Hello,
We have received several bug reports from the users of our application that utilizes the XamGrid component. The exception callstack was as follows:
System.NullReferenceException: Object reference not set to an instance of an object. at Infragistics.AutomationPeers.XamGridAutomationPeer.GetChildrenCore() at System.Windows.Automation.Peers.AutomationPeer.EnsureChildren() at System.Windows.Automation.Peers.AutomationPeer.UpdateChildrenInternal(Int32 invalidateLimit) at System.Windows.Automation.Peers.AutomationPeer.UpdateChildren() at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree() at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree() at System.Windows.ContextLayoutManager.fireAutomationEvents() at System.Windows.ContextLayoutManager.UpdateLayout() at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg) at System.Windows.Media.MediaContext.InvokeOnRenderCallback.DoWork() at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks() at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget) at System.Windows.Media.MediaContext.AnimatedRenderMessageHandler(Object resizedCompositionTarget)
I've updated the binaries to the latest service release, but it still occurs from time to time on our users' machines. Hasn't ever happened to any of the developers though. Could you please have a look at why this is happening?
Hello AntonK,
In this thread you can provide some information such as steps to reproduce when using the XamGrid control.
Let me know if you have any questions with this matter. Thank you.
Hello Duane,
We're do not know how to reproduce the error. None of the developers have withessed this exception being thrown, but we receive bug reports from our users a few times a week. Considering the number of our users, it is very seldom, so the reason is obscure. The log shows that they just opened the window with a xamgrid.
Volume 2.
In this thread you can provide a sample on how the control is being used.
Well, there's a window with two xamGrids on it, bound to an ObservableCollection and ListCollectionView respectively. They're heavily restyled to match our design. Editing and column reordering is disabled. We have also applied a few hacks to work around things which we couldn't disable in any other way:
// HACK #1 // Disable mouse capture to prevent flickering in hover effects // Mouse capturing is required when scrolling (OriginalSource = Thumb)// and column resizing (OriginalSource = HeaderCellControl). Mouse.AddGotMouseCaptureHandler(xamGrid, (sender, args) => { if (args.OriginalSource is XamGrid) Mouse.Capture(null); } ); // HACK #2 // Prevent xamGrid from stealing focus when the source ListCollectionView is refreshed. xamGrid.ActiveCellChanging += (sender, args) => { if (!Keyboard.IsKeyDown(Key.Tab)) args.Cancel = true; };
This is just a follow up if you have any questions on using the xamGrid control and if you require any further assistance with this thread.
We have received about 250 crash reports with this error from our users during the last month. However, we still can't reproduce the error ourselves.
Please provide assistance. Have any other xamGrid users reported this issue?
Best regards,AntonK
For this issue I updated CAS-88010-RWNWMJ and you can find this case within the support activity page: https://ko.infragistics.com/Membership/MySupport.aspx.