From time to time the System.NullReferenceException throws from XamOutlookBar. It occurs very rarely and I have no idea what is the reason of this problem.
I know that I'm providing extremely little information, because what I do have is just stack trace and no more, but I HOPE someone had already ran into the same problem and coped with the problem.
Here is what I have: it appears on Windows 8.1 with InfragisticsWPF4.OutlookBar.v14.1.dll
System.NullReferenceException: Object reference not set to an instance of an object. at
Infragistics.Windows.OutlookBar.XamOutlookBar.Grid_SizeChanged(Object sender, SizeChangedEventArgs e) at System.Windows.SizeChangedEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget) at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target) at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e) at System.Windows.FrameworkElement.OnRenderSizeChanged(SizeChangedInfo sizeInfo) at System.Windows.ContextLayoutManager.fireSizeChangedEvents() at System.Windows.ContextLayoutManager.UpdateLayout() at System.Windows.UIElement.UpdateLayout() at Infragistics.Windows.OutlookBar.XamOutlookBar.InitializeGroups(Boolean moveToNavigationArea, Boolean fillNavAreaWithDesiredNumberOfGroups) at Infragistics.Windows.OutlookBar.XamOutlookBar.XamOutlookBar_Loaded(Object sender, RoutedEventArgs e) at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs) at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e) at System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent) at System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root) at MS.Internal.LoadedOrUnloadedOperation.DoWork() at System.Windows.Media.MediaContext.FireLoadedPendingCallbacks() at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks() at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget) at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
Do you have any custom styles applied to the XamOutlookBar? When I look at the source code for Grid_SourceChanged the only place I see where a NullReferenceException could occur is when we try to access a private variable called "_splitter". "_splitter" is a variable we set in the controls OnApplyTemplate() method. If you have applied a custom style to the XamOutlookBar which removed the "PART_Splitter" that it looks for then I could see this exception happening.
It turns out we do have a custom style that removes the "PART_Splitter". Today we changed that part of code. Will see if the issue is still occurred...
I'll let you know about results.
Thank you so much!
We're still monitoring for application after a patch for the fix was released.
Seems that it works...