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  4. returning empty std::string when converting a QString with a path to an std::string using toStdString
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returning empty std::string when converting a QString with a path to an std::string using toStdString

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  • U Offline
    U Offline
    UbiMiles
    wrote on last edited by
    #1

    input :
    2d923a1f-00dc-4b77-8538-d4c338f3030a-image.png

    output:
    4d91feb7-645e-40ba-8432-5411f9852ec4-image.png

    is it because of the backslash?
    how can I possibly fix this behavior

    S 1 Reply Last reply
    0
    • Christian EhrlicherC Online
      Christian EhrlicherC Online
      Christian Ehrlicher
      Lifetime Qt Champion
      wrote on last edited by
      #2

      Please don't pictures but text - so we can try out the code directly.

      You forgot to flush the output buffer -> see std::endl or std::flush

      Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
      Visit the Qt Academy at https://academy.qt.io/catalog

      U 2 Replies Last reply
      2
      • Christian EhrlicherC Christian Ehrlicher

        Please don't pictures but text - so we can try out the code directly.

        You forgot to flush the output buffer -> see std::endl or std::flush

        U Offline
        U Offline
        UbiMiles
        wrote on last edited by
        #3

        @Christian-Ehrlicher the text is recieved from QML from a FolderDialog
        then converted from URL to QString

        Christian EhrlicherC 1 Reply Last reply
        0
        • U UbiMiles

          @Christian-Ehrlicher the text is recieved from QML from a FolderDialog
          then converted from URL to QString

          Christian EhrlicherC Online
          Christian EhrlicherC Online
          Christian Ehrlicher
          Lifetime Qt Champion
          wrote on last edited by
          #4

          @UbiMiles Did you actually read my answer on why it does not print something?

          Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
          Visit the Qt Academy at https://academy.qt.io/catalog

          1 Reply Last reply
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          • Christian EhrlicherC Christian Ehrlicher

            Please don't pictures but text - so we can try out the code directly.

            You forgot to flush the output buffer -> see std::endl or std::flush

            U Offline
            U Offline
            UbiMiles
            wrote on last edited by
            #5

            @Christian-Ehrlicher as for flushing I am not intending to output the string but using it with an external SDK, the bug caused a weird exception in the disassembler
            and I found out it is because the string is empty

            Christian EhrlicherC U 2 Replies Last reply
            0
            • U UbiMiles

              @Christian-Ehrlicher as for flushing I am not intending to output the string but using it with an external SDK, the bug caused a weird exception in the disassembler
              and I found out it is because the string is empty

              Christian EhrlicherC Online
              Christian EhrlicherC Online
              Christian Ehrlicher
              Lifetime Qt Champion
              wrote on last edited by
              #6

              @UbiMiles The string is not empty. Please provide a minimal, compilable example of your real code. Your code above does not output anything because (third time) you forgot to flush the output buffer.

              Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
              Visit the Qt Academy at https://academy.qt.io/catalog

              U 1 Reply Last reply
              0
              • U UbiMiles

                @Christian-Ehrlicher as for flushing I am not intending to output the string but using it with an external SDK, the bug caused a weird exception in the disassembler
                and I found out it is because the string is empty

                U Offline
                U Offline
                UbiMiles
                wrote on last edited by
                #7

                @UbiMiles oh
                I do see now , my bad.. pardons

                1 Reply Last reply
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                • Christian EhrlicherC Christian Ehrlicher

                  @UbiMiles The string is not empty. Please provide a minimal, compilable example of your real code. Your code above does not output anything because (third time) you forgot to flush the output buffer.

                  U Offline
                  U Offline
                  UbiMiles
                  wrote on last edited by
                  #8

                  @Christian-Ehrlicher
                  when passing the standard library string to a function it causes a runtime error in the disassembler
                  do you have any idea what may be causing such issue

                  Christian EhrlicherC 1 Reply Last reply
                  0
                  • U UbiMiles

                    @Christian-Ehrlicher
                    when passing the standard library string to a function it causes a runtime error in the disassembler
                    do you have any idea what may be causing such issue

                    Christian EhrlicherC Online
                    Christian EhrlicherC Online
                    Christian Ehrlicher
                    Lifetime Qt Champion
                    wrote on last edited by
                    #9

                    @UbiMiles said in returning empty std::string when converting a QString with a path to an std::string using toStdString:

                    when passing the standard library string to a function it causes a runtime error in the disassembler

                    Maybe you mix debug and release dlls which you're not allowed to do so on Windows.
                    No more ideas without any code / minimal compilable example.

                    Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
                    Visit the Qt Academy at https://academy.qt.io/catalog

                    U 1 Reply Last reply
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                    • Christian EhrlicherC Christian Ehrlicher

                      @UbiMiles said in returning empty std::string when converting a QString with a path to an std::string using toStdString:

                      when passing the standard library string to a function it causes a runtime error in the disassembler

                      Maybe you mix debug and release dlls which you're not allowed to do so on Windows.
                      No more ideas without any code / minimal compilable example.

                      U Offline
                      U Offline
                      UbiMiles
                      wrote on last edited by
                      #10

                      @Christian-Ehrlicher
                      I think the porblem has to do with me appending the date and time to my string

                          sampleName.append(QDateTime::currentDateTime().toString("dd.MM.yyyy hh:mm:ss"));
                      
                      
                      U J.HilkJ 2 Replies Last reply
                      0
                      • U UbiMiles

                        @Christian-Ehrlicher
                        I think the porblem has to do with me appending the date and time to my string

                            sampleName.append(QDateTime::currentDateTime().toString("dd.MM.yyyy hh:mm:ss"));
                        
                        
                        U Offline
                        U Offline
                        UbiMiles
                        wrote on last edited by
                        #11

                        @UbiMiles yes
                        testing without appending the date and time works just fine without any crashes

                        1 Reply Last reply
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                        • U UbiMiles

                          @Christian-Ehrlicher
                          I think the porblem has to do with me appending the date and time to my string

                              sampleName.append(QDateTime::currentDateTime().toString("dd.MM.yyyy hh:mm:ss"));
                          
                          
                          J.HilkJ Online
                          J.HilkJ Online
                          J.Hilk
                          Moderators
                          wrote on last edited by J.Hilk
                          #12

                          @UbiMiles said in returning empty std::string when converting a QString with a path to an std::string using toStdString:

                          @Christian-Ehrlicher
                          I think the porblem has to do with me appending the date and time to my string

                              sampleName.append(QDateTime::currentDateTime().toString("dd.MM.yyyy hh:mm:ss"));
                          
                          

                          on windows, a colon (:)is not a valid character for filenames and/or a path


                          annotation, : can and in fact is part of every windows (full) path, but its reserved for the drive letter association


                          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.

                          U 1 Reply Last reply
                          5
                          • J.HilkJ J.Hilk

                            @UbiMiles said in returning empty std::string when converting a QString with a path to an std::string using toStdString:

                            @Christian-Ehrlicher
                            I think the porblem has to do with me appending the date and time to my string

                                sampleName.append(QDateTime::currentDateTime().toString("dd.MM.yyyy hh:mm:ss"));
                            
                            

                            on windows, a colon (:)is not a valid character for filenames and/or a path


                            annotation, : can and in fact is part of every windows (full) path, but its reserved for the drive letter association

                            U Offline
                            U Offline
                            UbiMiles
                            wrote on last edited by
                            #13

                            @J-Hilk said in returning empty std::string when converting a QString with a path to an std::string using toStdString:

                            sampleName.append(QDateTime::currentDateTime().toString("dd.MM.yyyy hh:mm:ss"));
                            

                            thanks a lot, much appreciated sir.

                            1 Reply Last reply
                            0
                            • U UbiMiles

                              input :
                              2d923a1f-00dc-4b77-8538-d4c338f3030a-image.png

                              output:
                              4d91feb7-645e-40ba-8432-5411f9852ec4-image.png

                              is it because of the backslash?
                              how can I possibly fix this behavior

                              S Offline
                              S Offline
                              Spade
                              wrote on last edited by
                              #14
                              This post is deleted!
                              1 Reply Last reply
                              0

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