Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. Exceptions alternative
Forum Updated to NodeBB v4.3 + New Features

Exceptions alternative

Scheduled Pinned Locked Moved General and Desktop
3 Posts 3 Posters 991 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.
  • E Offline
    E Offline
    Exotic_Devel
    wrote on last edited by
    #1

    From what I've been reading, Qt does not use exceptions. So what would be the way to capture errors from some Qt classes? For example QFile.

    1 Reply Last reply
    0
    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #2

      Hi,

      Operation that might fail in Qt are generally in the form of bool methodThatMightFail() so you would check whether the method is successful and if not check the error/errorString method. Some more advanced classes are using a dedicated error class like QSqlError.

      Hope it helps

      Interested in AI ? www.idiap.ch
      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

      1 Reply Last reply
      0
      • Chris KawaC Offline
        Chris KawaC Offline
        Chris Kawa
        Lifetime Qt Champion
        wrote on last edited by
        #3

        In most cases Qt uses error codes or other meaningful return values like null pointers. For example if file can't be opened for whatever reason QFile::open() will return false.

        Often you can also query for the result of some operation. An example of that is "QNetworkReply::error()":http://qt-project.org/doc/qt-5/qnetworkreply.html#error

        If an operation is in some sense detached from the point of invocation (eg. asynchronous) Qt also emits signals. An example of that is "QNetworkAccessManager::sslErrors":http://qt-project.org/doc/qt-5/qnetworkaccessmanager.html#sslErrors

        In rare cases you can also pass an optional variable that will be filled with the result of an operation. An example of that is "QString::toInt()":http://qt-project.org/doc/qt-5/qstring.html#toInt

        If unsure how specific class handles an error refer to the docs. They are usually clear about it.

        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 Extensions
        • Unsolved