"Bounds cannot be changed while locked" on GridView update

Question

I have a List called “myResults”. When the list contains at least one item, I’m trying to populate a GridView 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. It’s difficult to troubleshoot, because it does not happen every time. Also, this GridView is a Telerik RadGridView.

Does anyone know how to stop this “bounds cannot be changed while locked” error?

if (myResults.Count > 0) 
{
    Dispatcher.CurrentDispatcher.Invoke(
        DispatcherPriority.Normal, 
        (Action)delegate()
    {
        this.gvMyResults.DataSource = myResults;
    });
}

I've tried this as well, but am getting the same Exception:

_Context.Send(x =>
{
    this.gvMyResults.DataSource = myResults;
}, null);

Exception / Stack-Trace (as requested):

Type=System.InvalidOperationException
Source=Telerik.WinControls
Message=Bounds cannot be changed while locked.
StackTrace:
    at Telerik.WinControls.RadElement.SetBoundsCore(Rectangle bounds)
    at Telerik.WinControls.RadElement.set_Size(Size value)
    at Telerik.WinControls.RadElement.SetLayoutParams(PointF newOffset, SizeF newSize)
    at Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
    at Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
    at Telerik.WinControls.UI.RowsContainerElement.ArrangeOverride(SizeF finalSize)
    at Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
    at Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
    at Telerik.WinControls.UI.ScrollViewElement`1.ArrangeViewElement(RectangleF viewElementRect)
    at Telerik.WinControls.UI.ScrollViewElement`1.ArrangeOverride(SizeF finalSize)
    at Telerik.WinControls.RadElement.ArrangeCore(RectangleF finalRect)
    at Telerik.WinControls.RadElement.Arrange(RectangleF finalRect)
    at Telerik.WinControls.Layouts.ContextLayoutManager.UpdateLayout()
    at Telerik.WinControls.RadElement.UpdateLayout()
    at Telerik.WinControls.UI.GridVisibilityHelper.EnsureRowVisible(GridViewRowInfo rowInfo)
    at Telerik.WinControls.UI.GridTableElement.EnsureRowVisible(GridViewRowInfo rowInfo)
    at Telerik.WinControls.UI.GridTableElement.EnsureCellVisible(GridViewRowInfo rowInfo, GridViewColumn column)
    at Telerik.WinControls.UI.GridTableElement.UpdateViewCore(Object sender, DataViewChangedEventArgs args)
    at Telerik.WinControls.UI.GridTableElement.UpdateView(Object sender, DataViewChangedEventArgs args)
    at Telerik.WinControls.UI.GridTableElement.ProcessTemplateEvent(GridViewEvent eventData)
    at Telerik.WinControls.UI.GridTableElement.Telerik.WinControls.UI.IGridViewEventListener.ProcessEvent(GridViewEvent eventData)
    at Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessCollection(GridViewEvent gridEvent, PriorityWeakReferenceList list, GridEventProcessMode processMode)
    at Telerik.WinControls.UI.GridViewEventProcessEntity.ProcessEvent(GridViewEvent gridEvent)
    at Telerik.WinControls.UI.GridViewSynchronizationService.NotifyListeners(GridViewEvent gridEvent)
    at Telerik.WinControls.UI.GridViewSynchronizationService.FlushEvents()
    at Telerik.WinControls.UI.GridViewSynchronizationService.DispatchEvent(GridViewEvent gridEvent)
    at Telerik.WinControls.UI.GridViewSynchronizationService.RaiseCurrentChanged(GridViewTemplate template, GridViewRowInfo row, GridViewColumn column, Boolean user)
    at Telerik.WinControls.UI.GridViewTemplate.CollectionView_CurrentChanged(Object sender, EventArgs e)
    at System.EventHandler.Invoke(Object sender, EventArgs e)
    at Telerik.WinControls.Data.RadCollectionView`1.OnCurrentChanged(EventArgs args)
    at Telerik.WinControls.Data.RadCollectionView`1.SetCurrentPositionCore(Int32 newPosition, Boolean forceNotify, CurrentChangeReason reason)
    at Telerik.WinControls.Data.RadDataView`1.SyncCurrent(TDataItem item)
    at Telerik.WinControls.Data.RadDataView`1.RebuildData(Boolean notify)
    at Telerik.WinControls.Data.RadDataView`1.RefreshOverride()
    at Telerik.WinControls.Data.RadDataView`1.ProcessCollectionChanged(NotifyCollectionChangedEventArgs args)
    at Telerik.WinControls.Data.RadCollectionView`1.source_CollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
    at Telerik.WinControls.Data.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
    at Telerik.WinControls.Data.RadListSource`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    at Telerik.WinControls.Data.RadListSource`1.EndUpdate(Boolean notifyUpdates)
    at Telerik.WinControls.Data.RadListSource`1.Initialize()
    at Telerik.WinControls.Data.RadListSource`1.Bind(Object dataSource, String dataMember)
    at Telerik.WinControls.Data.RadListSource`1.set_DataSource(Object value)
    at Telerik.WinControls.UI.GridViewTemplate.set_DataSource(Object value)
    at Telerik.WinControls.UI.RadGridView.set_DataSource(Object value)
    at MyProject.MyWindow.<>c__DisplayClass2.<DisplayCallerInfo>b__0() 

Answer 1

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; }));
}
else
{ 
 this.gvMyResults.DataSource = myResults;
}