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Reading a file with Qt

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  • E EL-jos

    Yes you are right but except that 65535 makes a maximum size of 64Ko or me I want to send voluminous documents of the order of 30Mo to even 50Mo

    mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by
    #25

    @EL-jos
    then use quint64 instead.

    1 Reply Last reply
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    • E EL-jos

      Yes you are right but except that 65535 makes a maximum size of 64Ko or me I want to send voluminous documents of the order of 30Mo to even 50Mo

      JKSHJ Offline
      JKSHJ Offline
      JKSH
      Moderators
      wrote on last edited by JKSH
      #26

      @EL-jos said in Reading a file with Qt:

      65535 makes a maximum size of 64Ko or me I want to send voluminous documents of the order of 30Mo to even 50Mo

      Then you cannot use quint16. It is too small.

      Use quint32 or even quint64 instead.

      EDIT: @mrjj beat me to it!

      Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

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      • E Offline
        E Offline
        EL-jos
        wrote on last edited by
        #27

        Hey, everybody.
        I was able to solve my problem thanks to your advice, now I am able to send large document in my chatt software but there is a new problem that arises, here is the problem: Which class should I use to send a video file in my chatt software?
        Example: for image exchange, I used the class QImage(Stream for image)but now what class used for Video(Stream video)?

        jsulmJ 1 Reply Last reply
        0
        • E EL-jos

          Hey, everybody.
          I was able to solve my problem thanks to your advice, now I am able to send large document in my chatt software but there is a new problem that arises, here is the problem: Which class should I use to send a video file in my chatt software?
          Example: for image exchange, I used the class QImage(Stream for image)but now what class used for Video(Stream video)?

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

          @EL-jos If it is a file then simply send the binary content of the file.
          There is no need to use a dedicated class for each and every data type.
          https://stackoverflow.com/questions/30288385/how-to-send-a-file-in-qt

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

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          • E Offline
            E Offline
            EL-jos
            wrote on last edited by
            #29

            Yes it is already what I do so I send data in bytes but except that it does not work because I have an error when reading my file like this file is not supported

            jsulmJ 1 Reply Last reply
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            • aha_1980A Offline
              aha_1980A Offline
              aha_1980
              Lifetime Qt Champion
              wrote on last edited by
              #30

              @EL-jos

              Why should a file not be supported if you just send it byte-by-byte? if you store it on a harddisk, it does not matter for the hard disk which file type it is. Its just a number of bytes.

              Same happens when you send it over network.

              Regards

              Qt has to stay free or it will die.

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              • E EL-jos

                Yes it is already what I do so I send data in bytes but except that it does not work because I have an error when reading my file like this file is not supported

                jsulmJ Offline
                jsulmJ Offline
                jsulm
                Lifetime Qt Champion
                wrote on last edited by
                #31

                @EL-jos said in Reading a file with Qt:

                error when reading my file like this file is not supported

                Please explain. Where do you get this error? QFile (I guess you use it for reading) does not care at all about file content.

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

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                • E Offline
                  E Offline
                  EL-jos
                  wrote on last edited by
                  #32

                  In fact after the client sends the byte array, the server receives the bytes and Opens a file in write only mode and writes all the bytes received but except that if I try via VLC to read this file, there is a message that appears like this file is not supported

                  jsulmJ JonBJ 2 Replies Last reply
                  0
                  • E EL-jos

                    In fact after the client sends the byte array, the server receives the bytes and Opens a file in write only mode and writes all the bytes received but except that if I try via VLC to read this file, there is a message that appears like this file is not supported

                    jsulmJ Offline
                    jsulmJ Offline
                    jsulm
                    Lifetime Qt Champion
                    wrote on last edited by
                    #33

                    @EL-jos You should show how you receive the data (whole code not just a small part of it).

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

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                    • E EL-jos

                      In fact after the client sends the byte array, the server receives the bytes and Opens a file in write only mode and writes all the bytes received but except that if I try via VLC to read this file, there is a message that appears like this file is not supported

                      JonBJ Online
                      JonBJ Online
                      JonB
                      wrote on last edited by
                      #34

                      @EL-jos
                      So you need to do a little detective work to help yourself.

                      You have a file which is openable by "VLC" (whatever that is) at the client before you start, right? And you're saying after you have sent it to server it is not openable, right?

                      So start by using a regular file copy, outside of anything Qt, to copy the file from client to server. Make sure you keep the same filename extension. Then: Is the copied file openable on the server? Is it the same size as when you copy via Qt? Use a file content comparison tool (e.g. Windows fc /b), is the file content of the Qt copy identical to that of the non-Qt copy?

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                      • E Offline
                        E Offline
                        EL-jos
                        wrote on last edited by
                        #35

                        Okay I'll try to put your advice into practice then find my mistake if I still can't I'll have to post my code for you to see it

                        1 Reply Last reply
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