NullReferenceException in Grid when Items are empty

[rthorat]

We are using version 2009.1.526.35 of the GridView control. In some situations, we are encountering NullReferenceExceptions when the GridView attempts to layout with no items in it. We have found this problem happening under at least 2 scenarios:

1) Calling ApplyTemplate() on the GridView and all of its template children recursively.

2) Clearing/Removing all items from the GridView (in this case it seems to happen randomly - definitely not always).

In both cases, the problem is in the Measure pass and appears to be a problem with the GridView's panel. Looks like it is trying to access an item or the first item in the Grid when it is empty.

1) Is this a known issue?

2) Is it fixed in a newer version of the control?

Stack Trace:

   at System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgumentargument, ExceptionResource resource)

   at System.ThrowHelper.ThrowArgumentOutOfRangeException()

   at System.Collections.Generic.List`1.get_Item(Int32 index)

   atTelerik.Windows.Controls.GridView.GridViewVirtualizingPanel.GetChildIndexByPhysicalOffset(Doubleoffset)

   atTelerik.Windows.Controls.GridView.GridViewVirtualizingPanel.UpdateFirstVisibleChildIndex(Doubleoffset)

   atTelerik.Windows.Controls.GridView.GridViewVirtualizingPanel.SetVerticalOffset(Doubleoffset)

   atTelerik.Windows.Controls.GridView.GridViewVirtualizingPanel.ResetVerticalOffset()

   atTelerik.Windows.Controls.GridView.BaseVirtualizingPanel.MeasureOverride(SizeavailableSize)

   at System.Windows.FrameworkElement.MeasureCore(Size availableSize)

   at System.Windows.UIElement.Measure(Size availableSize)

   at System.Windows.ContextLayoutManager.UpdateLayout()

   at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Objectarg)

   at System.Windows.Media.MediaContext.InvokeOnRenderCallback.DoWork()

   at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()

   at System.Windows.Media.MediaContext.RenderMessageHandlerCore(ObjectresizedCompositionTarget)

   at System.Windows.Media.MediaContext.RenderMessageHandler(ObjectresizedCompositionTarget)

   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegatecallback, Object args, Boolean isSingleParameter)

   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source,Delegate callback, Object args, Boolean isSingleParameter, DelegatecatchHandler)

[Vlad]

Hello rthorat,

Indeed these problems were fixed and I suggest you to try our latest release Q3 2009 SP1.

Regards,
Vlad
the Telerik team

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