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Read a file txt

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  • mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by mrjj
    #8

    Hi
    ok that i cant explain.

    Best guess is that you read data from a serial port and call save and load
    pr DataReady signal and hence we see it like this.

    When reading from serial port, all data might not come in one go. And it kinda looks like this but
    I can't understand how your text file then looks normal.
    (ahh you use append so the end result looks normal )

    can you show the code around where you call updateGUI_sonde ?

    L 1 Reply Last reply
    1
    • J.HilkJ Offline
      J.HilkJ Offline
      J.Hilk
      Moderators
      wrote on last edited by
      #9

      @LatitudeFr I still think, there's a loop, or at least multiple calls to updateGUI_sonde

      add a debug() statement there, to test that

      void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
          qDebug() << Q_FUNC_INFO << data_sonde.toHex(' '); // <------ this one
          //ecrire les données***********************
          QFile file("data_sonde.txt");
          QStringList line_data ;
      
          if( file.open(QIODevice::Append)) {
             QTextStream data(&file);
             data<<data_sonde;
      
             file.close();
      
      //lire les données*************************
             QStringList line ;
             if (!file.open(QFile::ReadOnly | QFile::Text)) {
                    qDebug()<<"File not exists";
             } else {
                  QTextStream lire_data(&file);
                  while (!lire_data.atEnd()) {
                          qDebug() << lire_data.readLine();
                  }
                  file.close();
            }
         }
      }
      

      Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


      Q: What's that?
      A: It's blue light.
      Q: What does it do?
      A: It turns blue.

      L 1 Reply Last reply
      1
      • L LatitudeFr

        @mrjj the code :
        void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
        //ecrire les données***********************
        QFile file("data_sonde.txt");
        QStringList line_data ;

        if( file.open(QIODevice::Append)) {
        
            QTextStream data(&file);
            data<<data_sonde;
        
        
           file.close();
        

        //lire les données*************************
        QStringList line ;
        if (!file.open(QFile::ReadOnly | QFile::Text)){
        qDebug()<<"File not exists";
        }
        else {
        QTextStream lire_data(&file);
        while (!lire_data.atEnd())
        {

          qDebug() << lire_data.readLine();
          }
        

        file.close();

               }
        }
        

        }

        result :

        275c355e-42f9-4ff0-96f5-c0c7bf392f97-image.png

        file txt :

        935fb7c9-1553-4128-b14b-a675aa1c28e1-image.png

        M Offline
        M Offline
        mpergand
        wrote on last edited by
        #10

        @LatitudeFr
        Salut,
        Utilise les chevrons <> pour rendre le code plus lisible.

        void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
        //ecrire les données***********************
        QFile file("data_sonde.txt");
        QStringList line_data ;
        
        if( file.open(QIODevice::Append)) {
        
            QTextStream data(&file);
            data<<data_sonde;
        

        You add/append data over again each time you execute your prog .

        1 Reply Last reply
        0
        • J.HilkJ J.Hilk

          @LatitudeFr I still think, there's a loop, or at least multiple calls to updateGUI_sonde

          add a debug() statement there, to test that

          void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
              qDebug() << Q_FUNC_INFO << data_sonde.toHex(' '); // <------ this one
              //ecrire les données***********************
              QFile file("data_sonde.txt");
              QStringList line_data ;
          
              if( file.open(QIODevice::Append)) {
                 QTextStream data(&file);
                 data<<data_sonde;
          
                 file.close();
          
          //lire les données*************************
                 QStringList line ;
                 if (!file.open(QFile::ReadOnly | QFile::Text)) {
                        qDebug()<<"File not exists";
                 } else {
                      QTextStream lire_data(&file);
                      while (!lire_data.atEnd()) {
                              qDebug() << lire_data.readLine();
                      }
                      file.close();
                }
             }
          }
          
          L Offline
          L Offline
          LatitudeFr
          wrote on last edited by
          #11

          @J-Hilk thank you for your reply
          the result :
          a05a7025-381d-4b2b-b155-222b7a1c82b8-image.png
          can i send you the code by e-mail ?

          J.HilkJ 1 Reply Last reply
          0
          • mrjjM mrjj

            Hi
            ok that i cant explain.

            Best guess is that you read data from a serial port and call save and load
            pr DataReady signal and hence we see it like this.

            When reading from serial port, all data might not come in one go. And it kinda looks like this but
            I can't understand how your text file then looks normal.
            (ahh you use append so the end result looks normal )

            can you show the code around where you call updateGUI_sonde ?

            L Offline
            L Offline
            LatitudeFr
            wrote on last edited by
            #12

            @mrjj the code :

            connect(_sonde, &sonde::gotNewData_sonde, this, &MainWindow::updateGUI_sonde);
            

            signals:
            void gotNewData_sonde(QByteArray data_sonde );//prototype du signal
            void sonde::newData_sonde() {

            emit gotNewData_sonde(_sonde.readAll()); // lire tout les donnes dans le port serie
            

            }

            1 Reply Last reply
            1
            • L LatitudeFr

              @J-Hilk thank you for your reply
              the result :
              a05a7025-381d-4b2b-b155-222b7a1c82b8-image.png
              can i send you the code by e-mail ?

              J.HilkJ Offline
              J.HilkJ Offline
              J.Hilk
              Moderators
              wrote on last edited by
              #13

              @LatitudeFr no need, you need to accumulate your data.

              like @mrjj said, your serial port(?) doesn't notify you when all data arrived, it does when any data arrived.

              and you have to store that and decide when and how all data arrived.

              from what you showed, I would say your message ends with a 0x2320aka # and space.

              QByteArray accumulatedData; 
              QByteArray expectedEnd=  QByteArray::fromHex("2320");
              void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
                  qDebug() << Q_FUNC_INFO << data_sonde.toHex(' '); // <------ this one
                  accumulatedData.append(data_sonde);
               
                  if(!accumulatedData.endsWith(expectedEnd))
                     return;
                  //ecrire les données***********************
                  QFile file("data_sonde.txt");
                  QStringList line_data ;
              
                  if( file.open(QIODevice::Append)) {
                     QTextStream data(&file);
                     data<<accumulatedData;
              
                     file.close();
                     accumulatedData.clear();
              
              //lire les données*************************
                     QStringList line ;
                     if (!file.open(QFile::ReadOnly | QFile::Text)) {
                            qDebug()<<"File not exists";
                     } else {
                          QTextStream lire_data(&file);
                          while (!lire_data.atEnd()) {
                                  qDebug() << lire_data.readLine();
                          }
                          file.close();
                    }
                 }
              }
              

              Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


              Q: What's that?
              A: It's blue light.
              Q: What does it do?
              A: It turns blue.

              L 1 Reply Last reply
              2
              • J.HilkJ J.Hilk

                @LatitudeFr no need, you need to accumulate your data.

                like @mrjj said, your serial port(?) doesn't notify you when all data arrived, it does when any data arrived.

                and you have to store that and decide when and how all data arrived.

                from what you showed, I would say your message ends with a 0x2320aka # and space.

                QByteArray accumulatedData; 
                QByteArray expectedEnd=  QByteArray::fromHex("2320");
                void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
                    qDebug() << Q_FUNC_INFO << data_sonde.toHex(' '); // <------ this one
                    accumulatedData.append(data_sonde);
                 
                    if(!accumulatedData.endsWith(expectedEnd))
                       return;
                    //ecrire les données***********************
                    QFile file("data_sonde.txt");
                    QStringList line_data ;
                
                    if( file.open(QIODevice::Append)) {
                       QTextStream data(&file);
                       data<<accumulatedData;
                
                       file.close();
                       accumulatedData.clear();
                
                //lire les données*************************
                       QStringList line ;
                       if (!file.open(QFile::ReadOnly | QFile::Text)) {
                              qDebug()<<"File not exists";
                       } else {
                            QTextStream lire_data(&file);
                            while (!lire_data.atEnd()) {
                                    qDebug() << lire_data.readLine();
                            }
                            file.close();
                      }
                   }
                }
                
                L Offline
                L Offline
                LatitudeFr
                wrote on last edited by
                #14

                @J-Hilk it works very well thank you very much but please how I can read just the last line

                mrjjM 1 Reply Last reply
                0
                • L LatitudeFr

                  @J-Hilk it works very well thank you very much but please how I can read just the last line

                  mrjjM Offline
                  mrjjM Offline
                  mrjj
                  Lifetime Qt Champion
                  wrote on last edited by mrjj
                  #15

                  @LatitudeFr

                  Hi
                  it doesn't work like that :)

                  Say you send "This is my line" from the board.

                  then you get more than one read signal and data comes like

                  Thi
                  is m
                  y li
                  ne

                  so you need to add them together to make a line of it.
                  In this case we know we got all data when we see #

                  there is no last line. it comes in bytes and we make a line from that.

                  L 1 Reply Last reply
                  2
                  • mrjjM mrjj

                    @LatitudeFr

                    Hi
                    it doesn't work like that :)

                    Say you send "This is my line" from the board.

                    then you get more than one read signal and data comes like

                    Thi
                    is m
                    y li
                    ne

                    so you need to add them together to make a line of it.
                    In this case we know we got all data when we see #

                    there is no last line. it comes in bytes and we make a line from that.

                    L Offline
                    L Offline
                    LatitudeFr
                    wrote on last edited by
                    #16

                    @mrjj with this code the problem is solved but I would need to read every time I press the button just the last line and not all the lines
                    the code :
                    QByteArray accumulatedData;
                    QByteArray expectedEnd= QByteArray::fromHex("2320");
                    void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
                    // qDebug() << Q_FUNC_INFO << data_sonde.toHex(' '); // <------ this one
                    accumulatedData.append(data_sonde);

                    if(!accumulatedData.endsWith(expectedEnd))
                       return;
                    
                    //ecrire les données***********************
                    QFile file("data_sonde.txt");
                    QStringList line_data ;
                    
                    if( file.open(QIODevice::Append)) {
                       QTextStream data(&file);
                       data<<accumulatedData;
                    
                       file.close();
                       accumulatedData.clear();
                    

                    //lire les données*************************
                    QStringList line ;
                    if (!file.open(QFile::ReadOnly | QFile::Text)) {
                    qDebug()<<"File not exists";
                    } else {
                    QTextStream lire_data(&file);
                    while (!lire_data.atEnd()) {
                    line =lire_data.readLine().split(' ');
                    if(!line.contains(("para")))
                    {
                    if(!line.contains(("data")))
                    {
                    if(!line.contains(("#")))
                    {

                                               bool ok;
                                               float ph =line.at(0).toDouble(&ok);
                                               if(!ok)
                                               continue;
                                               qDebug()<<ph;
                                               ui->sonde_label->setNum(ph);
                    
                                     qDebug() << line;
                                           }
                                    }
                                }
                            }
                            file.close();
                      }
                    

                    }
                    }

                    the file.txt
                    875033b3-1f5a-47f4-af8a-1028e228595a-image.png

                    the result
                    6394b266-46f8-4a2a-a90d-520e91c30737-image.png

                    1 Reply Last reply
                    0
                    • mrjjM Offline
                      mrjjM Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on last edited by
                      #17

                      Hi
                      Since you now wait until you see #

                      if(!accumulatedData.endsWith(expectedEnd))
                         return;
                      

                      then you might want to use

                      file.open(QIODevice::Read | QIODevice::Truncate | QIODevice::Text);
                      and not
                      file.open(QIODevice::Append)

                      so you only save the complete line once. Else if you test more than once and don't delete the file between,
                      it will have more than 1 data line /set. Like you show in the notepad image.

                      L 1 Reply Last reply
                      0
                      • mrjjM mrjj

                        Hi
                        Since you now wait until you see #

                        if(!accumulatedData.endsWith(expectedEnd))
                           return;
                        

                        then you might want to use

                        file.open(QIODevice::Read | QIODevice::Truncate | QIODevice::Text);
                        and not
                        file.open(QIODevice::Append)

                        so you only save the complete line once. Else if you test more than once and don't delete the file between,
                        it will have more than 1 data line /set. Like you show in the notepad image.

                        L Offline
                        L Offline
                        LatitudeFr
                        wrote on last edited by LatitudeFr
                        #18

                        @mrjj thank your for your reply but i need file.open(QIODevice::Append) to write on the file
                        for the first time it reads only one data since in our file there is only one data but when I press the button for the second time it reads 2 data since we have 2 data in the file but I would need to read just the last data

                        for the first time
                        1.PNG
                        2.PNG

                        for the second time
                        3.PNG
                        4.PNG

                        mrjjM 1 Reply Last reply
                        0
                        • L LatitudeFr

                          @mrjj thank your for your reply but i need file.open(QIODevice::Append) to write on the file
                          for the first time it reads only one data since in our file there is only one data but when I press the button for the second time it reads 2 data since we have 2 data in the file but I would need to read just the last data

                          for the first time
                          1.PNG
                          2.PNG

                          for the second time
                          3.PNG
                          4.PNG

                          mrjjM Offline
                          mrjjM Offline
                          mrjj
                          Lifetime Qt Champion
                          wrote on last edited by mrjj
                          #19

                          @LatitudeFr

                          Why ?

                          it will only write a full line since we wait until we see #

                          so when your load part runs, then it can load the full line.

                          Using append when opening the files allows appending more to it next time.
                          but unless board sent many different data lines and you only want the last one, I'm not sure why
                          you need append ?

                          (update) Ahh. you do want to send more than one data line and store all in a file but then later
                          only use the last data ?

                          1 Reply Last reply
                          0
                          • J.HilkJ Offline
                            J.HilkJ Offline
                            J.Hilk
                            Moderators
                            wrote on last edited by
                            #20
                            QByteArray accumulatedData; 
                            QByteArray expectedEnd=  QByteArray::fromHex("2320");
                            void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
                                qDebug() << Q_FUNC_INFO << data_sonde.toHex(' '); // <------ this one
                                accumulatedData.append(data_sonde);
                             
                                if(!accumulatedData.endsWith(expectedEnd))
                                   return;
                                //ecrire les données***********************
                                QFile file("data_sonde.txt");
                                QStringList line_data ;
                            
                                if( file.open(QIODevice::Append)) {
                                   QTextStream data(&file);
                                   data<<accumulatedData;
                            
                                   file.close();
                                   
                            //lire les données*************************
                                   QStringList line ;
                                   if (!file.open(QFile::ReadOnly | QFile::Text)) {
                                          qDebug()<<"File not exists";
                                   } else {
                                        QTextStream lire_data(&file);
                                        lire_data.seek(file.size() - accumulatedData.size());
                                        while (!lire_data.atEnd()) {
                                                qDebug() << lire_data.readLine();
                                        }
                                        file.close();
                                  }
                               }
                               accumulatedData.clear(); //We now clear at the very end
                            }
                            

                            Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                            Q: What's that?
                            A: It's blue light.
                            Q: What does it do?
                            A: It turns blue.

                            mrjjM 1 Reply Last reply
                            2
                            • J.HilkJ J.Hilk
                              QByteArray accumulatedData; 
                              QByteArray expectedEnd=  QByteArray::fromHex("2320");
                              void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
                                  qDebug() << Q_FUNC_INFO << data_sonde.toHex(' '); // <------ this one
                                  accumulatedData.append(data_sonde);
                               
                                  if(!accumulatedData.endsWith(expectedEnd))
                                     return;
                                  //ecrire les données***********************
                                  QFile file("data_sonde.txt");
                                  QStringList line_data ;
                              
                                  if( file.open(QIODevice::Append)) {
                                     QTextStream data(&file);
                                     data<<accumulatedData;
                              
                                     file.close();
                                     
                              //lire les données*************************
                                     QStringList line ;
                                     if (!file.open(QFile::ReadOnly | QFile::Text)) {
                                            qDebug()<<"File not exists";
                                     } else {
                                          QTextStream lire_data(&file);
                                          lire_data.seek(file.size() - accumulatedData.size());
                                          while (!lire_data.atEnd()) {
                                                  qDebug() << lire_data.readLine();
                                          }
                                          file.close();
                                    }
                                 }
                                 accumulatedData.clear(); //We now clear at the very end
                              }
                              
                              mrjjM Offline
                              mrjjM Offline
                              mrjj
                              Lifetime Qt Champion
                              wrote on last edited by
                              #21

                              @J-Hilk
                              Cool but wont he just get the last # and not the data line ?

                              J.HilkJ 1 Reply Last reply
                              0
                              • mrjjM mrjj

                                @J-Hilk
                                Cool but wont he just get the last # and not the data line ?

                                J.HilkJ Offline
                                J.HilkJ Offline
                                J.Hilk
                                Moderators
                                wrote on last edited by
                                #22

                                @mrjj he shouldn't, wee accumulate the whole message, before we actually write:

                                void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
                                    qDebug() << Q_FUNC_INFO << data_sonde.toHex(' '); // <------ this one
                                    accumulatedData.append(data_sonde);
                                 
                                    if(!accumulatedData.endsWith(expectedEnd))
                                       return;
                                

                                Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                                Q: What's that?
                                A: It's blue light.
                                Q: What does it do?
                                A: It turns blue.

                                L 1 Reply Last reply
                                2
                                • J.HilkJ J.Hilk

                                  @mrjj he shouldn't, wee accumulate the whole message, before we actually write:

                                  void MainWindow::updateGUI_sonde(QByteArray data_sonde) {
                                      qDebug() << Q_FUNC_INFO << data_sonde.toHex(' '); // <------ this one
                                      accumulatedData.append(data_sonde);
                                   
                                      if(!accumulatedData.endsWith(expectedEnd))
                                         return;
                                  
                                  L Offline
                                  L Offline
                                  LatitudeFr
                                  wrote on last edited by
                                  #23

                                  @J-Hilk @mrjj thank you it works very well

                                  1 Reply Last reply
                                  0

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