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Encoding in the QTableView

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  • mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by mrjj
    #36

    @ro12man3 said:

    And it doesn't work. How to solve that?

    • You really have to provide more info that that :)
      if you insert qDebug() << "f1=" << fields[0] << "f2=" << fields[1];
      does it read in the data correctly ? this is critical.

    • Also you build the hash
      hash[fields[0].toInt()] = fields[1] ;
      but don't use it. ? You dont use it to look up the text.
      QString CityName = hash[value.toInt()];
      return CityName;

    • Also you mix reading in the file with compare value. that is wrong.
      You should not read it in displayText as it will then read file each time
      it draw that column. that is not so good.
      Make Hash a member of the class. (in .h) and just use it
      in displayText. then u can read it once and use it over and over.

    • Read in the text file in the constructor of the delegate;

    ro12man3R 1 Reply Last reply
    0
    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #37

      In addition to what @mrjj wrote: make the hash a member of your delegate.

      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
      0
      • mrjjM mrjj

        @ro12man3 said:

        And it doesn't work. How to solve that?

        • You really have to provide more info that that :)
          if you insert qDebug() << "f1=" << fields[0] << "f2=" << fields[1];
          does it read in the data correctly ? this is critical.

        • Also you build the hash
          hash[fields[0].toInt()] = fields[1] ;
          but don't use it. ? You dont use it to look up the text.
          QString CityName = hash[value.toInt()];
          return CityName;

        • Also you mix reading in the file with compare value. that is wrong.
          You should not read it in displayText as it will then read file each time
          it draw that column. that is not so good.
          Make Hash a member of the class. (in .h) and just use it
          in displayText. then u can read it once and use it over and over.

        • Read in the text file in the constructor of the delegate;

        ro12man3R Offline
        ro12man3R Offline
        ro12man3
        wrote on last edited by
        #38

        @mrjj said:

        • You really have to provide more info that that :)
          if you insert qDebug() << "f1=" << fields[0] << "f2=" << fields[1];
          does it read in the data correctly ? this is critical.

        Yes, I can extract this values. I tested that in QMessageBox.
        More info... http://rghost.ru/7wFZPWC4v This is the project.
        Download link(http://rghost.ru/download/7wFZPWC4v/ccf2cf56d3bbd353e8db12f377907d858f261e23/ccf2cf56d3bbd353e8db12f377907d858f261e23/myfirstviewEDITED.rar)

        It's not very difficult code structure, I don't know why it's not working.

        1 Reply Last reply
        0
        • SGaistS Offline
          SGaistS Offline
          SGaist
          Lifetime Qt Champion
          wrote on last edited by SGaist
          #39

          Hi,

          Because it's not buildable as is.

          MyDelegate::MyDelegate(QObject *parent)
              : QStyledItemDelegate(parent)
          {
              QString line;
              QFile file("1.txt");
              if(file.open(QIODevice::ReadOnly)) {
                  QTextStream in(&file);
                  while(!in.atEnd()) {
                      QString line = in.readLine(); // get a line from file
                      QStringList fields = line.split(","); // KEY point. we ask it to split the text at "," to a list
                      hash[fields[0].toInt()] = fields[1] ; // store name under key
                  }
              } else {
                  qDebug() << "Error opening file";
              }
          }
          
          // this is the key delegate function!
          QString MyDelegate::displayText(const QVariant& value, const QLocale& locale) const {
               return hash.value(value.toInt());
          }
          

          [edit: code cleanup SGaist]

          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
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          • mrjjM Offline
            mrjjM Offline
            mrjj
            Lifetime Qt Champion
            wrote on last edited by
            #40

            oh a tad to late :)
            https://www.dropbox.com/s/3ajogwsoc7n1zjg/myfirstviewEDITED_hash.zip?dl=0

            ro12man3R 2 Replies Last reply
            1
            • SGaistS Offline
              SGaistS Offline
              SGaist
              Lifetime Qt Champion
              wrote on last edited by
              #41

              Note that the build problem isn't with the delegate but with the MainWindow missing slot implementation.

              @mrjj :-D

              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
              • mrjjM mrjj

                oh a tad to late :)
                https://www.dropbox.com/s/3ajogwsoc7n1zjg/myfirstviewEDITED_hash.zip?dl=0

                ro12man3R Offline
                ro12man3R Offline
                ro12man3
                wrote on last edited by ro12man3
                #42

                @mrjj @SGaist oooohhh guys, thank you!! You are amazing!!!

                It's working. !!!

                The problem is SOLVED! THANK YOU VERY MUCH!!

                1 Reply Last reply
                0
                • mrjjM mrjj

                  oh a tad to late :)
                  https://www.dropbox.com/s/3ajogwsoc7n1zjg/myfirstviewEDITED_hash.zip?dl=0

                  ro12man3R Offline
                  ro12man3R Offline
                  ro12man3
                  wrote on last edited by
                  #43

                  @mrjj @SGaist
                  I started to work and I found one bag.
                  My table is:
                  Roberto
                  Jackson
                  1002
                  1

                  And that's my txt file:
                  1002,Hello
                  1,How are you

                  So the result in the table is
                  Roberto
                  Jackson
                  Hello
                  How are you

                  It's good. Correct work.
                  But if I change 1002 to 10--02 then all const values in the table will become like a second value for 10--02. The result will become:
                  Hello
                  Hello
                  Hello
                  How are you

                  You can see that, just edit in table Maria to 10--02 and add 10--02 to txt file. What is that?

                  1 Reply Last reply
                  0
                  • mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #44

                    @ro12man3 said:

                    10--02

                    hi
                    If you change the first field in file to 10--02
                    it it no longer a valid integer.
                    Our hash is Int, String
                    so that mean use int as key and get back string
                    when we read "10--02", and say toInt() we get 0 or something undefined.

                    If you need to use a key that is not really a integer. like 10--02, then
                    you must change the hash to be Qstring, QString and NOT use toInt() when inserting
                    into hash.
                    So make sure your text format fits the Hash or strange things will happen :)

                    ro12man3R 1 Reply Last reply
                    2
                    • mrjjM mrjj

                      @ro12man3 said:

                      10--02

                      hi
                      If you change the first field in file to 10--02
                      it it no longer a valid integer.
                      Our hash is Int, String
                      so that mean use int as key and get back string
                      when we read "10--02", and say toInt() we get 0 or something undefined.

                      If you need to use a key that is not really a integer. like 10--02, then
                      you must change the hash to be Qstring, QString and NOT use toInt() when inserting
                      into hash.
                      So make sure your text format fits the Hash or strange things will happen :)

                      ro12man3R Offline
                      ro12man3R Offline
                      ro12man3
                      wrote on last edited by
                      #45

                      @mrjj Ok. It was

                      // In .h file:
                      QHash<int, QString> hash;
                      ......
                        hash[fields[0].toInt()] = fields[1] ;
                      ......
                      // In .cpp file:
                      QString mapped = hash.value(value.toInt());
                      

                      After editing it's:

                      // In .h file:
                      QHash<QString, QString> hash;
                      ......
                        hash[fields[0]] = fields[1] ;
                      ......
                      // In .cpp file:
                      QString mapped = hash.value(value);
                      

                      Is it correct?

                      1 Reply Last reply
                      1
                      • mrjjM Offline
                        mrjjM Offline
                        mrjj
                        Lifetime Qt Champion
                        wrote on last edited by
                        #46

                        hi
                        yes, seems fine. good work.
                        i think you might need
                        QString mapped = hash.value(value.toString);
                        as value is variant and hash wants string.

                        ro12man3R 1 Reply Last reply
                        2
                        • mrjjM mrjj

                          hi
                          yes, seems fine. good work.
                          i think you might need
                          QString mapped = hash.value(value.toString);
                          as value is variant and hash wants string.

                          ro12man3R Offline
                          ro12man3R Offline
                          ro12man3
                          wrote on last edited by
                          #47

                          @mrjj Wooow I'm so happy, really :D Thank you :) I will study and study and study :)

                          1 Reply Last reply
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