can't open ther serialport

[nanor]

Hi everyone
I am working on a project where I have to write to an read from a serial port. I have written the following code, but I am getting the message "can't open the port" in my else statement.
When I use hercules, I can open the "COM1" port. But I don't know why can't I open this port via my QT program.

code:

widget.h:

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QtSerialPort/QSerialPort>

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = nullptr);
    ~Widget();

    QSerialPort *serial;

private slots:
    void on_pushButton_clicked();


private:
    Ui::Widget *ui;
};

#endif // WIDGET_H

widget.cpp:

#include "widget.h"
#include "ui_widget.h"
#include <QDebug>
#include <QtSerialPort/QSerialPort>
#include <QSerialPortInfo>

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
        ui->setupUi(this);

        serial = new QSerialPort(this);

        serial->setPortName("COM1");

        for(const auto &serialPortInfo : QSerialPortInfo::availablePorts())
        {
                qDebug() << "find serial port: " << serialPortInfo.portName() ;
        }

        serial->open(QIODevice::ReadWrite);

        if(serial->open(QIODevice::ReadWrite))
        {
            serial->setBaudRate(QSerialPort::Baud9600);
            serial->setDataBits(QSerialPort::Data8);
            serial->setParity(QSerialPort::NoParity);
            serial->setStopBits(QSerialPort::OneStop);
            serial->setFlowControl(QSerialPort::NoFlowControl);

            
           
            serial->write("ok");
            qDebug() << " Reading " << serial->read(1);
            serial->flush();

           
        }

        else
        {
          qDebug() << "can't open the port";
        }

}

Widget::~Widget()
{
    delete ui;
    serial->close();
}

void Widget::on_pushButton_clicked()
{
    qDebug() << "salam";
}

main.cpp:

#include "widget.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    w.show();

    return a.exec();
}

[JonB]

@nanor
You (try to) open the port twice. Presumably the second open fails because it's already open from the first one? At least that's the first thing to fix.

[nanor]

@JonB I closed hercules. the port isn't opened now by hercules. But I still can't open the port from QT

[nanor]

@JonB Sorry. Yes you are right. In my code, I have to write if(serial->isOpen()) instead of open. Now it works well. Thank you