In response to the above requirements, I have written a small testing program. 10 curves can be refreshed correctly, but colors cannot be set independently, and there are extra connecting lines between the curves. Can someone help me identify where I went wrong? thank!
pro file
QT += core gui widgets quickwidgets graphs quick
CONFIG += c++17
SOURCES += \
main.cpp \
graphstest.cpp
HEADERS += \
graphstest.h
FORMS += \
graphstest.ui
graphstest.h
#ifndef GRAPHSTEST_H
#define GRAPHSTEST_H
#include <QDateTimeAxis>
#include <QDialog>
#include <QLineSeries>
#include <QValueAxis>
#include <QVector>
QT_BEGIN_NAMESPACE
namespace Ui
{
class graphsTest;
}
QT_END_NAMESPACE
class graphsTest : public QDialog
{
Q_OBJECT
public:
graphsTest(QWidget *parent = nullptr);
~graphsTest();
protected:
void timerEvent(QTimerEvent *evt) override;
private slots:
void on_pushButton_ok_clicked();
private:
Ui::graphsTest *ui;
QDateTimeAxis *m_ax;
QValueAxis *m_ay;
int m_timerEvent;
QVector<QLineSeries *> m_lineSeries;
};
#endif // GRAPHSTEST_H
graphstest.cpp
#include "graphstest.h"
#include <QDateTime>
#include <QDebug>
#include <QQuickItem>
#include "ui_graphstest.h"
graphsTest::graphsTest(QWidget *parent)
: QDialog(parent)
, ui(new Ui::graphsTest)
, m_ax(new QDateTimeAxis(this))
, m_ay(new QValueAxis(this))
, m_timerEvent(0)
{
ui->setupUi(this);
QDateTime dtmNow = QDateTime::currentDateTime();
m_ax->setMin(dtmNow.addDays(-1));
m_ax->setMax(dtmNow);
m_ay->setRange(-100, 100);
QList<QObject *> seriesList;
ui->graphsView->setResizeMode(QQuickWidget::SizeRootObjectToView);
ui->graphsView->setInitialProperties({{"seriesList", QVariant::fromValue(seriesList)},
{"axisX", QVariant::fromValue(m_ax)},
{"axisY", QVariant::fromValue(m_ay)}});
ui->graphsView->loadFromModule("QtGraphs", "GraphsView");
m_timerEvent = startTimer(500);
}
graphsTest::~graphsTest()
{
delete ui;
}
void graphsTest::timerEvent(QTimerEvent *evt)
{
if (evt->timerId() == m_timerEvent)
{
QList<QPointF> data;
QDateTime dtmNow = QDateTime::currentDateTime();
const int N = m_lineSeries.size();
for (int n = 0; n < N; ++n)
{
for (int i = 0; i < 30; ++i)
{
data << QPointF(dtmNow.addSecs(-3600 * 24.0 / 30 * (29 - i)).toMSecsSinceEpoch(),
(rand() % 500 - 250) / 100.0 + n * 16 - 80);
}
m_lineSeries[n]->replace(data);
}
m_ax->setMin(dtmNow.addDays(-1));
m_ax->setMax(dtmNow);
}
}
void graphsTest::on_pushButton_ok_clicked()
{
if (m_lineSeries.size() >= 10)
return;
//Prepare new data
QLineSeries *newLine = new QLineSeries(this);
newLine->setColor(QColor(rand() % 128, rand() % 128, rand() % 128));
//Add to Graph
QVariant seriesListVariant = ui->graphsView->rootObject()->property("seriesList");
if (seriesListVariant.canConvert<QQmlListProperty<QObject>>())
{
QQmlListProperty<QObject> prop = seriesListVariant.value<QQmlListProperty<QObject>>();
prop.append(&prop, newLine);
m_lineSeries.append(newLine);
}
}
graphstest.ui
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>graphsTest</class>
<widget class="QDialog" name="graphsTest">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>579</width>
<height>332</height>
</rect>
</property>
<property name="windowTitle">
<string>graphsTest</string>
</property>
<layout class="QHBoxLayout" name="horizontalLayout">
<item>
<widget class="QQuickWidget" name="graphsView">
<property name="resizeMode">
<enum>QQuickWidget::ResizeMode::SizeRootObjectToView</enum>
</property>
</widget>
</item>
<item>
<layout class="QVBoxLayout" name="verticalLayout">
<property name="sizeConstraint">
<enum>QLayout::SizeConstraint::SetMaximumSize</enum>
</property>
<item>
<widget class="QPushButton" name="pushButton_ok">
<property name="sizePolicy">
<sizepolicy hsizetype="Fixed" vsizetype="Fixed">
<horstretch>0</horstretch>
<verstretch>0</verstretch>
</sizepolicy>
</property>
<property name="text">
<string>Add Serials</string>
</property>
</widget>
</item>
<item>
<spacer name="verticalSpacer">
<property name="sizePolicy">
<sizepolicy hsizetype="Fixed" vsizetype="Expanding">
<horstretch>0</horstretch>
<verstretch>0</verstretch>
</sizepolicy>
</property>
<property name="orientation">
<enum>Qt::Orientation::Vertical</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>20</width>
<height>40</height>
</size>
</property>
</spacer>
</item>
</layout>
</item>
</layout>
</widget>
<customwidgets>
<customwidget>
<class>QQuickWidget</class>
<extends>QWidget</extends>
<header location="global">QtQuickWidgets/QQuickWidget</header>
</customwidget>
</customwidgets>
<resources/>
<connections/>
</ui>
main.cpp
#include "graphstest.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
graphsTest w;
w.show();
return a.exec();
}
Qt 6.9.1 Mingw64 in windows 11:
[image: b7ce4b6c-16e4-4775-8b16-dec3fe4c06ab.png]
Further more, how to add a rubber-band selection tool and connect QML signals to the C++ slots, is a bit hard for me . I'll try it later.
And, the example above shows a blank screen in VirtualBox , with 3D checkbox checked . It only worked in real machines. It seems that D3D backend is not good in VMs.
