“Bounds cannot be changed while locked” on GridView update

2 posts, 0 answers
  1. Will
    Will avatar
    11 posts
    Member since:
    Apr 2013

    Posted 30 Jul 2013 Link to this post

    I have a List called “myResults”. When the list contains at least one item, I’m trying to populate a RadGridView w/ info for the list; the GridView is called “gvMyResults”. However, sometimes, during this update of the DataSource, I get an exception saying, “Bounds cannot be changed while locked”, and a red X is displayed across my GridView. I added this Dispatcher wrapper around my update, but I’m still seeing the same error sometimes. It’s difficult to troubleshoot, because it does not happen every time. I've tried fixing this two separate ways, but they both still show the occasional error.  Does anyone know how to stop this “bounds cannot be changed while locked” error?

    First attempt to fix this problem:

    Dispatcher.CurrentDispatcher.Invoke(DispatcherPriority.Normal, (Action)delegate()
        this.gvMyResults.DataSource = myResults;

    Second attempt to fix this problem:

    _Context.Send(x =>
        this.gvMyResults.DataSource = myResults;
    }, null);
  2. Peter
    Peter avatar
    1160 posts

    Posted 02 Aug 2013 Link to this post

    Hi Will, 

    Thank you for writing.

    This error indicates that the grid is not in valid state. I noticed in the code snippet that you update the datasource asynchronously and I would like to clarify that all UI controls are not thread safe controls in the whole Windows Forms UI platform. Here is an article on MSDN
    describing how to make thread-safe Winforms UI application. This means that RadGridView is not thread safe as well and cannot be used outside the main UI thread. You should use an Invoke to update the controls in cross threading scenario. For example:
    if (gvMyResults.InvokeRequired) 
        gvMyResults.Invoke(new MethodInvoker(() => { this.gvMyResults.DataSource = myResults; }));
       this.gvMyResults.DataSource = myResults;

    I hope this helps.

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