    _pWebEnginePage(0),
    _pWebChannel(0),
    _htmlDir("D:/qtProject/echartsDemo/echartsDemo/modules/PieEChartWidget/html"),    // 使用了绝对路径,引到html文件夹
    _indexFileName("PieEChartWidget.html"),
    _pLabelCenterUp(0),
    _pLabelCenterDown(0)
{
    ui->setupUi(this);

    QString version = "v1.0.0";
    setWindowTitle(QString("基于Qt的EChartb饼状图Demo %1(长沙红胖子Qt").arg(version));

    // 设置无边框，以及背景透明
    // 背景透明，在界面构架时，若为本窗口为其他窗口提升为本窗口时，
    // 则再qss会在主窗口第一级添加frame_all，防止其他窗口提升本窗口而冲掉qss设置
//    setWindowFlag(Qt::FramelessWindowHint);
//    setAttribute(Qt::WA_TranslucentBackground, true);

#if 0
    // 这是方法一：让滚动条不出来(通过大小)，还有一个方法是在html设置body的overflow: hidden
//    resize(600 + 20, 400 + 20);
#endif

    initControl();
}

PieEChartWidget::~PieEChartWidget()
{
    delete ui;
}

void PieEChartWidget::setPercent(double percent)
{
    if(percent < 0 || percent > 100)
    {
        return;
    }
    LOG << percent;
    if(percent == 100)
    {
        _pLabelCenterDown->setText(QSTRING("100%"));
    }else{
        if(_percent < 10)
        {
            _pLabelCenterDown->setText(QSTRING("%1%").arg(percent, 0, 'g', 2));
        }else{
            _pLabelCenterDown->setText(QSTRING(" %1%").arg(percent, 0, 'g', 2));
        }
    }

    QString jsStr = QSTRING(
                            "option.series[0].data[0].value = %1;"
                            "option.series[0].data[1].value = %2;"
                            "myChart.setOption(option, true);")
                            .arg(percent)
                            .arg(100 - percent);
    LOG << jsStr;

    _percent = percent;

    runJsScript(jsStr);
}

void PieEChartWidget::initControl()
{
    _pLabelCenterUp = new QLabel(this);
    _pLabelCenterUp->raise();
    _pLabelCenterUp->setAlignment(Qt::AlignBottom | Qt::AlignHCenter);
    _pLabelCenterUp->setText(QSTRING("开机率"));
    _pLabelCenterUp->setStyleSheet("font-size: 36px;"
                                   "font-weight: bold;"
                                   "align: top ;"
                                   "color: rgb(41, 235, 255);"
                                   "padding: 0 30 10 0;");
    _pLabelCenterDown = new QLabel(this);
    _pLabelCenterDown->raise();
    _pLabelCenterDown->setAlignment(Qt::AlignTop | Qt::AlignHCenter);
    _pLabelCenterDown->setText(QSTRING("%1%").arg(0));
    _pLabelCenterDown->setStyleSheet("font-size: 64px;"
                                     "font-weight: bold;"
                                     "align: center;"
                                     "color: rgb(41, 235, 255);"
                                     "padding: 0 30 0 0;");


    _pWebEngineView = new QWebEngineView(this);
    _pWebEnginePage = new QWebEnginePage(this);
    _pWebChannel = new QWebChannel(this);
    QString filePath;
#if 0
    // 使用绝对路径
    filePath = QString("%1/%2").arg(_htmlDir).arg(_indexFileName);
#else
    // 使用资源路径
    filePath = "qrc:/pieEChartWidget/html/eChartWidget.html";
#endif
    LOG << "file exist:" << QFile::exists(filePath) << filePath;
#if 0
    // 打印html文件内容
    QFile file(_indexFilePath);
    file.open(QIODevice::ReadOnly);
    LOG << QString(file.readAll());
    file.close();
#endif
    connect(_pWebEnginePage, SIGNAL(loadFinished(bool)), this, SLOT(slot_loadFinished(bool)));
    _pWebEnginePage->load(QUrl(filePath));
    _pWebEnginePage->setWebChannel(_pWebChannel);
    _pWebEngineView->setPage(_pWebEnginePage);

    // 背景透明
//    _pWebEngineView->setStyleSheet("background-color: transparent");
    _pWebEnginePage->setBackgroundColor(Qt::transparent);

    // 鼠标穿透
    _pWebEngineView->setAttribute(Qt::WA_TransparentForMouseEvents, true);
}

void PieEChartWidget::slot_loadFinished(bool result)
{
    if(result)
    {
        initJs();
        resizeEvent(0);
    }
}

void PieEChartWidget::initJs()
{
    _initJsStr = QSTRING(
                "var option;"
                "option = {"
                "  legend: {"
                "    top: '90%',"
                "    show: false"
                "  },"
                "  series: ["
                "    {"
                "      selectedMode: 'single',      /* 选择模式 */"
                "      selectedOffset: 0,           /* 选取后偏移，需要先设置选择模式才生效 */"
                "      type: 'pie',                 /* 图例类型 */"
                "      radius: ['60%', '90%'],      /* 同心圆双边界区域 */"
                "      itemStyle: {                 /* 数据项样式 */"
                "        borderRadius: 0,           /* 边界圆角 */"
                "        borderColor: '#FF0000',    /* 边界颜色 */"
                "        borderWidth: 0             /* 边界宽度 */"
                "      },"
                "      avoidLabelOverlap: true,"
                "      label: {"
                "        show: false,"
                "        fontSize: '32',"
                "        fontWeight: 'bold',"
                "        formatter: '{b}\\n\\n{d}%',"
                "        position: 'center'"
                "      },"
                "      emphasis: {                  /* 高亮状态的扇区和标签样式 */"
                "        label: {"
                "          show: false,"
                "          fontSize: '32',"
                "          fontWeight: 'bold'"
                "        }"
                "      },"
                "      labelLine: {"
                "        show: false"
                "      },"
                "      data: ["
                "        {"
                "          value: 0,"
                "          name: '开机率',"
                "          selected: true,"
                "          itemStyle: {"
                "            color: 'rgba(41, 235, 255, 255)',"
                "            shadowColor:'rgba(41, 235, 255, 255)',"
                "            shadowBlur: 10,"
                "            shadowOffsetX: 0,"
                "            shadowOffsetY: 0,"
                "          }"
                "        },"
                "        {"
                "          value: 100,"
                "          name: '11',"
                "          itemStyle: {"
                "            color: 'rgba(45,62,113,255)',"
                "            shadowColor:'rgba(45,62,113,255)',"
                "            shadowBlur: 10,"
                "            shadowOffsetX: 0,"
                "            shadowOffsetY: 0,"
                "          }"
                "        }"
                "      ]"
                "    }"
                "  ]"
                "};"
                "myChart.setOption(option);"
                );
    {
        _initValueJsStr = QSTRING(
                "var option;"
                "option = {"
                "  legend: {"
                "    top: '90%',"
                "    show: false"
                "  },"
                "  series: ["
                "    {"
                "      selectedMode: 'single',      /* 选择模式 */"
                "      selectedOffset: 0,           /* 选取后偏移，需要先设置选择模式才生效 */"
                "      type: 'pie',                 /* 图例类型 */"
                "      radius: ['60%', '90%'],      /* 同心圆双边界区域 */"
                "      itemStyle: {                 /* 数据项样式 */"
                "        borderRadius: 0,           /* 边界圆角 */"
                "        borderColor: '#FF0000',    /* 边界颜色 */"
                "        borderWidth: 0             /* 边界宽度 */"
                "      },"
                "      avoidLabelOverlap: true,"
                "      label: {"
                "        show: false,"
                "        fontSize: '32',"
                "        fontWeight: 'bold',"
                "        formatter: '{b}\\n\\n{d}%',"
                "        position: 'center'"
                "      },"
                "      emphasis: {                  /* 高亮状态的扇区和标签样式 */"
                "        label: {"
                "          show: false,"
                "          fontSize: '32',"
                "          fontWeight: 'bold'"
                "        }"
                "      },"
                "      labelLine: {"
                "        show: false"
                "      },"
                "      data: ["
                "        {"
                "          value: %1,"
                "          name: '开机率',"
                "          selected: true,"
                "          itemStyle: {"
                "            color: 'rgba(41, 235, 255, 255)',"
                "            shadowColor:'rgba(41, 235, 255, 255)',"
                "            shadowBlur: 10,"
                "            shadowOffsetX: 0,"
                "            shadowOffsetY: 0,"
                "          }"
                "        },"
                "        {"
                "          value: %2,"
                "          name: '',"
                "          itemStyle: {"
                "            color: 'rgba(45, 62, 113, 255)',"
                "            shadowColor:'rgba(45,62,113,255)',"
                "            shadowBlur: 10,"
                "            shadowOffsetX: 0,"
                "            shadowOffsetY: 0,"
                "          }"
                "        }"
                "      ]"
                "    }"
                "  ]"
                "};"
                "myChart.setOption(option);"
                );
    }
    setPercent(0);
    runJsScript(_initJsStr);
}

void PieEChartWidget::runJsScript(QString str)
{
    if(_pWebEnginePage)
    {
        _pWebEnginePage->runJavaScript(str);
    }
}

void PieEChartWidget::resizeEvent(QResizeEvent *event)
{
    if(_pWebEngineView)
    {
        _pWebEngineView->setGeometry(ui->label_echarts->geometry());
    }
    if(_pLabelCenterUp)
    {
        QRect echarRect = ui->label_echarts->geometry();
        _pLabelCenterUp->setGeometry(echarRect.x(),
                                     echarRect.y(),
                                     echarRect.width(),
                                     echarRect.height()/2);
    }
    if(_pLabelCenterDown)
    {
        QRect echarRect = ui->label_echarts->geometry();
        _pLabelCenterDown->setGeometry(echarRect.x(),
                                       echarRect.y() + echarRect.height()/2,
                                       echarRect.width(),
                                       echarRect.height()/2);
    }
}

void PieEChartWidget::on_pushButton_clear_clicked()
{
    setPercent(0.0f);
}

void PieEChartWidget::on_pushButton_flush_clicked()
{
    QString jsStr =
            "var empty = {};"
            "myChart.setOption(empty, true);"
            "myChart.setOption(option, true);";
    runJsScript(jsStr);
}

void PieEChartWidget::on_pushButton_createRandom_clicked()
{
    float value = qrand() % 10001 / 100;
    setPercent(value);
}

void PieEChartWidget::on_pushButton_reset_clicked()
{
    initJs();
}

void PieEChartWidget::on_doubleSpinBox_valueChanged(double arg1)
{
    setPercent(ui->doubleSpinBox->value());
}

工程模板v1.3.0

在这里插入图片描述

入坑

入坑一：js出现错误“unexpected token”

问题

在这里插入图片描述

原理

判断传入编码转换或者语法规则有问题
在这里插入图片描述

解决方法

从字符串这种方式，只能使用/**/，如下图：
在这里插入图片描述

入坑二：出现Invalid or unexpected token错误

问题

在这里插入图片描述

原理

在这里插入图片描述
判断输入在定义label格式的时候，输入了特殊字符，导致整条字符串没有达到预期转义

解决方法

发现打印出来是对的也不行，主要是给换行符加上，换行符qt的直接换行展示为\n，到浏览器那边估计是直接换行了，导致不在一行了。
改掉即可，给\n改成\n，建议可打印出来看一看即可。
在这里插入图片描述

入坑三：嵌入Qt中的显示不对

问题

在这里插入图片描述

原理

重新一条一条递增添加js语句找到问题为样式部分的问题。
在这里插入图片描述

解决

rgba改a即可，这是之前测试过rgba，rgba中的a是有效果的。

入坑四：Qt中实际饼图的默认Label显示不对

问题

Label显示不对

在这里插入图片描述

原理

版本相关，但qt无法嵌入echart5无法显示（具体原因查看本系列第一篇）。

其他尝试

最起码笔者使用的这个版本是有问题的。
直接加载js文件，也是如此：
在这里插入图片描述

解决

绕开，用QLabel显示混合显示。

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原文地址：https://www.cnblogs.com/qq21497936/p/16587463.html