Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. Help me
Forum Updated to NodeBB v4.3 + New Features

Help me

Scheduled Pinned Locked Moved Solved General and Desktop
14 Posts 6 Posters 767 Views 2 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • Q Qt fa schifo

    Hi everyone,
    I'm learning to use Qt but with a lot of difficulty. I created a TCP network connection but it doesn't work and I can't fix the code. Would some good soul help me?

    mytcpsocket.h

    #include <QtNetwork/QTcpSocket>
#include <QtNetwork/QAbstractSocket>
#include <QDebug>

QT_BEGIN_NAMESPACE
namespace Ui {
class MyTcpSocket;
}
QT_END_NAMESPACE

class MyTcpSocket : public QMainWindow
{
    Q_OBJECT

public:
    MyTcpSocket(QWidget *parent = nullptr);
    ~MyTcpSocket();
    //    void doConnect();

private slots:
    void on_cmdinvia_clicked();

    void on_cmdconnetti_clicked();

public slots:
    void doConnect();
    void connected();
    void disconnected();
    void bytesWritten(qint64 bytes);
    void readyRead();
   // void subinviadato();
    void subinviadatotest();

private:
    Ui::MyTcpSocket *ui;
        QTcpSocket *socket;


};
#endif // MYTCPSOCKET_H

    main.cpp

    #include "mytcpsocket.h"

#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MyTcpSocket w;
    w.show();
    return a.exec();
}

    mytcpsocket.cpp

    #include "mytcpsocket.h"
#include "ui_mytcpsocket.h"
#include "QTimer"
#include <QThread>
#include <QString>
#include <QObject>
#include <QtNetwork/QTcpSocket>
#include <QtNetwork/QAbstractSocket>
#include <QDebug>
#include <QtWidgets>

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

MyTcpSocket::~MyTcpSocket()
{
    delete ui;
}

void MyTcpSocket::on_cmdinvia_clicked()
{
    subinviadatotest();
}


void MyTcpSocket::on_cmdconnetti_clicked()
{
    readyRead();
    doConnect();
}

//void subinviadato();


//MyTcpSocket::MyTcpSocket(QObject *parent) :
//    QObject(parent)
//{
//}


void MyTcpSocket::doConnect()
{
    //socket = new QTcpSocket(this); //NON FUNZIONA
    //QTcpSocket socket;

    connect(socket, SIGNAL(connected()),this, SLOT(connected()));
    connect(socket, SIGNAL(disconnected()),this, SLOT(disconnected()));
    //connect(socket, SIGNAL(bytesWritten(1)),this, SLOT(bytesWritten(1)));
    connect(socket, SIGNAL(readyRead()),this, SLOT(readyRead()));

    qDebug() << "connecting...";

    // this is not blocking call
    socket->connectToHost("192.168.1.26", 88);

    // we need to wait...
    if(!socket->waitForConnected(5000))
    {
        qDebug() << "Error: " << socket->errorString();
    }
}

void MyTcpSocket::connected()
{
    qDebug() << "connected...";

     subinviadatotest();

}

void MyTcpSocket::subinviadatotest()
{
    //Dichiaro variabili che uso;
    QChar str;
    QString stringa;
    stringa = "{P01-P07-DAT-AXX}";
    long lunghezza;

    // (const char *)&str << stringa.at(stringa.length() - 2);
    //qDebug() str;

    //Misuro lunghezza stringhe
    lunghezza=stringa.length();

    //Visualizzo informazioni
    qDebug("  ---  ");
    QString ss = QString::number(lunghezza);
    qDebug() << ss;
    qDebug("  ---  ");

    long i;
    for(i=0;i<lunghezza;i++) {

        //if(stringa[i]=='}')
        //    break;
        QChar caratt;
        caratt=stringa[i];
        //qDebug("-");
        //qDebug() << caratt;
        str= caratt; //QChar('{');
        //const char *str = qPrintable(stringa);

        socket->write((const char *)&str, 1);
        socket->waitForBytesWritten(1000);
        QThread::msleep(100);

    }


}



void MyTcpSocket::disconnected()
{
    qDebug() << "disconnected...";
}

void MyTcpSocket::bytesWritten(qint64 bytes)
{
    qDebug() << bytes << " bytes written...";
}

void MyTcpSocket::readyRead()
{
    qDebug() << "reading...";

    // read the data from the socket
    qDebug() << socket->readAll();
}

    mytcpsocket.ui

    <?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MyTcpSocket</class>
 <widget class="QMainWindow" name="MyTcpSocket">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MyTcpSocket</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QPushButton" name="cmdinvia">
    <property name="geometry">
     <rect>
      <x>600</x>
      <y>490</y>
      <width>181</width>
      <height>29</height>
     </rect>
    </property>
    <property name="text">
     <string>Invia</string>
    </property>
   </widget>
   <widget class="QLineEdit" name="txtinvia">
    <property name="geometry">
     <rect>
      <x>30</x>
      <y>490</y>
      <width>561</width>
      <height>26</height>
     </rect>
    </property>
   </widget>
   <widget class="QTextEdit" name="txtricevuto">
    <property name="geometry">
     <rect>
      <x>30</x>
      <y>60</y>
      <width>751</width>
      <height>421</height>
     </rect>
    </property>
   </widget>
   <widget class="QPushButton" name="cmdconnetti">
    <property name="geometry">
     <rect>
      <x>520</x>
      <y>10</y>
      <width>231</width>
      <height>41</height>
     </rect>
    </property>
    <property name="text">
     <string>Connetti</string>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>26</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

    I use Qt 12.0.2 with 6.6.2 min gw

    Ronel_qtmasterR Offline
    Ronel_qtmasterR Offline
    Ronel_qtmaster
    wrote on last edited by
    #2

    @Qt-fa-schifo hi and welcome to qt forum.As You are a beginner, i would advice you to check this https://www.bogotobogo.com/Qt/Qt5_QTcpSocket_Signals_Slots.php

    1 Reply Last reply
    0
    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #3

      Hi and welcome to devnet,

      Beside the recommendation of @Ronel_qtmaster, you commented out the line where you create the QTcpSocket object so it can't even start to work.

      Interested in AI ? www.idiap.ch
      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

      1 Reply Last reply
      1
      • Q Qt fa schifo

        Hi everyone,
        I'm learning to use Qt but with a lot of difficulty. I created a TCP network connection but it doesn't work and I can't fix the code. Would some good soul help me?

        mytcpsocket.h

        #include <QtNetwork/QTcpSocket>
#include <QtNetwork/QAbstractSocket>
#include <QDebug>

QT_BEGIN_NAMESPACE
namespace Ui {
class MyTcpSocket;
}
QT_END_NAMESPACE

class MyTcpSocket : public QMainWindow
{
    Q_OBJECT

public:
    MyTcpSocket(QWidget *parent = nullptr);
    ~MyTcpSocket();
    //    void doConnect();

private slots:
    void on_cmdinvia_clicked();

    void on_cmdconnetti_clicked();

public slots:
    void doConnect();
    void connected();
    void disconnected();
    void bytesWritten(qint64 bytes);
    void readyRead();
   // void subinviadato();
    void subinviadatotest();

private:
    Ui::MyTcpSocket *ui;
        QTcpSocket *socket;


};
#endif // MYTCPSOCKET_H

        main.cpp

        #include "mytcpsocket.h"

#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MyTcpSocket w;
    w.show();
    return a.exec();
}

        mytcpsocket.cpp

        #include "mytcpsocket.h"
#include "ui_mytcpsocket.h"
#include "QTimer"
#include <QThread>
#include <QString>
#include <QObject>
#include <QtNetwork/QTcpSocket>
#include <QtNetwork/QAbstractSocket>
#include <QDebug>
#include <QtWidgets>

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

MyTcpSocket::~MyTcpSocket()
{
    delete ui;
}

void MyTcpSocket::on_cmdinvia_clicked()
{
    subinviadatotest();
}


void MyTcpSocket::on_cmdconnetti_clicked()
{
    readyRead();
    doConnect();
}

//void subinviadato();


//MyTcpSocket::MyTcpSocket(QObject *parent) :
//    QObject(parent)
//{
//}


void MyTcpSocket::doConnect()
{
    //socket = new QTcpSocket(this); //NON FUNZIONA
    //QTcpSocket socket;

    connect(socket, SIGNAL(connected()),this, SLOT(connected()));
    connect(socket, SIGNAL(disconnected()),this, SLOT(disconnected()));
    //connect(socket, SIGNAL(bytesWritten(1)),this, SLOT(bytesWritten(1)));
    connect(socket, SIGNAL(readyRead()),this, SLOT(readyRead()));

    qDebug() << "connecting...";

    // this is not blocking call
    socket->connectToHost("192.168.1.26", 88);

    // we need to wait...
    if(!socket->waitForConnected(5000))
    {
        qDebug() << "Error: " << socket->errorString();
    }
}

void MyTcpSocket::connected()
{
    qDebug() << "connected...";

     subinviadatotest();

}

void MyTcpSocket::subinviadatotest()
{
    //Dichiaro variabili che uso;
    QChar str;
    QString stringa;
    stringa = "{P01-P07-DAT-AXX}";
    long lunghezza;

    // (const char *)&str << stringa.at(stringa.length() - 2);
    //qDebug() str;

    //Misuro lunghezza stringhe
    lunghezza=stringa.length();

    //Visualizzo informazioni
    qDebug("  ---  ");
    QString ss = QString::number(lunghezza);
    qDebug() << ss;
    qDebug("  ---  ");

    long i;
    for(i=0;i<lunghezza;i++) {

        //if(stringa[i]=='}')
        //    break;
        QChar caratt;
        caratt=stringa[i];
        //qDebug("-");
        //qDebug() << caratt;
        str= caratt; //QChar('{');
        //const char *str = qPrintable(stringa);

        socket->write((const char *)&str, 1);
        socket->waitForBytesWritten(1000);
        QThread::msleep(100);

    }


}



void MyTcpSocket::disconnected()
{
    qDebug() << "disconnected...";
}

void MyTcpSocket::bytesWritten(qint64 bytes)
{
    qDebug() << bytes << " bytes written...";
}

void MyTcpSocket::readyRead()
{
    qDebug() << "reading...";

    // read the data from the socket
    qDebug() << socket->readAll();
}

        mytcpsocket.ui

        <?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MyTcpSocket</class>
 <widget class="QMainWindow" name="MyTcpSocket">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MyTcpSocket</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QPushButton" name="cmdinvia">
    <property name="geometry">
     <rect>
      <x>600</x>
      <y>490</y>
      <width>181</width>
      <height>29</height>
     </rect>
    </property>
    <property name="text">
     <string>Invia</string>
    </property>
   </widget>
   <widget class="QLineEdit" name="txtinvia">
    <property name="geometry">
     <rect>
      <x>30</x>
      <y>490</y>
      <width>561</width>
      <height>26</height>
     </rect>
    </property>
   </widget>
   <widget class="QTextEdit" name="txtricevuto">
    <property name="geometry">
     <rect>
      <x>30</x>
      <y>60</y>
      <width>751</width>
      <height>421</height>
     </rect>
    </property>
   </widget>
   <widget class="QPushButton" name="cmdconnetti">
    <property name="geometry">
     <rect>
      <x>520</x>
      <y>10</y>
      <width>231</width>
      <height>41</height>
     </rect>
    </property>
    <property name="text">
     <string>Connetti</string>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>26</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

        I use Qt 12.0.2 with 6.6.2 min gw

        JonBJ Offline
        JonBJ Offline
        JonB
        wrote on last edited by JonB
        #4

        @Qt-fa-schifo
        The first thing is to define/explain to us what "but it doesn't work" means exactly.

        What was the problem with

        //socket = new QTcpSocket(this); //NON FUNZIONA

        How did it "not work"? As @SGaist says that is needed to create the socket.

        And I suspect you are working from https://www.bogotobogo.com/Qt/Qt5_QTcpSocket_Signals_Slots.php. It helps if you say so.

        There is another Qt example at https://doc.qt.io/qt-6/qtnetwork-fortuneclient-example.html, just so you know. However for now you probably want to stick with one you have started on.

        1 Reply Last reply
        1
        • Q Offline
          Q Offline
          Qt fa schifo
          wrote on last edited by
          #5

          what I can't understand is why if I activate socket = new QTcpSocket(this); the program gives me the following error:

          :-1: error: debug/mytcpsocket.o: in function MyTcpSocket::doConnect()': C:........\Qt\esempio3\untitled\mytcpsocket.cpp:47: error: undefined reference to __imp__ZN10QTcpSocketC1EP7QObject'
          :-1: error: collect2.exe: error: ld returned 1 exit status
          :-1: warning: The build directory is not at the same level as the source directory, which could be the reason for the build failure.
          :-1: error: [Makefile.Debug:72: debug/untitled.exe] Error 1

          while if I leave it deactivated the program starts and then crashes.

          it should be the other way around, I don't understand....

          Ronel_qtmasterR JonBJ 2 Replies Last reply
          0
          • Q Qt fa schifo

            what I can't understand is why if I activate socket = new QTcpSocket(this); the program gives me the following error:

            :-1: error: debug/mytcpsocket.o: in function MyTcpSocket::doConnect()': C:........\Qt\esempio3\untitled\mytcpsocket.cpp:47: error: undefined reference to __imp__ZN10QTcpSocketC1EP7QObject'
            :-1: error: collect2.exe: error: ld returned 1 exit status
            :-1: warning: The build directory is not at the same level as the source directory, which could be the reason for the build failure.
            :-1: error: [Makefile.Debug:72: debug/untitled.exe] Error 1

            while if I leave it deactivated the program starts and then crashes.

            it should be the other way around, I don't understand....

            Ronel_qtmasterR Offline
            Ronel_qtmasterR Offline
            Ronel_qtmaster
            wrote on last edited by
            #6

            @Qt-fa-schifo following your code, it seems you don't even understand to basic syntax
            here:
            socket = new QTcpSocket(this); //NON FUNZIONA
            QTcpSocket socket;
            you are creating two different sockets with the same name.
            please when begining you should follow official exemples.Simply follow the link i sent you

            1 Reply Last reply
            0
            • Q Offline
              Q Offline
              Qt fa schifo
              wrote on last edited by
              #7

              that was a comment from another example and it was disabled so it doesn't cause the program to not work.
              If I create a new project and paste the bogotobogo examples into it they don't work.
              version incompatibility?

              1 Reply Last reply
              0
              • Q Qt fa schifo

                what I can't understand is why if I activate socket = new QTcpSocket(this); the program gives me the following error:

                :-1: error: debug/mytcpsocket.o: in function MyTcpSocket::doConnect()': C:........\Qt\esempio3\untitled\mytcpsocket.cpp:47: error: undefined reference to __imp__ZN10QTcpSocketC1EP7QObject'
                :-1: error: collect2.exe: error: ld returned 1 exit status
                :-1: warning: The build directory is not at the same level as the source directory, which could be the reason for the build failure.
                :-1: error: [Makefile.Debug:72: debug/untitled.exe] Error 1

                while if I leave it deactivated the program starts and then crashes.

                it should be the other way around, I don't understand....

                JonBJ Offline
                JonBJ Offline
                JonB
                wrote on last edited by JonB
                #8

                @Qt-fa-schifo
                If you do not have line socket = new QTcpSocket(this); then socket will be uninitialized and your program would be expected to crash.

                You do need socket = new QTcpSocket(this); . The error you show is a linker error. You are either not linking with the right libraries, or possibly the wrong version.

                I see you are MinGW, are you using qmake or cmake?

                1 Reply Last reply
                0
                • Q Offline
                  Q Offline
                  Qt fa schifo
                  wrote on last edited by
                  #9

                  I'm using qmake.

                  in effect with the original libraries

                  #include <QTcpSocket>
                  #include <QAbstractSocket>

                  give me error (file not found), I thought maybe are moved:

                  #include <QtNetwork/QTcpSocket>
                  #include <QtNetwork/QAbstractSocket>

                  so could this is the problem?
                  How do I find the right QTcpSocket and QAbstractSocket?

                  Q 1 Reply Last reply
                  0
                  • Q Qt fa schifo

                    I'm using qmake.

                    in effect with the original libraries

                    #include <QTcpSocket>
                    #include <QAbstractSocket>

                    give me error (file not found), I thought maybe are moved:

                    #include <QtNetwork/QTcpSocket>
                    #include <QtNetwork/QAbstractSocket>

                    so could this is the problem?
                    How do I find the right QTcpSocket and QAbstractSocket?

                    Q Offline
                    Q Offline
                    Qt fa schifo
                    wrote on last edited by
                    #10

                    I changed compiler but the error is still the same...

                    C H 2 Replies Last reply
                    0
                    • Q Qt fa schifo

                      I changed compiler but the error is still the same...

                      C Offline
                      C Offline
                      ChrisW67
                      wrote on last edited by
                      #11

                      @Qt-fa-schifo In your PRO file do you have:

                      QT += network

                      See Qt Network

                      Q 1 Reply Last reply
                      0
                      • Q Qt fa schifo

                        I changed compiler but the error is still the same...

                        H Offline
                        H Offline
                        Helmut.Jakoby
                        wrote on last edited by
                        #12

                        Hello my dear @Qt-is-shit (translation by @Qt-fa-schifo from Italian).
                        If so, why are you using Qt? And do you think you can get better answers with this nickname?

                        https://www.globalobjects.de/

                        1 Reply Last reply
                        0
                        • C ChrisW67

                          @Qt-fa-schifo In your PRO file do you have:

                          QT += network

                          See Qt Network

                          Q Offline
                          Q Offline
                          Qt fa schifo
                          wrote on last edited by
                          #13

                          @ChrisW67 thank you very very very very very very very very very much

                          JonBJ 1 Reply Last reply
                          0
                          • Q Qt fa schifo

                            @ChrisW67 thank you very very very very very very very very very much

                            JonBJ Offline
                            JonBJ Offline
                            JonB
                            wrote on last edited by
                            #14

                            @Qt-fa-schifo
                            Just so you know: if you had showed your .pro from the start or said you were using qmake we could have guessed you were missing QT += network, that is why I asked whether you were qmake or cmake.

                            1 Reply Last reply
                            0
                            • Q Qt fa schifo has marked this topic as solved on

                            • Login
                            • Login or register to search.
                            • First post
                              Last post
                            0
                            • Categories
                            • Recent
                            • Tags
                            • Popular
                            • Users
                            • Groups
                            • Search
                            • Get Qt Extensions
                            • Unsolved