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How to pass String Value in decimal to QlineEdit?

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  • jsulmJ jsulm

    @Wasee said in How to pass String Value in decimal to QlineEdit?:

    "sudo devmem2 0x80000000"

    Do you realise that your string contains not only a number but allso non-number string ("sudo devmem2 ")?
    That part of course can't be converted to a number.
    You need first to extract the hex-number part and only convert that part to a number.
    You can use https://doc.qt.io/qt-5/qstring.html#split to split your string using "0x" as separator.

    JonBJ Offline
    JonBJ Offline
    JonB
    wrote on last edited by JonB
    #9

    @jsulm
    I think you need to clean your reading glasses and try again... ;-)

    The OP is using that string as argument to QProcess::start(), not as the string to parse!

    @Wasee

    QProcess Temp_reading;
    std:: string ct_value=Temp_reading.start("sudo devmem2 0x80000000");
    QString str (QString::fromStdString(ct_value));
    

    void QProcess::start() does not return any value, so this won't compile, will it....

    Can you just slow down a bit. What are you actually trying to do? I can only guess you have in mind:

    Temp_reading.start("sudo devmem2 0x80000000");
    Temp_reading.waitForFinished();
    QString output(Temp_reading.readAllStandardOutput());
    bool ok;
    int num = output.toInt(&ok, 0);
    

    Actually I see you had this earlier. All you needed to do was do the QString::toInt() on what you got back followed by QString::number() to put it into the line edit. And if that is delivering the right answer have a look at the output from the command which you are trying to parse.

    P.S.
    You originally said the number you need to parse is (like) 0x1. I showed you the above code with output.toInt(&ok, 0); is how to do that. If you are using QString::toDouble() as you show that will not work, as it cannot parse a leading 0x.

    WaseeW 1 Reply Last reply
    2
    • WaseeW Offline
      WaseeW Offline
      Wasee
      wrote on last edited by
      #10

      @jsulm Hi;
      I followed following code to split the string
      /@
      QString band1_2="sudo devmem2 0x80000000 w 0x";
      QString str = QStringLiteral("sudo devmem2 0x80000000 w 0x");
      QStringList list1 = str.split(QLatin1Char('.'));
      qDebug()<<"Split:"<<list1;
      @/
      Its giving me value like "11". But it is not passing to lineedit why? Even I code to convert into integer below.
      QString list;
      bool ok;
      int d;
      d = Qstring(list).toInt(&ok);
      ui->lineedit->setText(d);

      Thanks in advance

      jsulmJ 1 Reply Last reply
      0
      • WaseeW Wasee

        @jsulm Hi;
        I followed following code to split the string
        /@
        QString band1_2="sudo devmem2 0x80000000 w 0x";
        QString str = QStringLiteral("sudo devmem2 0x80000000 w 0x");
        QStringList list1 = str.split(QLatin1Char('.'));
        qDebug()<<"Split:"<<list1;
        @/
        Its giving me value like "11". But it is not passing to lineedit why? Even I code to convert into integer below.
        QString list;
        bool ok;
        int d;
        d = Qstring(list).toInt(&ok);
        ui->lineedit->setText(d);

        Thanks in advance

        jsulmJ Offline
        jsulmJ Offline
        jsulm
        Lifetime Qt Champion
        wrote on last edited by
        #11

        @Wasee said in How to pass String Value in decimal to QlineEdit?:

        QString list;
        bool ok;
        int d;
        d = Qstring(list).toInt(&ok);

        This does not make sense at all: you create a string from an empty string (list) and then try to convert it to int.

        Please read once more what I wrote. I never suggested to split using '."

        But actually you should read what @JonB suggested, as my answer was based on my misunderstanding.

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

        1 Reply Last reply
        1
        • JonBJ JonB

          @jsulm
          I think you need to clean your reading glasses and try again... ;-)

          The OP is using that string as argument to QProcess::start(), not as the string to parse!

          @Wasee

          QProcess Temp_reading;
          std:: string ct_value=Temp_reading.start("sudo devmem2 0x80000000");
          QString str (QString::fromStdString(ct_value));
          

          void QProcess::start() does not return any value, so this won't compile, will it....

          Can you just slow down a bit. What are you actually trying to do? I can only guess you have in mind:

          Temp_reading.start("sudo devmem2 0x80000000");
          Temp_reading.waitForFinished();
          QString output(Temp_reading.readAllStandardOutput());
          bool ok;
          int num = output.toInt(&ok, 0);
          

          Actually I see you had this earlier. All you needed to do was do the QString::toInt() on what you got back followed by QString::number() to put it into the line edit. And if that is delivering the right answer have a look at the output from the command which you are trying to parse.

          P.S.
          You originally said the number you need to parse is (like) 0x1. I showed you the above code with output.toInt(&ok, 0); is how to do that. If you are using QString::toDouble() as you show that will not work, as it cannot parse a leading 0x.

          WaseeW Offline
          WaseeW Offline
          Wasee
          wrote on last edited by
          #12

          @JonB Hi;
          How I can resolve problem i didn't understand.Please write piece of code.
          thanks

          jsulmJ 1 Reply Last reply
          0
          • WaseeW Wasee

            @JonB Hi;
            How I can resolve problem i didn't understand.Please write piece of code.
            thanks

            jsulmJ Offline
            jsulmJ Offline
            jsulm
            Lifetime Qt Champion
            wrote on last edited by
            #13

            @Wasee said in How to pass String Value in decimal to QlineEdit?:

            .Please write piece of code

            He already did.
            What is not clear?

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

            1 Reply Last reply
            1
            • WaseeW Offline
              WaseeW Offline
              Wasee
              wrote on last edited by
              #14

              @jsulm ;
              Thanks!
              But I am getting error of invalid conversion from int to const string for lineedit.

              ui->lineedit->setText(num);

              jsulmJ 1 Reply Last reply
              0
              • WaseeW Wasee

                @jsulm ;
                Thanks!
                But I am getting error of invalid conversion from int to const string for lineedit.

                ui->lineedit->setText(num);

                jsulmJ Offline
                jsulmJ Offline
                jsulm
                Lifetime Qt Champion
                wrote on last edited by jsulm
                #15

                @Wasee Do you understand that setText expects a string, not int?

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

                1 Reply Last reply
                3
                • WaseeW Offline
                  WaseeW Offline
                  Wasee
                  wrote on last edited by
                  #16

                  Hi; everyone;
                  I am unable to fix my problem. Please provide exact information to do that.

                  jsulmJ 1 Reply Last reply
                  0
                  • WaseeW Wasee

                    Hi; everyone;
                    I am unable to fix my problem. Please provide exact information to do that.

                    jsulmJ Offline
                    jsulmJ Offline
                    jsulm
                    Lifetime Qt Champion
                    wrote on last edited by
                    #17

                    @Wasee said in How to pass String Value in decimal to QlineEdit?:

                    Please provide exact information to do that

                    I will do once more your work, but last time now. I will not spend more of my time if you refuse to learn basics.
                    Go to https://doc.qt.io/qt-5/qlineedit.html#text-prop and check what the type is.
                    Type is QString.
                    C++ most basic knowledge: QString != int.
                    So, you can't pass an int as parameter to QLineEdit::setText, because setText() expects a QString.
                    I really fail to understand what is not clear about it?!
                    Maybe you should read a C++ book?

                    Temp_reading.start("sudo devmem2 0x80000000");
                    Temp_reading.waitForFinished();
                    QString output(Temp_reading.readAllStandardOutput());
                    ui->lineedit->setText(output);
                    

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

                    1 Reply Last reply
                    1
                    • WaseeW Offline
                      WaseeW Offline
                      Wasee
                      wrote on last edited by
                      #18

                      @jsulm Hi;
                      Its giving me Values continuous but I need to print these values after 0x in integer form in line-edit.
                      (0xb6f44000):0x11EACAC
                      (0xb6efe00):0x11EACAC
                      (0xb6fd4000):0x11EACAC
                      (0xb6fde000):0x11EACAC

                      jsulmJ 1 Reply Last reply
                      0
                      • WaseeW Wasee

                        @jsulm Hi;
                        Its giving me Values continuous but I need to print these values after 0x in integer form in line-edit.
                        (0xb6f44000):0x11EACAC
                        (0xb6efe00):0x11EACAC
                        (0xb6fd4000):0x11EACAC
                        (0xb6fde000):0x11EACAC

                        jsulmJ Offline
                        jsulmJ Offline
                        jsulm
                        Lifetime Qt Champion
                        wrote on last edited by
                        #19

                        @Wasee What's wrong with https://doc.qt.io/qt-5/qstring.html#number-1?

                        d = Qstring(list).toInt(&ok, 16); // Since you handle hex numbers you need to tell toInt that it is a hex number - so pass 16 as base
                        ui->lineedit->setText(QString::number(d));
                        

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

                        1 Reply Last reply
                        1
                        • WaseeW Offline
                          WaseeW Offline
                          Wasee
                          wrote on last edited by
                          #20

                          @jsulm Hi;
                          Its giving me value 0 in my lineedit.

                          jsulmJ 1 Reply Last reply
                          0
                          • WaseeW Wasee

                            @jsulm Hi;
                            Its giving me value 0 in my lineedit.

                            jsulmJ Offline
                            jsulmJ Offline
                            jsulm
                            Lifetime Qt Champion
                            wrote on last edited by
                            #21

                            @Wasee That means that the conversion from string to int failed. I'm now out of this thread. Debug your code to see what happens and fix the issues...

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

                            1 Reply Last reply
                            0
                            • J.HilkJ Offline
                              J.HilkJ Offline
                              J.Hilk
                              Moderators
                              wrote on last edited by
                              #22
                              Temp_reading.start("sudo devmem2 0x80000000");
                              Temp_reading.waitForFinished();
                              QString output(Temp_reading.readAllStandardOutput());
                              output = output.replace("(", "").replace(")", "").replace(":", "");
                              auto split = output.split("0x");
                              QString str("%1:%2");
                              str= str.arg(split.at(1).toLongLong(nullptr, 16)).arg(split.at(2).toLongLong(nullptr, 16));
                              ui->lineedit->setText(str);
                              

                              alt text


                              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
                              2
                              • WaseeW Offline
                                WaseeW Offline
                                Wasee
                                wrote on last edited by
                                #23

                                @J-Hilk Hi;
                                I am still getting error "split does not name a type" and "split is not declare in this scope" and "nullptr was not declared in this scope"
                                thanks

                                J.HilkJ 1 Reply Last reply
                                0
                                • WaseeW Wasee

                                  @J-Hilk Hi;
                                  I am still getting error "split does not name a type" and "split is not declare in this scope" and "nullptr was not declared in this scope"
                                  thanks

                                  J.HilkJ Offline
                                  J.HilkJ Offline
                                  J.Hilk
                                  Moderators
                                  wrote on last edited by
                                  #24

                                  @Wasee said in How to pass String Value in decimal to QlineEdit?:

                                  "nullptr was not declared in this scope"

                                  impossible if you're using c++11 or later !

                                  split does not name a type

                                  either you forgot auto or you're really not using c++11. Split it is of type QStringList


                                  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
                                  • WaseeW Offline
                                    WaseeW Offline
                                    Wasee
                                    wrote on last edited by
                                    #25

                                    @J-Hilk Hi;
                                    how I can solve this issue?

                                    J.HilkJ 1 Reply Last reply
                                    0
                                    • WaseeW Wasee

                                      @J-Hilk Hi;
                                      how I can solve this issue?

                                      J.HilkJ Offline
                                      J.HilkJ Offline
                                      J.Hilk
                                      Moderators
                                      wrote on last edited by
                                      #26

                                      @Wasee add c++11 to your compiler call


                                      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
                                      • WaseeW Offline
                                        WaseeW Offline
                                        Wasee
                                        wrote on last edited by
                                        #27

                                        @J-Hilk Hi;
                                        Problem solved but I need little bit change its giving me value 0:108280000, I didn't need 0: in this value how I can remove it.

                                        jsulmJ J.HilkJ 2 Replies Last reply
                                        0
                                        • WaseeW Wasee

                                          @J-Hilk Hi;
                                          Problem solved but I need little bit change its giving me value 0:108280000, I didn't need 0: in this value how I can remove it.

                                          jsulmJ Offline
                                          jsulmJ Offline
                                          jsulm
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #28

                                          @Wasee said in How to pass String Value in decimal to QlineEdit?:

                                          how I can remove it

                                          How about doing what you already did in this thread: use split() method and ':' as split character.

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

                                          1 Reply Last reply
                                          0

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