Problem with sorting

[Andrew]

I have got 2 GridView controls: one shows details of a selected row from the other grid. Grid with details has sorting on 3 columns (by default) – image 1. When I change row in master grid, I have got an exception (problem with sorting in the details grid) – image 2:

Object reference not set to an instance of an object.
   w Telerik.Windows.Controls.GridView.AggregatesToGroupFooterAggregatesConverter.<>c__DisplayClass4.<Convert>b__1(AggregateResult f)
   w System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
   w MS.Internal.EnumerableCollectionView.LoadSnapshotCore(IEnumerable source)
   w MS.Internal.EnumerableCollectionView.LoadSnapshot(IEnumerable source)
   w MS.Internal.EnumerableCollectionView.RefreshOverride()
   w System.Windows.Data.CollectionView.Refresh()
   w Telerik.Windows.Controls.GridView.GridViewFooterCell.AggregateResults_CollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
   w System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
   w System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
   w Telerik.Windows.Data.RadObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
   w Telerik.Windows.Data.RadObservableCollection`1.ResumeNotifications()
   w Telerik.Windows.Controls.GridView.GridViewDataControl.CreateAggregateResults()
   w Telerik.Windows.Controls.GridView.GridViewDataControl.OnItemsCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
   w System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
   w Telerik.Windows.Data.DataItemCollection.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
   w Telerik.Windows.Data.DataItemCollection.OnCollectionViewCollectionChanged(NotifyCollectionChangedEventArgs e)
   w Telerik.Windows.Data.DataItemCollection.Telerik.Windows.Data.IWeakEventListener<System.Collections.Specialized.NotifyCollectionChangedEventArgs>.ReceiveWeakEvent(Object sender, NotifyCollectionChangedEventArgs e)
   w Telerik.Windows.Data.WeakEvent.WeakListener`1.Handler(Object sender, TArgs args)
   w Telerik.Windows.Data.QueryableCollectionView.OnCollectionChanged(NotifyCollectionChangedEventArgs args)
   w Telerik.Windows.Data.QueryableCollectionView.RefreshOverride()
   w Telerik.Windows.Data.QueryableCollectionView.RefreshOrDefer()
   w Telerik.Windows.Data.QueryableCollectionView.InvalidatePagingAndRefresh()
   w Telerik.Windows.Data.QueryableCollectionView.OnSortDescriptorsCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
   w System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
   w System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
   w Telerik.Windows.Data.ObservableItemCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
   w Telerik.Windows.Data.RadObservableCollection`1.ResumeNotifications()
   w Telerik.Windows.Data.CollectionHelper.Reset(IEnumerable source, IList target, Func`2 itemConverter)
   w Telerik.Windows.Data.ObservableCollectionManager.HandleCollectionChanged(IList sender, NotifyCollectionChangedEventArgs args)
   w Telerik.Windows.Data.ObservableCollectionManager.Telerik.Windows.Data.IWeakEventListener<System.Collections.Specialized.NotifyCollectionChangedEventArgs>.ReceiveWeakEvent(Object sender, NotifyCollectionChangedEventArgs args)
   w Telerik.Windows.Data.WeakEvent.WeakListener`1.Handler(Object sender, TArgs args)
   w System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
   w System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
   w Telerik.Windows.Data.ObservableItemCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
   w System.Collections.ObjectModel.ObservableCollection`1.ClearItems()
   w Telerik.Windows.Data.RadObservableCollection`1.ClearItems()
   w Telerik.Windows.Data.ObservableItemCollection`1.ClearItems()
   w System.Collections.ObjectModel.Collection`1.Clear()
   w Dashboard.WidgetsClass.GridClass.GridClass.SetColumns(IList data, ObservableCollection`1 kolumny)
   w Dashboard.WidgetsClass.GridClass.GridClass.GetDataCompleted(Object sender, GetDataSetDataCompletedEventArgs e)

After data is loaded I reset SortDescriptors, GroupDescriptors and FilterDescriptors. I think that this is the cause of the problem (it stopped working after I upgraded my project to Telerik 2011.2.920.1040):

Telerik.Windows.Data.GroupDescriptorCollection group = new Telerik.Windows.Data.GroupDescriptorCollection();
Telerik.Windows.Data.SortDescriptorCollection sort = new Telerik.Windows.Data.SortDescriptorCollection();
Telerik.Windows.Data.FilterDescriptorCollection filter = new Telerik.Windows.Data.FilterDescriptorCollection();

void dataGrid_Sorted(object sender, GridViewSortedEventArgs e)
{
     sort.Clear();
     foreach (var sd in dataGrid.SortDescriptors)
          sort.Add(sd);
}


void dataGrid_Filtered(object sender, GridViewFilteredEventArgs e)
{
     filter.Clear();
     foreach (var fd in dataGrid.FilterDescriptors)
          filter.Add(fd);
}


void dataGrid_Grouped(object sender, GridViewGroupedEventArgs e)
{
     group.Clear();
     foreach (var g in dataGrid.GroupDescriptors)
          group.Add(g);
}

// After loading data:
try
{
     if (sort != null)
     {
          dataGrid.SortDescriptors.Clear();
          foreach (var sd in sort)
               dataGrid.SortDescriptors.Add(sd);
     }
     if (group != null)
     {
          dataGrid.GroupDescriptors.Clear();
          foreach (var gd in group)
               dataGrid.GroupDescriptors.Add(gd);
     }
     if (filter != null)
     {
          dataGrid.FilterDescriptors.Clear();
          foreach (var fd in filter)
               dataGrid.FilterDescriptors.Add(fd);
     }
}
catch
{
}

Any suggestions?

[Vera]

Hi Andrew,

Actually, we had a similar issue and it should be resolved. So I would suggest you to download our Latest Internal Build and see if it's working for you.

Best wishes,
Vera
the Telerik team