Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. QVector
Qt 6.12 LTS is out! See what's new in the release blog

QVector

Scheduled Pinned Locked Moved General and Desktop
31 Posts 9 Posters 27.5k Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • ? Offline
    ? Offline
    A Former User
    wrote on last edited by
    #22

    test.dat contains:

    2
    100
    50
    50
    2.5
    5
    60
    10
    75
    45
    30
    1.6
    2
    45
    25
    25
    15

    So _stages should pick up the 2 at the top of the file. I then have:

    @while (!its.atEnd())
    {
    int i = 0;
    while(i < _stages)
    {
    line = its.readLine();
    _wMasses.push_back(line.toDouble());

    line = its.readLine();
    _fMasses.push_back(line.toDouble());

    line = its.readLine();
    _dMasses.push_back(line.toDouble());

    line = its.readLine();
    _flowRates.push_back(line.toDouble());

    line = its.readLine();
    _burnTimes.push_back(line.toDouble());

    line = its.readLine();
    _thrusts.push_back(line.toDouble());

    line = its.readLine();
    _alphas.push_back(line.toDouble());

    i++;
    }

    line = its.readLine();
    _Mass = line.toDouble();

    line = its.readLine();
    _Alpha = line.toDouble();
    }@

    Which reads the rest of the file.

    1 Reply Last reply
    0
    • ? Offline
      ? Offline
      A Former User
      wrote on last edited by
      #23

      Does it work if you change this line:

      @
      infile.open(QIODevice::ReadOnly);
      @

      to this:

      @
      infile.open(QIODevice::ReadOnly | QIODevice::Text);
      @

      1 Reply Last reply
      0
      • ? Offline
        ? Offline
        A Former User
        wrote on last edited by
        #24

        No, still doesn't work...

        1 Reply Last reply
        0
        • ? Offline
          ? Offline
          A Former User
          wrote on last edited by
          #25

          I had:

          @if (!(infile.open(QIODevice::ReadOnly)))
          {
          return 1;
          }@

          And it goes in and returns 1. Not sure what's going on.

          1 Reply Last reply
          0
          • ? Offline
            ? Offline
            A Former User
            wrote on last edited by
            #26

            Does your process have permissions to read the file? Is some other process locking the file? Is the path correct?

            1 Reply Last reply
            0
            • ? Offline
              ? Offline
              A Former User
              wrote on last edited by
              #27

              My file was either in the wrong location, or I was trying to run my program from the wrong directory. Thank you so much.

              1 Reply Last reply
              0
              • ? Offline
                ? Offline
                A Former User
                wrote on last edited by
                #28

                Meh, we've all been there, done that at some point. :-) Another trick you can use is to use something like this:

                @
                QFileInfo fi( fileName );
                if ( !fi.isReadable() )
                do something
                @

                Glad you got it working in the end.

                1 Reply Last reply
                0
                • ? Offline
                  ? Offline
                  A Former User
                  wrote on last edited by
                  #29

                  Reading input files is always something I struggle with. Now I can get down to the business of writing the code to actually do stuff. Thanks again for everyone's help!

                  1 Reply Last reply
                  0
                  • A Offline
                    A Offline
                    andre
                    wrote on last edited by
                    #30

                    You might want to add some error checking in your parsing code... It is not very save to just assume that your reading and converting worked properly, if you have no control over the input file...

                    1 Reply Last reply
                    0
                    • ? Offline
                      ? Offline
                      A Former User
                      wrote on last edited by
                      #31

                      another option would be to check if the file you want to open exists before trying to open it.
                      Just use something like
                      @if(QFile::exists(filename))
                      {
                      QFile file (filename);
                      if(file.open(QIODevice::ReadOnly)
                      {
                      QByteArray strFileContent = file.readAll();
                      }
                      }@

                      This way its easier to find the error when debugging.

                      PS: Any possible errors are mine and are not to be used by anyone else.

                      1 Reply Last reply
                      0

                      • Login

                      • Login or register to search.
                      • First post
                        Last post
                      0
                      • Categories
                      • Recent
                      • Tags
                      • Popular
                      • Users
                      • Groups
                      • Search
                      • Get Qt
                      • Unsolved