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QString replace %U

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  • sonichyS Offline
    sonichyS Offline
    sonichy
    wrote on last edited by sonichy
    #8

    Change connect lambda [=] to [&], error disappare, what is the difference ?
    New problem: sExec always run the last whatever I click the first, second, third !

    "deepin-draw %U"
    "/usr/bin/display-im6.q16 -nostdin %F"
    "deepin-album %F"
    "/usr/bin/google-chrome-stable %U"
    "deepin-image-viewer --new-window %F"
    
    "deepin-image-viewer --new-window /home/sonichy/Desktop/KuGou.png"
    

    https://github.com/sonichy

    eyllanescE 2 Replies Last reply
    0
    • sonichyS sonichy

      Change connect lambda [=] to [&], error disappare, what is the difference ?
      New problem: sExec always run the last whatever I click the first, second, third !

      "deepin-draw %U"
      "/usr/bin/display-im6.q16 -nostdin %F"
      "deepin-album %F"
      "/usr/bin/google-chrome-stable %U"
      "deepin-image-viewer --new-window %F"
      
      "deepin-image-viewer --new-window /home/sonichy/Desktop/KuGou.png"
      
      eyllanescE Offline
      eyllanescE Offline
      eyllanesc
      wrote on last edited by eyllanesc
      #9

      @sonichy Read the official docs: https://en.cppreference.com/w/cpp/language/lambda, in special Lambda capture section.

      In simple words: with = you are passing values by copy, instead with & you are passing it as a reference. In your initial case "sExec" inside the lambda is a copy of the original. On the other hand, it is not advisable to use & or = (its can cause bugs), it is better to indicate the variables explicitly: [&sExec]

      If you want me to help you develop some work then you can write to my email: e.yllanescucho@gmal.com.

      1 Reply Last reply
      4
      • sonichyS sonichy

        Change connect lambda [=] to [&], error disappare, what is the difference ?
        New problem: sExec always run the last whatever I click the first, second, third !

        "deepin-draw %U"
        "/usr/bin/display-im6.q16 -nostdin %F"
        "deepin-album %F"
        "/usr/bin/google-chrome-stable %U"
        "deepin-image-viewer --new-window %F"
        
        "deepin-image-viewer --new-window /home/sonichy/Desktop/KuGou.png"
        
        eyllanescE Offline
        eyllanescE Offline
        eyllanesc
        wrote on last edited by eyllanesc
        #10

        @sonichy I recommend you not to abuse lambdas, a better option is to save the variables in a property to be able to execute it in a slot:

        QString sExec= ....
        QString sPath = ....
        
        QAction *action = new QAction(...);
        action->setProperty("sExec", sExec);
        action->setProperty("sPath", sPath);
        // TODO
        
        connect(action, &QAction::triggered, this, &Foo::handle_triggered);
        
        void Foo::handle_triggered(){
            if(QAction *action = qobject_cast<QAction *>(sender())){
                QString sExec= action->property("sExec").toString();
                QString sPath = action->property("sPath").toString();
                qDebug() << sExec  << sPath;
            }
        }
        

        If you want me to help you develop some work then you can write to my email: e.yllanescucho@gmal.com.

        sonichyS 1 Reply Last reply
        0
        • eyllanescE eyllanesc

          @sonichy I recommend you not to abuse lambdas, a better option is to save the variables in a property to be able to execute it in a slot:

          QString sExec= ....
          QString sPath = ....
          
          QAction *action = new QAction(...);
          action->setProperty("sExec", sExec);
          action->setProperty("sPath", sPath);
          // TODO
          
          connect(action, &QAction::triggered, this, &Foo::handle_triggered);
          
          void Foo::handle_triggered(){
              if(QAction *action = qobject_cast<QAction *>(sender())){
                  QString sExec= action->property("sExec").toString();
                  QString sPath = action->property("sPath").toString();
                  qDebug() << sExec  << sPath;
              }
          }
          
          sonichyS Offline
          sonichyS Offline
          sonichy
          wrote on last edited by
          #11

          @eyllanesc Move replace out of lambda work fine.

          QString sExec = readSettings(desktop, "Desktop Entry", "Exec");
          sExec.replace(QString("%U"), filepath, Qt::CaseInsensitive);
          sExec.replace(QString("%F"), filepath, Qt::CaseInsensitive);
          connect(action, &QAction::triggered, [=](){
              QProcess *process = new QProcess;
              process->setWorkingDirectory(sPath);
              qDebug() << sExec;
              process->startDetached(sExec, QStringList());
          });
          

          https://github.com/sonichy

          eyllanescE JonBJ 2 Replies Last reply
          0
          • sonichyS sonichy

            @eyllanesc Move replace out of lambda work fine.

            QString sExec = readSettings(desktop, "Desktop Entry", "Exec");
            sExec.replace(QString("%U"), filepath, Qt::CaseInsensitive);
            sExec.replace(QString("%F"), filepath, Qt::CaseInsensitive);
            connect(action, &QAction::triggered, [=](){
                QProcess *process = new QProcess;
                process->setWorkingDirectory(sPath);
                qDebug() << sExec;
                process->startDetached(sExec, QStringList());
            });
            
            eyllanescE Offline
            eyllanescE Offline
            eyllanesc
            wrote on last edited by
            #12

            @sonichy Change [=] to [sPath, sExec]

            If you want me to help you develop some work then you can write to my email: e.yllanescucho@gmal.com.

            1 Reply Last reply
            0
            • sonichyS sonichy

              @eyllanesc Move replace out of lambda work fine.

              QString sExec = readSettings(desktop, "Desktop Entry", "Exec");
              sExec.replace(QString("%U"), filepath, Qt::CaseInsensitive);
              sExec.replace(QString("%F"), filepath, Qt::CaseInsensitive);
              connect(action, &QAction::triggered, [=](){
                  QProcess *process = new QProcess;
                  process->setWorkingDirectory(sPath);
                  qDebug() << sExec;
                  process->startDetached(sExec, QStringList());
              });
              
              JonBJ Offline
              JonBJ Offline
              JonB
              wrote on last edited by
              #13

              @sonichy
              Also you leak the QProcess *process = new QProcess;. Assuming once startDetached() has been called Qt no longer needs the QProcess, try making it a stack instance, you'll have to make sure that works without issue.

              sonichyS 1 Reply Last reply
              0
              • JonBJ JonB

                @sonichy
                Also you leak the QProcess *process = new QProcess;. Assuming once startDetached() has been called Qt no longer needs the QProcess, try making it a stack instance, you'll have to make sure that works without issue.

                sonichyS Offline
                sonichyS Offline
                sonichy
                wrote on last edited by sonichy
                #14

                @JonB Yes , the process do not start !
                deepin-draw "/home/sonichy/Desktop/KuGou.png"

                https://github.com/sonichy

                JonBJ 1 Reply Last reply
                0
                • sonichyS sonichy

                  @JonB Yes , the process do not start !
                  deepin-draw "/home/sonichy/Desktop/KuGou.png"

                  JonBJ Offline
                  JonBJ Offline
                  JonB
                  wrote on last edited by JonB
                  #15

                  @sonichy said in QString replace %U:

                  Yes , the process do not start !

                  Under what circumstances? The way your code above is/was? After you have changed to make QProcess a stack variable? Both?

                  Please try to give some clear detail with your posts. You give so little information, we have to keep asking you for more....

                  sonichyS 1 Reply Last reply
                  1
                  • JonBJ JonB

                    @sonichy said in QString replace %U:

                    Yes , the process do not start !

                    Under what circumstances? The way your code above is/was? After you have changed to make QProcess a stack variable? Both?

                    Please try to give some clear detail with your posts. You give so little information, we have to keep asking you for more....

                    sonichyS Offline
                    sonichyS Offline
                    sonichy
                    wrote on last edited by
                    #16

                    @JonB This is new problem after modify the code, QProcess do not start in lambda !

                    https://github.com/sonichy

                    jsulmJ JonBJ 2 Replies Last reply
                    0
                    • sonichyS sonichy

                      @JonB This is new problem after modify the code, QProcess do not start in lambda !

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

                      @sonichy Would you mind to post the current code, or should we guess what is wrong?

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

                      sonichyS 1 Reply Last reply
                      0
                      • sonichyS sonichy

                        @JonB This is new problem after modify the code, QProcess do not start in lambda !

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

                        @sonichy said in QString replace %U:

                        This is new problem after modify the code

                        Fair enough, I did say you would have see whether it causes problems. This raises a nasty question of what Qt requires the scope/lifetime of the process used in QProcess::startDetached() to be: it cannot be "forever", because we know detached processes survive even exiting the parent program. Maybe it requires it to exist till at least started() signal has been received, I don't know.

                        Actually, hang on! The overload of startDetached you are using is bool QProcess::startDetached(const QString &program, const QStringList &arguments, const QString &workingDirectory = QString(), qint64 *pid = nullptr). That is static!

                        Soooo:

                        • process->setWorkingDirectory(sPath); has no effect (the method signature above takes an optional parameter for the working directory instead).

                        • Your QProcess *process = new QProcess; is not used.

                        • You can write QProcess::startDetached(sExec, QStringList()); instead, no QProcess instance needed, and no leaking.

                        • Given this I find it hard to believe that changing QProcess *process to QProcess process can have any effect....

                        sonichyS 1 Reply Last reply
                        0
                        • jsulmJ jsulm

                          @sonichy Would you mind to post the current code, or should we guess what is wrong?

                          sonichyS Offline
                          sonichyS Offline
                          sonichy
                          wrote on last edited by
                          #19

                          @jsulm Click QAction QProcess do not start, copy qDebug() content to terminal can run.

                          QString sExec = readSettings(desktop, "Desktop Entry", "Exec");
                          sExec.replace(QString("%U"), filepath, Qt::CaseInsensitive);
                          sExec.replace(QString("%F"), filepath, Qt::CaseInsensitive);
                          connect(action, &QAction::triggered, [=](){
                                 QProcess *process = new QProcess;
                                 process->setWorkingDirectory(path);
                                 qDebug() << sExec;
                                 //process->start(sExec);
                                 process->setProgram(sExec);
                                 process->startDetached();
                          });
                          

                          https://github.com/sonichy

                          JonBJ 1 Reply Last reply
                          0
                          • sonichyS sonichy

                            @jsulm Click QAction QProcess do not start, copy qDebug() content to terminal can run.

                            QString sExec = readSettings(desktop, "Desktop Entry", "Exec");
                            sExec.replace(QString("%U"), filepath, Qt::CaseInsensitive);
                            sExec.replace(QString("%F"), filepath, Qt::CaseInsensitive);
                            connect(action, &QAction::triggered, [=](){
                                   QProcess *process = new QProcess;
                                   process->setWorkingDirectory(path);
                                   qDebug() << sExec;
                                   //process->start(sExec);
                                   process->setProgram(sExec);
                                   process->startDetached();
                            });
                            
                            JonBJ Offline
                            JonBJ Offline
                            JonB
                            wrote on last edited by JonB
                            #20

                            @sonichy
                            Is sExec set to the correct full path to the executable? What do you think your process->setWorkingDirectory(path); achieves? Because if you think it is used to locate the executable to run, it is not.

                            The bool QProcess::startDetached(qint64 *pid = nullptr) overload you are now using has a return value. Do you think you ought look at that if you are having a problem?

                            1 Reply Last reply
                            1
                            • JonBJ JonB

                              @sonichy said in QString replace %U:

                              This is new problem after modify the code

                              Fair enough, I did say you would have see whether it causes problems. This raises a nasty question of what Qt requires the scope/lifetime of the process used in QProcess::startDetached() to be: it cannot be "forever", because we know detached processes survive even exiting the parent program. Maybe it requires it to exist till at least started() signal has been received, I don't know.

                              Actually, hang on! The overload of startDetached you are using is bool QProcess::startDetached(const QString &program, const QStringList &arguments, const QString &workingDirectory = QString(), qint64 *pid = nullptr). That is static!

                              Soooo:

                              • process->setWorkingDirectory(sPath); has no effect (the method signature above takes an optional parameter for the working directory instead).

                              • Your QProcess *process = new QProcess; is not used.

                              • You can write QProcess::startDetached(sExec, QStringList()); instead, no QProcess instance needed, and no leaking.

                              • Given this I find it hard to believe that changing QProcess *process to QProcess process can have any effect....

                              sonichyS Offline
                              sonichyS Offline
                              sonichy
                              wrote on last edited by
                              #21

                              @JonB Two method:
                              bool QProcess::startDetached(qint64 *pid = nullptr)

                              [static] bool QProcess::startDetached(const QString &program, const QStringList &arguments, const QString &workingDirectory = QString(), qint64 *pid = nullptr)

                              And static do not start either.

                              QProcess::startDetached(sExec, QStringList(), path);
                              

                              https://github.com/sonichy

                              jsulmJ JonBJ 2 Replies Last reply
                              0
                              • sonichyS sonichy

                                @JonB Two method:
                                bool QProcess::startDetached(qint64 *pid = nullptr)

                                [static] bool QProcess::startDetached(const QString &program, const QStringList &arguments, const QString &workingDirectory = QString(), qint64 *pid = nullptr)

                                And static do not start either.

                                QProcess::startDetached(sExec, QStringList(), path);
                                
                                jsulmJ Offline
                                jsulmJ Offline
                                jsulm
                                Lifetime Qt Champion
                                wrote on last edited by
                                #22

                                @sonichy Please add error handling - QProcess has functionality for that...

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

                                1 Reply Last reply
                                1
                                • sonichyS sonichy

                                  @JonB Two method:
                                  bool QProcess::startDetached(qint64 *pid = nullptr)

                                  [static] bool QProcess::startDetached(const QString &program, const QStringList &arguments, const QString &workingDirectory = QString(), qint64 *pid = nullptr)

                                  And static do not start either.

                                  QProcess::startDetached(sExec, QStringList(), path);
                                  
                                  JonBJ Offline
                                  JonBJ Offline
                                  JonB
                                  wrote on last edited by
                                  #23

                                  @sonichy
                                  Then I do not see that anything you have had so far can have succeeded, but it's most unclear from your comments what that case is.

                                  As per my previous, could you please show what your qDebug() << sExec; is outputting, instead of making us guess?

                                  sonichyS 1 Reply Last reply
                                  0
                                  • JonBJ JonB

                                    @sonichy
                                    Then I do not see that anything you have had so far can have succeeded, but it's most unclear from your comments what that case is.

                                    As per my previous, could you please show what your qDebug() << sExec; is outputting, instead of making us guess?

                                    sonichyS Offline
                                    sonichyS Offline
                                    sonichy
                                    wrote on last edited by
                                    #24

                                    @JonB deepin-draw "/home/sonichy/Desktop/KuGou.png"

                                    https://github.com/sonichy

                                    jsulmJ JonBJ 2 Replies Last reply
                                    0
                                    • sonichyS sonichy

                                      @JonB deepin-draw "/home/sonichy/Desktop/KuGou.png"

                                      jsulmJ Offline
                                      jsulmJ Offline
                                      jsulm
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #25

                                      @sonichy said in QString replace %U:

                                      deepin-draw

                                      This is a relative path. Pass whole path, so it can actually be found...
                                      And please add error handling...

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

                                      1 Reply Last reply
                                      1
                                      • sonichyS sonichy

                                        @JonB deepin-draw "/home/sonichy/Desktop/KuGou.png"

                                        JonBJ Offline
                                        JonBJ Offline
                                        JonB
                                        wrote on last edited by JonB
                                        #26

                                        @sonichy said in QString replace %U:

                                        @JonB deepin-draw "/home/sonichy/Desktop/KuGou.png"

                                        I previously wrote:

                                        Is sExec set to the correct full path to the executable? What do you think your process->setWorkingDirectory(path); achieves? Because if you think it is used to locate the executable to run, it is not.

                                        jsulmJ sonichyS 2 Replies Last reply
                                        0
                                        • JonBJ JonB

                                          @sonichy said in QString replace %U:

                                          @JonB deepin-draw "/home/sonichy/Desktop/KuGou.png"

                                          I previously wrote:

                                          Is sExec set to the correct full path to the executable? What do you think your process->setWorkingDirectory(path); achieves? Because if you think it is used to locate the executable to run, it is not.

                                          jsulmJ Offline
                                          jsulmJ Offline
                                          jsulm
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #27

                                          @JonB Yes, it is said that people often do not read carefully...

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

                                          JonBJ 1 Reply Last reply
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