Hi Xceed,

Since the version 4.3 of the DataGrid, a user reported me an NullReferenceException with the following stack trace.

What do you think about that?

Thanks

Cyber Sinh

Une exception de type 'System.NullReferenceException' a été levée :
La référence d'objet n'est pas définie à une instance d'un objet.
à Xceed.Wpf.DataGrid.CustomItemContainerGenerator.EnqueueContainer(DependencyObject container, Object item)
à Xceed.Wpf.DataGrid.CustomItemContainerGenerator.RemoveContainer(DependencyObject container, Object dataItem)
à Xceed.Wpf.DataGrid.CustomItemContainerGenerator.RemoveGeneratedItem(Int32 index, IList`1 removedContainers)
à Xceed.Wpf.DataGrid.CustomItemContainerGenerator.RemoveGeneratedItems(Int32 startIndex, Int32 endIndex, IList`1 removedContainers)
à Xceed.Wpf.DataGrid.CustomItemContainerGenerator.HandleSameLevelGroupRemove(GeneratorNode firstChild, Int32& countRemoved, Int32& genCountRemoved, Int32& removeIndex, NotifyCollectionChangedEventArgs e, IList`1 removedContainers)
à Xceed.Wpf.DataGrid.CustomItemContainerGenerator.HandleParentGroupRemove(GeneratorNode parent, Int32& countRemoved, Int32& genCountRemoved, Int32& removeIndex, NotifyCollectionChangedEventArgs e, IList`1 removedContainers)
à Xceed.Wpf.DataGrid.CustomItemContainerGenerator.OnGeneratorNodeGroupsCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
à Xceed.Wpf.DataGrid.NotifyCollectionChangedGeneratorNode.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
à Xceed.Wpf.DataGrid.GeneratorNodeFactory.ReceiveWeakEvent(Type managerType, Object sender, EventArgs e)
à System.Windows.WeakEventManager.DeliverEventToList(Object sender, EventArgs args, ListenerList list)
à System.Windows.WeakEventManager.DeliverEvent(Object sender, EventArgs args)
à System.Collections.Specialized.CollectionChangedEventManager.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
à System.Collections.ObjectModel.ReadOnlyObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
à System.Collections.ObjectModel.ReadOnlyObservableCollection`1.HandleCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
à System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
à System.Collections.ObjectModel.ObservableCollection`1.RemoveItem(Int32 index)
à System.Collections.ObjectModel.Collection`1.Remove(T item)
à Xceed.Wpf.DataGrid.DataGridCollectionViewGroup.RemoveGroup(DataGridCollectionViewGroup group)
à Xceed.Wpf.DataGrid.DataGridCollectionViewGroup.RemoveRawItemAt(Int32 index)
à Xceed.Wpf.DataGrid.DataGridCollectionView.RemoveRawItemInGroup(IList`1 rawItems)
à Xceed.Wpf.DataGrid.DataGridCollectionView.RemoveSourceItem(Int32 startIndex, Int32 count)
à Xceed.Wpf.DataGrid.DataGridCollectionView.ExecuteSourceItemOperation(DeferredOperation deferredOperation, Boolean& refreshForced)
à Xceed.Wpf.DataGrid.DeferredOperationManager.Process(Boolean processAll)
à Xceed.Wpf.DataGrid.DataGridCollectionViewBase.DeferRefreshHelper.Dispose()
// Items deletion

Hi,

Thanks for bringing this to our attention. 

The developer has made a quick fix for you to test, please find it attached. 

Please let me know if this solves the issue on your side. 

Hi Michel,

 Thanks for the quick fix.

I found an another exception while deleting items. Any help would be appreciated.

Here is the stack trace:

Une exception de type 'System.ArgumentOutOfRangeException' a été levée :
startIndex must be equal to or greater than zero. Nombre del parámetro: startIndex
en Xceed.Wpf.DataGrid.SelectionRange..ctor(Int32 startIndex, Int32 endIndex)
en Xceed.Wpf.DataGrid.SelectedItemsStorage.OffsetIndex(Int32 startIndex, Int32 offset)
en Xceed.Wpf.DataGrid.SelectionChanger.UpdateSelectedItemsInChangeOfDataGridContext(Boolean itemsSourceChanged)
en Xceed.Wpf.DataGrid.SelectionManager.CommitSelectionChanger(SelectionChanger selectionChanger, Boolean itemsSourceChanged)
en Xceed.Wpf.DataGrid.SelectionManager.End(Boolean itemsSourceChanged, Boolean allowCancelingOfSelection, Boolean allowSynchronizeSelectionWithCurrent)
en Xceed.Wpf.DataGrid.SelectionManager.UpdateSelectionAfterSourceCollectionChanged(DataGridContext dataGridContext, NotifyCollectionChangedEventArgs e)
en Xceed.Wpf.DataGrid.DataGridContext.Items_CollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
en Xceed.Wpf.DataGrid.DataGridContext.System.Windows.IWeakEventListener.ReceiveWeakEvent(Type managerType, Object sender, EventArgs e)
en System.Windows.WeakEventManager.DeliverEventToList(Object sender, EventArgs args, ListenerList list)
en System.Windows.WeakEventManager.DeliverEvent(Object sender, EventArgs args)
en System.Collections.Specialized.CollectionChangedEventManager.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
en System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
en System.Windows.Data.CollectionView.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
en System.Windows.Controls.ItemCollection.System.Windows.IWeakEventListener.ReceiveWeakEvent(Type managerType, Object sender, EventArgs e)
en System.Windows.WeakEventManager.DeliverEventToList(Object sender, EventArgs args, ListenerList list)
en System.Windows.WeakEventManager.DeliverEvent(Object sender, EventArgs args)
en System.Collections.Specialized.CollectionChangedEventManager.OnCollectionChanged(Object sender, NotifyCollectionChangedEventArgs args)
en System.Windows.Data.CollectionView.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
en Xceed.Wpf.DataGrid.DataGridCollectionViewBase.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
en Xceed.Wpf.DataGrid.DataGridCollectionView.RemoveRawItemInGroup(IList`1 rawItems)
en Xceed.Wpf.DataGrid.DataGridCollectionView.RemoveSourceItem(Int32 startIndex, Int32 count)
en Xceed.Wpf.DataGrid.DataGridCollectionView.ExecuteSourceItemOperation(DeferredOperation deferredOperation, Boolean& refreshForced)
en Xceed.Wpf.DataGrid.DeferredOperationManager.Process(Boolean processAll)
en Xceed.Wpf.DataGrid.DataGridCollectionViewBase.DeferRefreshHelper.Dispose()
// items deletion
 

Hi, 

Please note that this has been fixed in the latest release which was released today.

You can download it from the following link:

http://xceed.com/Grid_WPF_Intro.html