C++ Qt开发：Charts绘制各类图表详解

QChart *chart = new QChart();
chart->setTitle("柱状图统计");
chart->setAnimationOptions(QChart::SeriesAnimations);

// 为graphicsView设置chart
ui->graphicsView->setChart(chart);
ui->graphicsView->setRenderHint(QPainter::Antialiasing);

// 构造柱状图
chart =ui->graphicsView->chart();
chart->removeAllSeries();            // 删除所有序列
chart->removeAxis(chart->axisX());   // 删除坐标轴
chart->removeAxis(chart->axisY());   // 删除坐标轴

QBarSet *setMath = new QBarSet(theModel->horizontalHeaderItem(1)->text());      // 数学字段
QBarSet *setChinese = new QBarSet(theModel->horizontalHeaderItem(2)->text());   // 语文字段
QBarSet *setEnglish= new QBarSet(theModel->horizontalHeaderItem(3)->text());    // 英语字段

// 创建折线线条
QLineSeries *Line = new QLineSeries();
Line->setName(theModel->horizontalHeaderItem(4)->text());  // 表示平均分
QPen pen;
pen.setColor(Qt::red);  // 使用红色
pen.setWidth(2);        // 设置宽度
Line->setPen(pen);      // 绘制

for(int i=0;i< 10;i++)
{
    // 从数据模型获取数据
    setMath->append(theModel->item(i,1)->text().toInt());            // 数学
    setChinese->append(theModel->item(i,2)->text().toInt());         // 语文
    setEnglish->append(theModel->item(i,3)->text().toInt());         // 英语
    Line->append(QPointF(i,theModel->item(i,4)->text().toFloat()));  // 平均分
}

cppCopy codeQBarSeries *series = new QBarSeries();
series->append(setMath);
series->append(setChinese);
series->append(setEnglish);

chart->addSeries(series);
chart->addSeries(Line);

// 创建柱状图序列 QBarSeries 并添加三个数据集
QBarSeries *series = new QBarSeries();
series->append(setMath);
series->append(setChinese);
series->append(setEnglish);

chart->addSeries(series); // 添加柱状图序列
chart->addSeries(Line);   // 添加折线图序列

// 用于横坐标在字符串列表 即UID
QStringList categories;
for (int i=0;i<10;i++)
{
    categories <<theModel->item(i,0)->text();
}

// 柱状图的坐标轴
QBarCategoryAxis *axisX = new QBarCategoryAxis();
axisX->append(categories);            // 添加横坐标文字列表
chart->setAxisX(axisX, series);       // 设置横坐标
chart->setAxisX(axisX, Line);         // 设置横坐标

// 设置坐标范围
axisX->setRange(categories.at(0), categories.at(categories.count()-1));

// 数值型坐标作为纵轴
QValueAxis *axisY = new QValueAxis;
axisY->setRange(0, 100);
axisY->setTitleText("分数");
axisY->setTickCount(6);
axisY->setLabelFormat("%.0f");

chart->setAxisY(axisY, series);
chart->setAxisY(axisY, Line);
chart->legend()->setVisible(true);
chart->legend()->setAlignment(Qt::AlignBottom);

// 饼图初始化
QChart *chart = new QChart();
chart->setAnimationOptions(QChart::SeriesAnimations);
ui->graphicsView->setChart(chart);
ui->graphicsView->setRenderHint(QPainter::Antialiasing);

// 绘制饼图
chart->removeAllSeries();

// 创建饼图序列
QPieSeries *series = new QPieSeries();

// 饼图中间空心的大小
series->setHoleSize(0.30);

// 添加分块数据
for (int i=0;i<=4;i++)
{
    // 获得QTreeWidgetItem的item
    QTreeWidgetItem* item=ui->treeWidget->topLevelItem(i);

    // 获取分析对象，数学、英语、语文或平均分,添加一个饼图分块数据,标签，数值
    series->append(item->text(0),item->text(1).toFloat());
}

// 饼图分块
QPieSlice *slice;

// 设置每个分块的标签文字
for(int i=0;i<=4;i++)
{
    // 获取分块
    slice =series->slices().at(i);

    // 设置分块的标签
    slice->setLabel(slice->label()+QString::asprintf(": %.0f人, %.1f%%", slice->value(),slice->percentage()*100));

    // 信号与槽函数关联，鼠标落在某个分块上时，此分块弹出
    connect(slice, SIGNAL(hovered(bool)),this, SLOT(on_PieSliceHighlight(bool)));
}

slice->setExploded(true);           // 最后一个设置为exploded
series->setLabelsVisible(true);     // 只影响当前的slices，必须添加完slice之后再设置
chart->addSeries(series);           // 添加饼图序列

chart->legend()->setVisible(true);  // 图例
chart->legend()->setAlignment(Qt::AlignRight);

// 鼠标移入移出时触发hovered信号
void MainWindow::on_PieSliceHighlight(bool show)
{
    QPieSlice *slice;
    slice=(QPieSlice *)sender();

    // 动态设置setExploded效果
    // slice->setLabelVisible(show);
    slice->setExploded(show);
}

// 初始化叠加柱状图绘制窗口
QChart *chart = new QChart();
chart->setAnimationOptions(QChart::SeriesAnimations);
ui->graphicsView->setChart(chart);
ui->graphicsView->setRenderHint(QPainter::Antialiasing);

// 绘制叠加柱状图
chart->removeAllSeries();
chart->removeAxis(chart->axisX());
chart->removeAxis(chart->axisY());

// 创建三门课程的数据集
QBarSet *setMath = new QBarSet(theModel->horizontalHeaderItem(1)->text());
QBarSet *setChinese = new QBarSet(theModel->horizontalHeaderItem(2)->text());
QBarSet *setEnglish= new QBarSet(theModel->horizontalHeaderItem(3)->text());

// 添加前十个分数数据到数据集
for(int i=0;i<20;i++)
{
    setMath->append(theModel->item(i,1)->text().toInt());
    setChinese->append(theModel->item(i,2)->text().toInt());
    setEnglish->append(theModel->item(i,3)->text().toInt());
}

// 创建QStackedBarSeries对象并添加数据集
QStackedBarSeries *series = new QStackedBarSeries();
series->append(setMath);
series->append(setChinese);
series->append(setEnglish);
series->setLabelsVisible(true);

// 添加序列到图表
chart->addSeries(series);

QStringList categories;

// 绘制前十个数据
for (int i=0;i<10;i++)
{
    categories <<theModel->item(i,0)->text();
}

// 类别坐标轴 作为横轴
QBarCategoryAxis *axisX = new QBarCategoryAxis();
axisX->append(categories);
chart->setAxisX(axisX, series);
axisX->setRange(categories.at(0), categories.at(categories.count()-1));

// 数值坐标轴 作为纵轴
QValueAxis *axisY = new QValueAxis;
axisY->setRange(0, 300);
axisY->setTitleText("总分");
axisY->setTickCount(6);
axisY->setLabelFormat("%.0f");
chart->setAxisY(axisY, series);

// 设置图表属性
chart->legend()->setVisible(true);
chart->legend()->setAlignment(Qt::AlignBottom);

// 百分比柱状图初始化
QChart *chart = new QChart();
chart->setAnimationOptions(QChart::SeriesAnimations);
ui->graphicsView->setChart(chart);
ui->graphicsView->setRenderHint(QPainter::Antialiasing);

// 绘制百分比柱状图
chart->removeAllSeries();
chart->removeAxis(chart->axisX());
chart->removeAxis(chart->axisY());

// 创建数据集
QBarSet *setMath = new QBarSet(theModel->horizontalHeaderItem(1)->text());
QBarSet *setChinese = new QBarSet(theModel->horizontalHeaderItem(2)->text());
QBarSet *setEnglish= new QBarSet(theModel->horizontalHeaderItem(3)->text());

QTreeWidgetItem *item;
QStringList categories;

for (int i=0;i<=4;i++)
{
    // 从分数段统计数据表里获取数据添加到数据集
    item=ui->treeWidget->topLevelItem(i);

    // 横坐标的标签
    categories<<item->text(0);

    // 添加数据到QBarSet中
    setMath->append(item->text(1).toFloat());
    setChinese->append(item->text(2).toFloat());
    setEnglish->append(item->text(3).toFloat());
}

// 添加序列
QPercentBarSeries *series = new QPercentBarSeries();
series->append(setMath);
series->append(setChinese);
series->append(setEnglish);
series->setLabelsVisible(true);
series->setLabelsFormat("@value人");
chart->addSeries(series);

// 添加横坐标
QBarCategoryAxis *axisX = new QBarCategoryAxis();
axisX->append(categories);
chart->setAxisX(axisX, series);
axisX->setRange(categories.at(0), categories.at(categories.count()-1));

// 添加纵坐标
QValueAxis *axisY = new QValueAxis;
axisY->setRange(0, 100);
axisY->setTitleText("百分比");
axisY->setTickCount(6);
axisY->setLabelFormat("%.1f");
chart->setAxisY(axisY, series);

// 设置属性
chart->legend()->setVisible(true);
chart->legend()->setAlignment(Qt::AlignRight);

// 散点图初始化
QChart *chart = new QChart();
chart->setAnimationOptions(QChart::SeriesAnimations);
ui->graphicsView->setChart(chart);
ui->graphicsView->setRenderHint(QPainter::Antialiasing);

// 清空绘图区
chart->removeAllSeries();
chart->removeAxis(chart->axisX());
chart->removeAxis(chart->axisY());

// 光滑曲线序列
QSplineSeries *seriesLine = new QSplineSeries();
seriesLine->setName("曲线");
QPen pen;
pen.setColor(Qt::blue);
pen.setWidth(2);
seriesLine->setColor(Qt::blue);
seriesLine->setPen(pen);

// 散点序列
QScatterSeries *series0 = new QScatterSeries();
series0->setName("散点");
series0->setMarkerShape(QScatterSeries::MarkerShapeCircle);
series0->setBorderColor(Qt::black);
series0->setBrush(QBrush(Qt::red));
series0->setMarkerSize(12);

// 随机数种子
qsrand(QTime::currentTime().second());

// 设置曲线随机数
for (int i=0;i<10;i++)
{
    int x=(qrand() % 20);    // 0到20之间的随机数
    int y=(qrand() % 20);
    series0->append(x,y);    // 散点序列
    seriesLine->append(x,y); // 光滑曲线序列
}

chart->addSeries(series0);
chart->addSeries(seriesLine);

// 增加Y坐标轴（可注释）
QValueAxis *axisY = new QValueAxis;
axisY->setRange(0, 20);
axisY->setTitleText("Y坐标");
axisY->setTickCount(11);
axisY->setLabelFormat("%.0f");
axisY->setGridLineVisible(true);
chart->setAxisY(axisY, series0);
chart->setAxisY(axisY, seriesLine);

// 增加X坐标轴（可注释）
QValueAxis *axisX = new QValueAxis;
axisX->setRange(0, 20);
axisX->setTitleText("X");
axisX->setTickCount(11);
axisX->setLabelFormat("%.0f");
axisX->setGridLineVisible(true);
chart->setAxisX(axisX, series0);
chart->setAxisX(axisX, seriesLine);

// 创建缺省的坐标轴（默认缺省值）
chart->createDefaultAxes();
chart->axisX()->setTitleText("X 轴");
chart->axisX()->setRange(-2,22);

chart->axisY()->setTitleText("Y 轴");
chart->axisY()->setRange(-2,22);

chart->legend()->setVisible(true);
chart->legend()->setAlignment(Qt::AlignRight);

// 绑定槽函数，用于点击图例显示与隐藏数据
foreach (QLegendMarker* marker, chart->legend()->markers())
{
    QObject::disconnect(marker, SIGNAL(clicked()), this, SLOT(on_chartBarLegendMarkerClicked()));
    QObject::connect(marker, SIGNAL(clicked()), this, SLOT(on_chartBarLegendMarkerClicked()));
}