1、 Use

Official website ：http://www.qcustomplot.com/

hold qcustomplot.cpp and qcustomplot.h Copy to the project directory , Then, the two files are introduced into the project, and the existing files can be added by right clicking in the project , Add two files to the project . At this time pro The file will be added qcustomplot.cpp and qcustomplot.h, What needs to be added at this time is

QT += widgets printsupport

stay UI Drag the file into a Widget, Name it Plot , Operations in subsequent procedures qcustomplot It's all him . Then promoted to QCustomPlot,.h The file with the same name automatically becomes lowercase

2、 mapping

    ui->Plot->addGraph();// Add curves 
    ui->Plot->graph(0)->setPen(QPen(Qt::blue));// Set the curve color 
    qDebug()<<ui->Plot->graph(0)->name();// Read curve name     Because it is not set now , The read name is  "Graph 1"
    ui->Plot->graph(0)->setName(QString("New graph "));// Set curve name     Now read again is New graph 
    ui->Plot->graph(0)->setData(x, y0);// Write data 
	ui->Plot->graph(0)->addData(x,y0);// Add data 
	ui->Plot->graph(0)->data().data()->clear();// Clear the data retention curve 
/* Axis */
    ui->Plot->xAxis2->setVisible(true);// Display above X Axis 
    ui->Plot->xAxis2->setTickLabels(true);// Display above X Axis   scale 
    ui->Plot->yAxis2->setVisible(true);// Show the right side Y Axis 
    ui->Plot->yAxis2->setTickLabels(false);// Do not display the right side Y Axis   scale 
    ui->Plot->xAxis->setVisible(true);// Show below X Axis 
    ui->Plot->xAxis->setTickLabels(true);// Show below X Axis   scale 
    ui->Plot->yAxis->setVisible(true);// Display left side Y Axis 
    ui->Plot->yAxis->setTickLabels(false);// Do not show left side Y Axis   scale 
    ui->Plot->setInteractions(QCP::iRangeDrag | QCP::iRangeZoom | QCP::iSelectPlottables);// Zoom in, drag, select, etc 
	ui->Plot->xAxis->setRange(0, 100);                         // At present X The range of the axis display 
	ui->Plot->yAxis->setRange(0, 10);                          // At present Y The range of the axis display 	
	ui->Plot->graph(0)->rescaleAxes();// Axis adaptation 	
ui->Plot->graph(1)->rescaleAxes(ture);//nlyEnlarge  Default false, Indicates that the range can be reduced or enlarged , If true Can only be magnified , Without narrowing the scope .
	// Since the adaptive axis will only change the lower and left axes , This ensures consistency from top to bottom , Right and left 
     connect(ui->Plot->xAxis, SIGNAL(rangeChanged(QCPRange)), ui->Plot->xAxis2, SLOT(setRange(QCPRange)));
     connect(ui->Plot->yAxis, SIGNAL(rangeChanged(QCPRange)), ui->Plot->yAxis2, SLOT(setRange(QCPRange)));
     QCPRange XAxis_Range=ui->Plot->xAxis->range();// Get the value of the coordinate axis before adjustment 
/* legend */
	ui->Plot->legend->setVisible(true);// Set the legend visible 
//  Set the routine priority of the diagram     The default icons are arranged vertically , This is horizontal 
    ui->Plot->legend->setFillOrder(QCPLayoutGrid::foColumnsFirst);
//  Set six legend auto wrap 
    ui->Plot->legend->setWrap(6);
//  Set legend position , The selection here is displayed in QCPAxisRect below , Similarly, it can be set to display in QCustomPlot Anywhere in , And proportion 
    ui->Plot->plotLayout()->addElement(1 , 0, ui->Plot->legend);
//  Set the display scale , The size of the box where the legend is located 
    ui->Plot->plotLayout()->setRowStretchFactor(1, 0.001);
//  Set border hide , There is a frame between the legend and the curve 
    ui->Plot->legend->setBorderPen(Qt::NoPen);

// Zoom in, drag, select, etc 
enum Interaction { iRangeDrag         = 0x001 // Left click to drag 
                   ,iRangeZoom        = 0x002 // The range can be scaled with the mouse wheel 
                   ,iMultiSelect      = 0x004 // Select multiple curves in the 
                   ,iSelectPlottables = 0x008 // Lines can be selected 
                   ,iSelectAxes       = 0x010 // Axes are optional 
                   ,iSelectLegend     = 0x020 // Legend is optional 
                   ,iSelectItems      = 0x040 // Optional items （ rectangular 、 arrow 、 Text items, etc 
                   ,iSelectOther      = 0x080 // All other objects are optional 
                 };

    // Set canvas background color 
        QLinearGradient plotGradient;
        plotGradient.setStart(0, 0);
        plotGradient.setFinalStop(0, 350);
        plotGradient.setColorAt(0, QColor(80, 80, 80));
        plotGradient.setColorAt(1, QColor(50, 50, 50));
    ui->Plot->setBackground(plotGradient);

3. Expand functions

3.1 Set the legend to synchronize with the curve

stay maindows in , Define the slot function selectionChanged.

//H file 
private slots:
    void selectionChanged();
//cpp file 
void MainWindow::selectionChanged()
{
      //  Synchronize the selection of graphics and the selection of corresponding legend items :
      for (int i=0; i<ui->Plot->graphCount(); ++i)
      {
        QCPGraph *graph = ui->Plot->graph(i);
        QCPPlottableLegendItem *item = ui->Plot->legend->itemWithPlottable(graph);
        if (item->selected() || graph->selected())
        {
          item->setSelected(true);        // Complete legend selection 
          graph->setSelection(QCPDataSelection(graph->data()->dataRange())); // Complete the curve selection 
        }
      }
}
//MainWindow Link signal and slot function in function 
connect(ui->Plot, SIGNAL(selectionChangedByUser()), this, SLOT(selectionChanged()));

3.2 Change the original left key translation full key area zoom to left key translation , Right click zoom

1、 Because the official default left button is the translation curve , Let's change the pan function to right click first （ Or the middle key of the scroll wheel , According to your preference ） Up , Directly in this function
void QCPAxisRect::mousePressEvent(QMouseEvent *event, const QVariant &details) Just change it , hold Qt::LeftButton Change to Qt::RightButton that will do .

2、 stay QCustomPlot Class private Variable ：( searchable class QCP_LIB_DECL QCustomPlot)

private:
  QRubberBand *rb;
  QPoint startPos;
  bool cancelRb;

3、 stay QCustomPlot Of 3 Add code to a mouse event function

//0、 In the constructor QCustomPlot::QCustomPlot(QWidget *parent) Add... To the initialization list of ：
  ,rb(new QRubberBand(QRubberBand::Rectangle, this))
  ,startPos(0, 0)
//1、 When the left key is pressed , Record the coordinate starting point 
     stay QCustomPlot::mousePressEvent(QMouseEvent *event) Add ：
    if(event->buttons() & Qt::LeftButton)
    {
        startPos = event->pos();
        cancelRb = false;
        rb->resize(0, 0);
        rb->show();
    }
 
//2、 When the left key is pressed and moved , Draw rectangle 
     stay void QCustomPlot::mouseMoveEvent(QMouseEvent *event) Add ：
 
    if(event->buttons() & Qt::LeftButton)
    {
        QRect normalRect = QRect(startPos, event->pos()).normalized();// Any two points define a rectangle 
        rb->setGeometry(normalRect);
    }
//3、 When the left button pops up , Record end coordinates , And enlarge the curve to 【 The starting point 、 End 】 In a rectangular box surrounded by 
     stay void QCustomPlot::mouseReleaseEvent(QMouseEvent *event) Add ：
 
    if(event->button() == Qt::LeftButton)
    {
        rb->hide();
        if(!cancelRb)
        {
            QRect normalRect = QRect(startPos, event->pos()).normalized();
            rb->setGeometry(normalRect);
            this->xAxis->setRange(xAxis->pixelToCoord(normalRect.left()),
                                  xAxis->pixelToCoord(normalRect.right()));
 
            this->yAxis->setRange(yAxis->pixelToCoord(normalRect.bottom()),
                                  yAxis->pixelToCoord(normalRect.top()));
            this->replot();// Refresh the image now 
        }
    }

3.3 Axis oscilloscope type movement

             /* Set up X Shaft fixed length , Oscilloscope propulsion */
             if(ui->spinBox_X_Lenth->value()!=0)
             {
                 QCPRange XAxis_Range=ui->Plot->xAxis->range();// Get the value of the coordinate axis before adjustment 
                 if(XAxis_Range.upper-XAxis_Range.lower>ui->spinBox_X_Lenth->value())
                 {
                    XAxis_Range.lower=XAxis_Range.upper-ui->spinBox_X_Lenth->value();
                    ui->Plot->xAxis->setRange(XAxis_Range);
                 }
             }

3.4 Change the curve style

/* routine */
connect(ui->spinBox_Line_Style_Point_Size,static_cast<void (QSpinBox::*)(const QString &)>(&QSpinBox::valueChanged),[=](){
        ui->Plot->graph(ui->comboBox_Line_Style_LineNum->currentIndex())->setScatterStyle(QCPScatterStyle(QCPScatterStyle::ScatterShape(ui->comboBox_Line_Style_Point->currentIndex()),ui->spinBox_Line_Style_Point_Size->value()));
        ui->Plot->replot();
    });
/* notes */
QCPScatterStyle::ScatterShape(ui->comboBox_Line_Style_Point->currentIndex() Corresponding 
==》QCPScatterStyle::ssDisc// This is the way to take enumeration     QCPScatterStyle class ScatterShape
/* primary */ 
ui->Plot->graph(0)->setScatterStyle(QCPScatterStyle(QCPScatterStyle::ssDisc,5));
//QCPScatterStyle::ssDisc Point style 
setScatterStyle(QCPScatterStyle( Point style , Point size ));