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How to save a table in a file

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  • D Daesos

    Hello. I'm new here, but i've already read many topic of this forum.
    I'm creating a program that monitors a directory.
    I've searched for a method to save a tablewidget to a file and this is what I've made:

    void MainWindow::on_pushButton_2_clicked()
    {
    QFile csv("log_activity.csv");
    
    if(!csv.open(QFile::WriteOnly))
        return;
    
    QTextStream out(&csv);
    
    for(int i = 0; i < ui->tableWidget->rowCount(); ++i)
        for (int j = 1; j < ui->tableWidget->columnCount(); j++)
            out<<ui->tableWidget->item(i, j)->text();
    
    csv.close();
    }
    

    This is my tablewidget:

    0_1531208468134_7dddbc22-3ed3-431d-99d3-0f05a3a3dc79-image.png

    The problem is that once i click on the save button (pushButton_2) the program doesn't save anything in the file. What am i missing?

    jsulmJ Offline
    jsulmJ Offline
    jsulm
    Lifetime Qt Champion
    wrote on last edited by
    #4

    @Daesos Are you sure it does not save the file? You're using a relative path, that means the file will be located in the current working directory of your app, most probably in the build directory. Also did you check whether MainWindow::on_pushButton_2_clicked() was actually called?

    https://forum.qt.io/topic/113070/qt-code-of-conduct

    1 Reply Last reply
    1
    • D Offline
      D Offline
      Daesos
      wrote on last edited by Daesos
      #5

      The image above is the directory of my project. If I click on save button, the cell corresponding to log_activity.csv and Event changes into modified.
      It shows "Modified" when the date of the previous directory is different from the current one.
      So I guess the save_button works.

      0_1531210402194_729a0dca-9bc9-4745-a532-9d41af2aef78-image.png

      Also, if the file doesn't exit, the program create the file with the given name.

      jsulmJ JonBJ 2 Replies Last reply
      0
      • D Daesos

        I'd like to not implement other libraries. I want to resolve this only with given libraries by Qt.

        VRoninV Offline
        VRoninV Offline
        VRonin
        wrote on last edited by VRonin
        #6

        @Daesos said in How to save a table in a file:

        I want to resolve this only with given libraries by Qt

        Then copy-paste my code. I only use Qt in those and license is apache 2 so you can basically do what you want with it.

        In your code above you are not:

        • Writing any new line to separate rows.
        • Writing any column separator
        • Escaping column separators inside the data

        "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
        ~Napoleon Bonaparte

        On a crusade to banish setIndexWidget() from the holy land of Qt

        1 Reply Last reply
        0
        • D Daesos

          The image above is the directory of my project. If I click on save button, the cell corresponding to log_activity.csv and Event changes into modified.
          It shows "Modified" when the date of the previous directory is different from the current one.
          So I guess the save_button works.

          0_1531210402194_729a0dca-9bc9-4745-a532-9d41af2aef78-image.png

          Also, if the file doesn't exit, the program create the file with the given name.

          jsulmJ Offline
          jsulmJ Offline
          jsulm
          Lifetime Qt Champion
          wrote on last edited by
          #7

          @Daesos Did you try to debug? Especially the nested for loops?

          https://forum.qt.io/topic/113070/qt-code-of-conduct

          D 1 Reply Last reply
          0
          • D Daesos

            The image above is the directory of my project. If I click on save button, the cell corresponding to log_activity.csv and Event changes into modified.
            It shows "Modified" when the date of the previous directory is different from the current one.
            So I guess the save_button works.

            0_1531210402194_729a0dca-9bc9-4745-a532-9d41af2aef78-image.png

            Also, if the file doesn't exit, the program create the file with the given name.

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

            @Daesos
            Assuming the file is opened for write, you are saying you end up with nothing in it, and your table does indeed contain desired text (ui->tableWidget->item(i, j)->text()). You stream all your data to QTextStream out but you only close the QFile csv. I don't know if that knows to fetch all remaining data out of the stream. Try out.flush() prior to the csv.close()?

            1 Reply Last reply
            1
            • jsulmJ jsulm

              @Daesos Did you try to debug? Especially the nested for loops?

              D Offline
              D Offline
              Daesos
              wrote on last edited by Daesos
              #9

              @jsulm I'm trying, but it stops with this message: Stopped "end-stepping-range". I've put a breakpoint at "out<<ui->tableWidget->item(i, j)->text();" and as i can see, this returns "main.window.cpp", which is correct. Then, I don't what happen.

              jsulmJ 1 Reply Last reply
              0
              • D Daesos

                @jsulm I'm trying, but it stops with this message: Stopped "end-stepping-range". I've put a breakpoint at "out<<ui->tableWidget->item(i, j)->text();" and as i can see, this returns "main.window.cpp", which is correct. Then, I don't what happen.

                jsulmJ Offline
                jsulmJ Offline
                jsulm
                Lifetime Qt Champion
                wrote on last edited by
                #10

                @Daesos Try calling http://doc.qt.io/qt-5/qtextstream.html#flush before closing the file

                https://forum.qt.io/topic/113070/qt-code-of-conduct

                D 1 Reply Last reply
                0
                • jsulmJ jsulm

                  @Daesos Try calling http://doc.qt.io/qt-5/qtextstream.html#flush before closing the file

                  D Offline
                  D Offline
                  Daesos
                  wrote on last edited by
                  #11

                  @jsulm Already did, and nothing changed.

                  jsulmJ 1 Reply Last reply
                  0
                  • D Daesos

                    @jsulm Already did, and nothing changed.

                    jsulmJ Offline
                    jsulmJ Offline
                    jsulm
                    Lifetime Qt Champion
                    wrote on last edited by
                    #12

                    @Daesos Last idea I have: is it possible that you open same file somewhere else in your app, or that there is still an instance of your app running?
                    Oh, one more idea: try to write the file using an absolute path to some other location.

                    https://forum.qt.io/topic/113070/qt-code-of-conduct

                    D 1 Reply Last reply
                    0
                    • jsulmJ jsulm

                      @Daesos Last idea I have: is it possible that you open same file somewhere else in your app, or that there is still an instance of your app running?
                      Oh, one more idea: try to write the file using an absolute path to some other location.

                      D Offline
                      D Offline
                      Daesos
                      wrote on last edited by Daesos
                      #13

                      @jsulm I checked and there is no other instance opened. Also, I used another path. The program created the file.csv (empty), then quitted. Application Output: "The program has unexpectedly finished."

                      Since I don't know if I have mistaken something I will post all the mainwindow.cpp code:

                      #include "mainwindow.h"
                      #include "ui_mainwindow.h"
                      #include <QFileDialog>
                      #include <QFileInfo>
                      #include <QTimer>
                      #include <QDateTime>
                      #include <QFile>
                      #include <QTextStream>
                      
                      MainWindow::MainWindow(QWidget *parent) :
                          QMainWindow(parent),
                          ui(new Ui::MainWindow)
                      {
                          ui->setupUi(this);
                      
                          setWindowTitle("DirectoryMonitor");
                          ui->tableWidget->setColumnCount(4);
                          ui->tableWidget->setHorizontalHeaderLabels(QStringList() << "" << "Filename" << "Event" << "Time");
                      
                          f_name = "log_activity.csv";
                      }
                      
                      MainWindow::~MainWindow()
                      {
                          delete ui;
                      }
                      
                      void MainWindow::on_pushButton_clicked()
                      {
                          ui->tableWidget->clearContents();
                          path = QFileDialog::getExistingDirectory(this, tr("Open Directory"), ".", QFileDialog::ShowDirsOnly | QFileDialog::DontResolveSymlinks);
                          ui->lineEdit->setText(path);
                      
                      QDir dir(path);
                      
                      dir.setFilter(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot);
                      dir.setSorting(QDir::Time);
                      list = dir.entryInfoList();
                      
                      for(int i = 0; i < list.size(); ++i){
                              ui->tableWidget->insertRow(ui->tableWidget->rowCount());
                              ui->tableWidget->setItem(i, 1, new QTableWidgetItem(list.at(i).fileName()));
                              ui->tableWidget->setItem(i, 3, new QTableWidgetItem(list.at(i).lastModified().toString()));
                      }
                      
                      int count = 0;
                      
                      for(int i = 0; i < ui->tableWidget->rowCount(); ++i){
                          QTableWidgetItem *itm = ui->tableWidget->item(i, 1);
                          if(itm != 0)
                             ++count;
                      }
                      //rimuovi righe vuote
                      ui->tableWidget->setRowCount(count);
                      
                      QTimer *time = new QTimer(this);
                      
                      connect(time, SIGNAL(timeout()), this, SLOT(changes()));
                      time->start(3000);
                      }
                      
                      void MainWindow::changes()
                      {
                      QDir dir(path);
                      dir.setFilter(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot);
                      dir.setSorting(QDir::Time);
                      
                      QFileInfoList newlist = dir.entryInfoList();
                      
                      int index_delete = -1;
                      
                      //caso modified e delete file
                      for(int i = 0; i < list.size(); ++i){
                          int count = 0;
                          for(int j = 0; j < newlist.size(); ++j){
                              if(list.at(i).fileName() == newlist.at(j).fileName()){
                                  ++count;
                                  if(list.at(i).lastModified() != newlist.at(j).lastModified()){
                                      QTableWidgetItem *itm = new QTableWidgetItem("");
                                      itm->setBackground(QColor(109, 158, 235));
                                      ui->tableWidget->setItem(i, 0, itm);
                                      ui->tableWidget->setItem(i, 2, new QTableWidgetItem("Modified"));
                                      ui->tableWidget->setItem(i, 3, new QTableWidgetItem(newlist.at(j).lastModified().toString()));
                                  }
                              }
                          }
                          if(count == 0){
                              index_delete = i;
                          }
                      }
                      
                      if(index_delete != -1){
                          QTableWidgetItem *itm = new QTableWidgetItem("");
                          itm->setBackground(QColor(224, 102, 99));
                          ui->tableWidget->setItem(index_delete, 0, itm);
                          if(ui->tableWidget->item(index_delete, 2)->text() != "Deleted")
                              ui->tableWidget->setItem(index_delete, 3, new QTableWidgetItem(QDateTime::currentDateTime().toString()));
                          ui->tableWidget->setItem(index_delete, 2, new QTableWidgetItem("Deleted"));
                      }
                      
                      //caso new file
                      int index_new = -1;
                      
                      for(int i = 0; i < newlist.size(); ++i){
                          int count = 0;
                          for(int j = 0; (j < list.size() && count == 0); ++j){
                              if(newlist.at(i).fileName() == list.at(j).fileName())
                                  ++count;
                          }
                          if(count == 0)
                              index_new = i;
                      }
                      
                      if(index_new != -1){
                          ui->tableWidget->insertRow(ui->tableWidget->rowCount());
                          QTableWidgetItem *itm = new QTableWidgetItem("");
                          itm->setBackground(QColor(148, 195, 123));
                          ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 0, itm);
                          ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 1, new QTableWidgetItem(newlist.at(index_new).fileName()));
                          ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 2, new QTableWidgetItem("Created"));
                          ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 3, new QTableWidgetItem(newlist.at(index_new).lastModified().toString()));
                          list.append(newlist.at(index_new));
                      }
                      }
                      void MainWindow::on_pushButton_2_clicked()
                      {
                      QFile csv(f_name);
                      
                      if(!csv.open(QFile::WriteOnly))
                          return;
                      
                      QTextStream out(&csv);
                      
                      for(int i = 0; i < ui->tableWidget->rowCount(); ++i)
                          for (int j = 1; j < ui->tableWidget->columnCount(); j++){
                              QString txt(ui->tableWidget->item(i, j)->text());
                              out<<txt;
                          }
                      out.flush();
                      csv.close();
                      }
                      

                      Sorry for the indentation.
                      This is the declaration of the global variables in mainwindow.h

                      QString path, f_name;
                      QFileInfoList list;
                      
                      jsulmJ J.HilkJ JonBJ 3 Replies Last reply
                      0
                      • D Daesos

                        @jsulm I checked and there is no other instance opened. Also, I used another path. The program created the file.csv (empty), then quitted. Application Output: "The program has unexpectedly finished."

                        Since I don't know if I have mistaken something I will post all the mainwindow.cpp code:

                        #include "mainwindow.h"
                        #include "ui_mainwindow.h"
                        #include <QFileDialog>
                        #include <QFileInfo>
                        #include <QTimer>
                        #include <QDateTime>
                        #include <QFile>
                        #include <QTextStream>
                        
                        MainWindow::MainWindow(QWidget *parent) :
                            QMainWindow(parent),
                            ui(new Ui::MainWindow)
                        {
                            ui->setupUi(this);
                        
                            setWindowTitle("DirectoryMonitor");
                            ui->tableWidget->setColumnCount(4);
                            ui->tableWidget->setHorizontalHeaderLabels(QStringList() << "" << "Filename" << "Event" << "Time");
                        
                            f_name = "log_activity.csv";
                        }
                        
                        MainWindow::~MainWindow()
                        {
                            delete ui;
                        }
                        
                        void MainWindow::on_pushButton_clicked()
                        {
                            ui->tableWidget->clearContents();
                            path = QFileDialog::getExistingDirectory(this, tr("Open Directory"), ".", QFileDialog::ShowDirsOnly | QFileDialog::DontResolveSymlinks);
                            ui->lineEdit->setText(path);
                        
                        QDir dir(path);
                        
                        dir.setFilter(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot);
                        dir.setSorting(QDir::Time);
                        list = dir.entryInfoList();
                        
                        for(int i = 0; i < list.size(); ++i){
                                ui->tableWidget->insertRow(ui->tableWidget->rowCount());
                                ui->tableWidget->setItem(i, 1, new QTableWidgetItem(list.at(i).fileName()));
                                ui->tableWidget->setItem(i, 3, new QTableWidgetItem(list.at(i).lastModified().toString()));
                        }
                        
                        int count = 0;
                        
                        for(int i = 0; i < ui->tableWidget->rowCount(); ++i){
                            QTableWidgetItem *itm = ui->tableWidget->item(i, 1);
                            if(itm != 0)
                               ++count;
                        }
                        //rimuovi righe vuote
                        ui->tableWidget->setRowCount(count);
                        
                        QTimer *time = new QTimer(this);
                        
                        connect(time, SIGNAL(timeout()), this, SLOT(changes()));
                        time->start(3000);
                        }
                        
                        void MainWindow::changes()
                        {
                        QDir dir(path);
                        dir.setFilter(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot);
                        dir.setSorting(QDir::Time);
                        
                        QFileInfoList newlist = dir.entryInfoList();
                        
                        int index_delete = -1;
                        
                        //caso modified e delete file
                        for(int i = 0; i < list.size(); ++i){
                            int count = 0;
                            for(int j = 0; j < newlist.size(); ++j){
                                if(list.at(i).fileName() == newlist.at(j).fileName()){
                                    ++count;
                                    if(list.at(i).lastModified() != newlist.at(j).lastModified()){
                                        QTableWidgetItem *itm = new QTableWidgetItem("");
                                        itm->setBackground(QColor(109, 158, 235));
                                        ui->tableWidget->setItem(i, 0, itm);
                                        ui->tableWidget->setItem(i, 2, new QTableWidgetItem("Modified"));
                                        ui->tableWidget->setItem(i, 3, new QTableWidgetItem(newlist.at(j).lastModified().toString()));
                                    }
                                }
                            }
                            if(count == 0){
                                index_delete = i;
                            }
                        }
                        
                        if(index_delete != -1){
                            QTableWidgetItem *itm = new QTableWidgetItem("");
                            itm->setBackground(QColor(224, 102, 99));
                            ui->tableWidget->setItem(index_delete, 0, itm);
                            if(ui->tableWidget->item(index_delete, 2)->text() != "Deleted")
                                ui->tableWidget->setItem(index_delete, 3, new QTableWidgetItem(QDateTime::currentDateTime().toString()));
                            ui->tableWidget->setItem(index_delete, 2, new QTableWidgetItem("Deleted"));
                        }
                        
                        //caso new file
                        int index_new = -1;
                        
                        for(int i = 0; i < newlist.size(); ++i){
                            int count = 0;
                            for(int j = 0; (j < list.size() && count == 0); ++j){
                                if(newlist.at(i).fileName() == list.at(j).fileName())
                                    ++count;
                            }
                            if(count == 0)
                                index_new = i;
                        }
                        
                        if(index_new != -1){
                            ui->tableWidget->insertRow(ui->tableWidget->rowCount());
                            QTableWidgetItem *itm = new QTableWidgetItem("");
                            itm->setBackground(QColor(148, 195, 123));
                            ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 0, itm);
                            ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 1, new QTableWidgetItem(newlist.at(index_new).fileName()));
                            ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 2, new QTableWidgetItem("Created"));
                            ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 3, new QTableWidgetItem(newlist.at(index_new).lastModified().toString()));
                            list.append(newlist.at(index_new));
                        }
                        }
                        void MainWindow::on_pushButton_2_clicked()
                        {
                        QFile csv(f_name);
                        
                        if(!csv.open(QFile::WriteOnly))
                            return;
                        
                        QTextStream out(&csv);
                        
                        for(int i = 0; i < ui->tableWidget->rowCount(); ++i)
                            for (int j = 1; j < ui->tableWidget->columnCount(); j++){
                                QString txt(ui->tableWidget->item(i, j)->text());
                                out<<txt;
                            }
                        out.flush();
                        csv.close();
                        }
                        

                        Sorry for the indentation.
                        This is the declaration of the global variables in mainwindow.h

                        QString path, f_name;
                        QFileInfoList list;
                        
                        jsulmJ Offline
                        jsulmJ Offline
                        jsulm
                        Lifetime Qt Champion
                        wrote on last edited by
                        #14

                        @Daesos Start your app with debugger (F5) and when it crashes check the stack trace to see where it crashes (use debug build of your app).

                        https://forum.qt.io/topic/113070/qt-code-of-conduct

                        1 Reply Last reply
                        0
                        • D Daesos

                          @jsulm I checked and there is no other instance opened. Also, I used another path. The program created the file.csv (empty), then quitted. Application Output: "The program has unexpectedly finished."

                          Since I don't know if I have mistaken something I will post all the mainwindow.cpp code:

                          #include "mainwindow.h"
                          #include "ui_mainwindow.h"
                          #include <QFileDialog>
                          #include <QFileInfo>
                          #include <QTimer>
                          #include <QDateTime>
                          #include <QFile>
                          #include <QTextStream>
                          
                          MainWindow::MainWindow(QWidget *parent) :
                              QMainWindow(parent),
                              ui(new Ui::MainWindow)
                          {
                              ui->setupUi(this);
                          
                              setWindowTitle("DirectoryMonitor");
                              ui->tableWidget->setColumnCount(4);
                              ui->tableWidget->setHorizontalHeaderLabels(QStringList() << "" << "Filename" << "Event" << "Time");
                          
                              f_name = "log_activity.csv";
                          }
                          
                          MainWindow::~MainWindow()
                          {
                              delete ui;
                          }
                          
                          void MainWindow::on_pushButton_clicked()
                          {
                              ui->tableWidget->clearContents();
                              path = QFileDialog::getExistingDirectory(this, tr("Open Directory"), ".", QFileDialog::ShowDirsOnly | QFileDialog::DontResolveSymlinks);
                              ui->lineEdit->setText(path);
                          
                          QDir dir(path);
                          
                          dir.setFilter(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot);
                          dir.setSorting(QDir::Time);
                          list = dir.entryInfoList();
                          
                          for(int i = 0; i < list.size(); ++i){
                                  ui->tableWidget->insertRow(ui->tableWidget->rowCount());
                                  ui->tableWidget->setItem(i, 1, new QTableWidgetItem(list.at(i).fileName()));
                                  ui->tableWidget->setItem(i, 3, new QTableWidgetItem(list.at(i).lastModified().toString()));
                          }
                          
                          int count = 0;
                          
                          for(int i = 0; i < ui->tableWidget->rowCount(); ++i){
                              QTableWidgetItem *itm = ui->tableWidget->item(i, 1);
                              if(itm != 0)
                                 ++count;
                          }
                          //rimuovi righe vuote
                          ui->tableWidget->setRowCount(count);
                          
                          QTimer *time = new QTimer(this);
                          
                          connect(time, SIGNAL(timeout()), this, SLOT(changes()));
                          time->start(3000);
                          }
                          
                          void MainWindow::changes()
                          {
                          QDir dir(path);
                          dir.setFilter(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot);
                          dir.setSorting(QDir::Time);
                          
                          QFileInfoList newlist = dir.entryInfoList();
                          
                          int index_delete = -1;
                          
                          //caso modified e delete file
                          for(int i = 0; i < list.size(); ++i){
                              int count = 0;
                              for(int j = 0; j < newlist.size(); ++j){
                                  if(list.at(i).fileName() == newlist.at(j).fileName()){
                                      ++count;
                                      if(list.at(i).lastModified() != newlist.at(j).lastModified()){
                                          QTableWidgetItem *itm = new QTableWidgetItem("");
                                          itm->setBackground(QColor(109, 158, 235));
                                          ui->tableWidget->setItem(i, 0, itm);
                                          ui->tableWidget->setItem(i, 2, new QTableWidgetItem("Modified"));
                                          ui->tableWidget->setItem(i, 3, new QTableWidgetItem(newlist.at(j).lastModified().toString()));
                                      }
                                  }
                              }
                              if(count == 0){
                                  index_delete = i;
                              }
                          }
                          
                          if(index_delete != -1){
                              QTableWidgetItem *itm = new QTableWidgetItem("");
                              itm->setBackground(QColor(224, 102, 99));
                              ui->tableWidget->setItem(index_delete, 0, itm);
                              if(ui->tableWidget->item(index_delete, 2)->text() != "Deleted")
                                  ui->tableWidget->setItem(index_delete, 3, new QTableWidgetItem(QDateTime::currentDateTime().toString()));
                              ui->tableWidget->setItem(index_delete, 2, new QTableWidgetItem("Deleted"));
                          }
                          
                          //caso new file
                          int index_new = -1;
                          
                          for(int i = 0; i < newlist.size(); ++i){
                              int count = 0;
                              for(int j = 0; (j < list.size() && count == 0); ++j){
                                  if(newlist.at(i).fileName() == list.at(j).fileName())
                                      ++count;
                              }
                              if(count == 0)
                                  index_new = i;
                          }
                          
                          if(index_new != -1){
                              ui->tableWidget->insertRow(ui->tableWidget->rowCount());
                              QTableWidgetItem *itm = new QTableWidgetItem("");
                              itm->setBackground(QColor(148, 195, 123));
                              ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 0, itm);
                              ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 1, new QTableWidgetItem(newlist.at(index_new).fileName()));
                              ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 2, new QTableWidgetItem("Created"));
                              ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 3, new QTableWidgetItem(newlist.at(index_new).lastModified().toString()));
                              list.append(newlist.at(index_new));
                          }
                          }
                          void MainWindow::on_pushButton_2_clicked()
                          {
                          QFile csv(f_name);
                          
                          if(!csv.open(QFile::WriteOnly))
                              return;
                          
                          QTextStream out(&csv);
                          
                          for(int i = 0; i < ui->tableWidget->rowCount(); ++i)
                              for (int j = 1; j < ui->tableWidget->columnCount(); j++){
                                  QString txt(ui->tableWidget->item(i, j)->text());
                                  out<<txt;
                              }
                          out.flush();
                          csv.close();
                          }
                          

                          Sorry for the indentation.
                          This is the declaration of the global variables in mainwindow.h

                          QString path, f_name;
                          QFileInfoList list;
                          
                          J.HilkJ Offline
                          J.HilkJ Offline
                          J.Hilk
                          Moderators
                          wrote on last edited by
                          #15

                          @Daesos
                          Going through your code, I noticed, you're mixing postfix, prefix in your nested loop to access the Tablewidget Item. I would search there for an out of bounds error.


                          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.

                          1 Reply Last reply
                          1
                          • D Daesos

                            @jsulm I checked and there is no other instance opened. Also, I used another path. The program created the file.csv (empty), then quitted. Application Output: "The program has unexpectedly finished."

                            Since I don't know if I have mistaken something I will post all the mainwindow.cpp code:

                            #include "mainwindow.h"
                            #include "ui_mainwindow.h"
                            #include <QFileDialog>
                            #include <QFileInfo>
                            #include <QTimer>
                            #include <QDateTime>
                            #include <QFile>
                            #include <QTextStream>
                            
                            MainWindow::MainWindow(QWidget *parent) :
                                QMainWindow(parent),
                                ui(new Ui::MainWindow)
                            {
                                ui->setupUi(this);
                            
                                setWindowTitle("DirectoryMonitor");
                                ui->tableWidget->setColumnCount(4);
                                ui->tableWidget->setHorizontalHeaderLabels(QStringList() << "" << "Filename" << "Event" << "Time");
                            
                                f_name = "log_activity.csv";
                            }
                            
                            MainWindow::~MainWindow()
                            {
                                delete ui;
                            }
                            
                            void MainWindow::on_pushButton_clicked()
                            {
                                ui->tableWidget->clearContents();
                                path = QFileDialog::getExistingDirectory(this, tr("Open Directory"), ".", QFileDialog::ShowDirsOnly | QFileDialog::DontResolveSymlinks);
                                ui->lineEdit->setText(path);
                            
                            QDir dir(path);
                            
                            dir.setFilter(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot);
                            dir.setSorting(QDir::Time);
                            list = dir.entryInfoList();
                            
                            for(int i = 0; i < list.size(); ++i){
                                    ui->tableWidget->insertRow(ui->tableWidget->rowCount());
                                    ui->tableWidget->setItem(i, 1, new QTableWidgetItem(list.at(i).fileName()));
                                    ui->tableWidget->setItem(i, 3, new QTableWidgetItem(list.at(i).lastModified().toString()));
                            }
                            
                            int count = 0;
                            
                            for(int i = 0; i < ui->tableWidget->rowCount(); ++i){
                                QTableWidgetItem *itm = ui->tableWidget->item(i, 1);
                                if(itm != 0)
                                   ++count;
                            }
                            //rimuovi righe vuote
                            ui->tableWidget->setRowCount(count);
                            
                            QTimer *time = new QTimer(this);
                            
                            connect(time, SIGNAL(timeout()), this, SLOT(changes()));
                            time->start(3000);
                            }
                            
                            void MainWindow::changes()
                            {
                            QDir dir(path);
                            dir.setFilter(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot);
                            dir.setSorting(QDir::Time);
                            
                            QFileInfoList newlist = dir.entryInfoList();
                            
                            int index_delete = -1;
                            
                            //caso modified e delete file
                            for(int i = 0; i < list.size(); ++i){
                                int count = 0;
                                for(int j = 0; j < newlist.size(); ++j){
                                    if(list.at(i).fileName() == newlist.at(j).fileName()){
                                        ++count;
                                        if(list.at(i).lastModified() != newlist.at(j).lastModified()){
                                            QTableWidgetItem *itm = new QTableWidgetItem("");
                                            itm->setBackground(QColor(109, 158, 235));
                                            ui->tableWidget->setItem(i, 0, itm);
                                            ui->tableWidget->setItem(i, 2, new QTableWidgetItem("Modified"));
                                            ui->tableWidget->setItem(i, 3, new QTableWidgetItem(newlist.at(j).lastModified().toString()));
                                        }
                                    }
                                }
                                if(count == 0){
                                    index_delete = i;
                                }
                            }
                            
                            if(index_delete != -1){
                                QTableWidgetItem *itm = new QTableWidgetItem("");
                                itm->setBackground(QColor(224, 102, 99));
                                ui->tableWidget->setItem(index_delete, 0, itm);
                                if(ui->tableWidget->item(index_delete, 2)->text() != "Deleted")
                                    ui->tableWidget->setItem(index_delete, 3, new QTableWidgetItem(QDateTime::currentDateTime().toString()));
                                ui->tableWidget->setItem(index_delete, 2, new QTableWidgetItem("Deleted"));
                            }
                            
                            //caso new file
                            int index_new = -1;
                            
                            for(int i = 0; i < newlist.size(); ++i){
                                int count = 0;
                                for(int j = 0; (j < list.size() && count == 0); ++j){
                                    if(newlist.at(i).fileName() == list.at(j).fileName())
                                        ++count;
                                }
                                if(count == 0)
                                    index_new = i;
                            }
                            
                            if(index_new != -1){
                                ui->tableWidget->insertRow(ui->tableWidget->rowCount());
                                QTableWidgetItem *itm = new QTableWidgetItem("");
                                itm->setBackground(QColor(148, 195, 123));
                                ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 0, itm);
                                ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 1, new QTableWidgetItem(newlist.at(index_new).fileName()));
                                ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 2, new QTableWidgetItem("Created"));
                                ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 3, new QTableWidgetItem(newlist.at(index_new).lastModified().toString()));
                                list.append(newlist.at(index_new));
                            }
                            }
                            void MainWindow::on_pushButton_2_clicked()
                            {
                            QFile csv(f_name);
                            
                            if(!csv.open(QFile::WriteOnly))
                                return;
                            
                            QTextStream out(&csv);
                            
                            for(int i = 0; i < ui->tableWidget->rowCount(); ++i)
                                for (int j = 1; j < ui->tableWidget->columnCount(); j++){
                                    QString txt(ui->tableWidget->item(i, j)->text());
                                    out<<txt;
                                }
                            out.flush();
                            csv.close();
                            }
                            

                            Sorry for the indentation.
                            This is the declaration of the global variables in mainwindow.h

                            QString path, f_name;
                            QFileInfoList list;
                            
                            JonBJ Online
                            JonBJ Online
                            JonB
                            wrote on last edited by JonB
                            #16

                            @Daesos
                            If you're still having problems with the file (once you've solved the "crash"), try replacing your QFile with a QString, and use https://doc.qt.io/Qt-5/qtextstream.html#QTextStream-3. You should be successfully building up the string of the file content. If that doesn't work, nor will write to file.

                            1 Reply Last reply
                            0
                            • D Offline
                              D Offline
                              Daesos
                              wrote on last edited by Daesos
                              #17

                              I used debugger and when i click on pushButton_2 (save on interface) it returns a Segmentation Fault at "QTableWidgetItem::text".
                              @J.Hilk, I didn't even notice. I edited the increment.

                              Segmentation Fault occurs when I try to access to a NULL pointer, right? So, it might be out of bound.

                              JonBJ 1 Reply Last reply
                              0
                              • D Daesos

                                I used debugger and when i click on pushButton_2 (save on interface) it returns a Segmentation Fault at "QTableWidgetItem::text".
                                @J.Hilk, I didn't even notice. I edited the increment.

                                Segmentation Fault occurs when I try to access to a NULL pointer, right? So, it might be out of bound.

                                JonBJ Online
                                JonBJ Online
                                JonB
                                wrote on last edited by JonB
                                #18

                                @Daesos
                                I don't see save_button in the code you've posted?

                                I notice you have:

                                                ui->tableWidget->setItem(i, 0, itm);
                                                ui->tableWidget->setItem(i, 2, new QTableWidgetItem("Modified"));
                                                ui->tableWidget->setItem(i, 3, new QTableWidgetItem(newlist.at(j).lastModified().toString()));
                                

                                Where do you setItem() on i, 1 ?

                                for(int i = 0; i < ui->tableWidget->rowCount(); ++i)
                                    for (int j = 1; j < ui->tableWidget->columnCount(); j++){
                                        QString txt(ui->tableWidget->item(i, j)->text());
                                        out<<txt;
                                    }
                                

                                Check your accesses on every i, j here. Somewhere you do not have an item at item(i, j)!

                                1 Reply Last reply
                                0
                                • D Offline
                                  D Offline
                                  Daesos
                                  wrote on last edited by Daesos
                                  #19

                                  I've edited the increment:

                                     for(int i = 0; i < ui->tableWidget->rowCount(); ++i)
                                         for (int j = 1; j < ui->tableWidget->columnCount(); ++j)
                                             out<<ui->tableWidget->item(i, j)->text();
                                  

                                  @JonB said in How to save a table in a file:

                                  @Daesos

                                  I notice you have:

                                                  ui->tableWidget->setItem(i, 0, itm);
                                                  ui->tableWidget->setItem(i, 2, new QTableWidgetItem("Modified"));
                                                  ui->tableWidget->setItem(i, 3, new QTableWidgetItem(newlist.at(j).lastModified().toString()));
                                  

                                  Where do you setItem() on i, 1 ?

                                  I've inizialized item at (i, 1) before. Once inizialized the name of the file must not be modified. So I didn't use setItem on i, 1 again.

                                  @Daesos
                                  ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 1, new QTableWidgetItem(newlist.at(index_new).fileName()));

                                  J.HilkJ 1 Reply Last reply
                                  0
                                  • D Daesos

                                    I've edited the increment:

                                       for(int i = 0; i < ui->tableWidget->rowCount(); ++i)
                                           for (int j = 1; j < ui->tableWidget->columnCount(); ++j)
                                               out<<ui->tableWidget->item(i, j)->text();
                                    

                                    @JonB said in How to save a table in a file:

                                    @Daesos

                                    I notice you have:

                                                    ui->tableWidget->setItem(i, 0, itm);
                                                    ui->tableWidget->setItem(i, 2, new QTableWidgetItem("Modified"));
                                                    ui->tableWidget->setItem(i, 3, new QTableWidgetItem(newlist.at(j).lastModified().toString()));
                                    

                                    Where do you setItem() on i, 1 ?

                                    I've inizialized item at (i, 1) before. Once inizialized the name of the file must not be modified. So I didn't use setItem on i, 1 again.

                                    @Daesos
                                    ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 1, new QTableWidgetItem(newlist.at(index_new).fileName()));

                                    J.HilkJ Offline
                                    J.HilkJ Offline
                                    J.Hilk
                                    Moderators
                                    wrote on last edited by
                                    #20

                                    @Daesos said in How to save a table in a file:

                                    for(int i = 0; i < ui->tableWidget->rowCount(); ++i)
                                    for (int j = 1; j < ui->tableWidget->columnCount(); ++j)
                                    out<<ui->tableWidget->item(i, j)->text();

                                    Maybe it's time to #include good old <QDebug>

                                    for(int i = 0; i < ui->tableWidget->rowCount(); ++i)
                                           for (int j = 1; j < ui->tableWidget->columnCount(); ++j){
                                               qDebug() << i << "of" << ui->tableWidget->rowCount() << endl
                                                                 << j << "of" << ui->tableWidget->columnCount();
                                               out<<ui->tableWidget->item(i, j)->text();
                                               qDebug() << QString("Found text at %1 | %2").arg(i).arg(j);
                                           }
                                    

                                    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.

                                    1 Reply Last reply
                                    0
                                    • VRoninV Offline
                                      VRoninV Offline
                                      VRonin
                                      wrote on last edited by VRonin
                                      #21

                                      Replace out<<ui->tableWidget->item(i, j)->text(); with out<<ui->tableWidget->model()->index(i, j).data().tostring(); to prevent segfaults

                                      The problems I highlighted are still present though

                                      @VRonin said in How to save a table in a file:

                                      In your code above you are not:

                                      • Writing any new line to separate rows.
                                      • Writing any column separator
                                      • Escaping column separators inside the data

                                      "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
                                      ~Napoleon Bonaparte

                                      On a crusade to banish setIndexWidget() from the holy land of Qt

                                      D 1 Reply Last reply
                                      3
                                      • VRoninV VRonin

                                        Replace out<<ui->tableWidget->item(i, j)->text(); with out<<ui->tableWidget->model()->index(i, j).data().tostring(); to prevent segfaults

                                        The problems I highlighted are still present though

                                        @VRonin said in How to save a table in a file:

                                        In your code above you are not:

                                        • Writing any new line to separate rows.
                                        • Writing any column separator
                                        • Escaping column separators inside the data
                                        D Offline
                                        D Offline
                                        Daesos
                                        wrote on last edited by Daesos
                                        #22

                                        @VRonin In a previous version I've added both ";" and "\n", but I forgot to write them again.
                                        However I forgot one case: what happen if I did not create/delete/modify any file, folder, or other?
                                        The cells (i, 2) might be empty and here is where the program fails.
                                        I resolved by editing some code:

                                        void MainWindow::on_pushButton_2_clicked()
                                        {
                                        QFile csv(f_name);
                                        
                                        if(!csv.open(QFile::WriteOnly))
                                            return;
                                        
                                        QTextStream out(&csv);
                                        int tmp_column = 0;
                                        
                                        for(int i = 0; i < ui->tableWidget->rowCount(); ++i){
                                            for (int j = 1; j < ui->tableWidget->columnCount(); ++j){
                                                if(ui->tableWidget->item(i, j) != 0)
                                                    out<<ui->tableWidget->item(i, j)->text();
                                                    out<<";";
                                                    tmp_column = j;
                                            }
                                            if(ui->tableWidget->item(i, tmp_column) != 0)
                                                out<<"\n";
                                        }
                                        
                                        out.flush();
                                        csv.close();
                                        }
                                        

                                        It may not be quite good-looking but it works:

                                        0_1531227135676_6d7d870f-2968-47b7-8941-b6ffbaac0431-image.png

                                        I've also prevented segmentation faults like this for example:

                                        ui->tableWidget->setItem(index_delete, 0, itm);
                                            if(ui->tableWidget->item(index_delete, 2) != 0 && ui->tableWidget->item(index_delete, 2)->text() != "Deleted")
                                                ui->tableWidget->setItem(index_delete, 3, new QTableWidgetItem(QDateTime::currentDateTime().toString()));
                                        
                                        1 Reply Last reply
                                        0
                                        • VRoninV Offline
                                          VRoninV Offline
                                          VRonin
                                          wrote on last edited by VRonin
                                          #23

                                          Try naming a folder Ugly; Name and save your model

                                          "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
                                          ~Napoleon Bonaparte

                                          On a crusade to banish setIndexWidget() from the holy land of Qt

                                          D VRoninV 2 Replies Last reply
                                          1

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