qt5.12绘制折线图

在Qt5.12中，可以使用Qt Charts模块来绘制折线图。以下是一个简单的示例：

1. 首先，在.pro文件中添加Qt Charts模块的引用：

QT += charts

2. 在代码中创建一个QChart对象，并将其添加到QChartView中：

QChart *chart = new QChart();
QChartView *chartView = new QChartView(chart);

3. 创建一个QLineSeries对象并添加数据点：

QLineSeries *series = new QLineSeries();
series->append(0, 6);
series->append(2, 4);
series->append(3, 8);
series->append(7, 4);
series->append(10, 5);

4. 将QLineSeries对象添加到QChart对象中：

chart->addSeries(series);

5. 创建一个QValueAxis对象并将其添加到QChart对象中：

QValueAxis *axisX = new QValueAxis;
axisX->setRange(0, 10);
axisX->setLabelFormat("%.0f");
axisX->setTitleText("X Axis");
chart->addAxis(axisX, Qt::AlignBottom);

QValueAxis *axisY = new QValueAxis;
axisY->setRange(0, 10);
axisY->setLabelFormat("%.2f");
axisY->setTitleText("Y Axis");
chart->addAxis(axisY, Qt::AlignLeft);

series->attachAxis(axisX);
series->attachAxis(axisY);

6. 显示QChartView：

chartView->show();

完整的示例代码如下所示：

#include <QApplication>
#include <QtCharts/QChartView>
#include <QtCharts/QLineSeries>
#include <QtCharts/QValueAxis>

QT_CHARTS_USE_NAMESPACE

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QChart *chart = new QChart();
    QChartView *chartView = new QChartView(chart);
    chartView->setRenderHint(QPainter::Antialiasing);

    QLineSeries *series = new QLineSeries();
    series->append(0, 6);
    series->append(2, 4);
    series->append(3, 8);
    series->append(7, 4);
    series->append(10, 5);

    chart->addSeries(series);

    QValueAxis *axisX = new QValueAxis;
    axisX->setRange(0, 10);
    axisX->setLabelFormat("%.0f");
    axisX->setTitleText("X Axis");
    chart->addAxis(axisX, Qt::AlignBottom);

    QValueAxis *axisY = new QValueAxis;
    axisY->setRange(0, 10);
    axisY->setLabelFormat("%.2f");
    axisY->setTitleText("Y Axis");
    chart->addAxis(axisY, Qt::AlignLeft);

    series->attachAxis(axisX);
    series->attachAxis(axisY);

    chartView->show();

    return a.exec();
}