modify a QML Text from C++

[neda]

MySerialPort::readData() runs in a worker thread, it can't instantiate UI elements.

The cleanest way would be to have a model for the strings and use a Repeater in your main.qml to create MyItem instances for each model entry.

The model would need a slot that takes a string and appends it to its data.

You would then connect this slot to a signal in your serial port class which is emitted when it has received a new string.

Cheers,
_

Thanks for your reply.
Please guide me with simple code.

I change my code but I don't see any change to text control.
main.cpp:

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
 
    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
 
    MySerialPort iSerialPort;
QThread* thread = new QThread(app);
 iSerialPort.moveToThread(thread);
thread->start();
    iSerialPort.myText= engine.rootObjects().at(0)->findChild<QObject*>("text1Text");
    iSerialPort.openSerialPort();
 
    return app.exec();
}

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

    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

    MySerialPort iSerialPort;
QThread* thread = new QThread(app);
 iSerialPort.moveToThread(thread);
thread->start();
    iSerialPort.myText= engine.rootObjects().at(0)->findChild<QObject*>("text1Text");
    iSerialPort.openSerialPort();

    return app.exec();
}

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serialport.cpp:

void MySerialPort::readData()
{
    QByteArray data = serial->readAll();
 
    qDebug() << data;
 
 
    myText->setProperty("text", data);
}

void MySerialPort::readData()
{
    QByteArray data = serial->readAll();

    qDebug() << data;


    myText->setProperty("text", data);
}

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myserialport.h

#ifndef MYSERIALPORT_H
#define MYSERIALPORT_H
#include <QtSerialPort/QtSerialPort>
#include <QObject>
#include <QApplication>
#include <QQmlApplicationEngine>
 
class MySerialPort: public QSerialPort
{
     Q_OBJECT
public:
    MySerialPort();
    QObject *myText;
 
public slots:
    void openSerialPort();
    void closeSerialPort();
 
    void writeData(const QByteArray &data);
    void readData();
 
    void handleError(QSerialPort::SerialPortError error);
 
private:
    void showStatusMessage(const QString &message);
 
    QSerialPort *serial;
 
};
 
#endif // MYSERIALPORT_H

#ifndef MYSERIALPORT_H
#define MYSERIALPORT_H
#include <QtSerialPort/QtSerialPort>
#include <QObject>
#include <QApplication>
#include <QQmlApplicationEngine>

class MySerialPort: public QSerialPort
{
     Q_OBJECT
public:
    MySerialPort();
    QObject *myText;

public slots:
    void openSerialPort();
    void closeSerialPort();

    void writeData(const QByteArray &data);
    void readData();

    void handleError(QSerialPort::SerialPortError error);

private:
    void showStatusMessage(const QString &message);

    QSerialPort *serial;

};

#endif // MYSERIALPORT_H

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main.qml:

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")
 
 
    Text {
        id: text1Text
        objectName: text1Text
        width: 400
        height: 29
        color: "red"
        text: "This text should change..."
        font.pixelSize: 12
    }
 
}

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")


    Text {
        id: text1Text
        objectName: text1Text
        width: 400
        height: 29
        color: "red"
        text: "This text should change..."
        font.pixelSize: 12
    }

}

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