[Solved] Exception when dynamically changing Items Source + Grouping

[Konrad Sikorski]

Hi,
I have few list of different item and I am using one GridView to display theme dynamically. When user press button1 than I am displaying collection1 which contain items of class1, button2 will display collection2 which contains items of class2, ... . For each class the grid has different set of columns. I have problem when I want to change grouping. 

I am using SL 5.0 and Telerik 2012.3.1129.1050

In attached example please click button "Item1", than "Item2" and than "Items1" and exception will occurs:

System.ArgumentNullException was unhandled by user code
  Message=Value cannot be null.
Parameter name: body
  StackTrace:
       at System.Linq.Expressions.Expression.Lambda(Expression body, String name, Boolean tailCall, IEnumerable`1 parameters)
       at System.Linq.Expressions.Expression.Lambda(Expression body, ParameterExpression[] parameters)
       at Telerik.Windows.Data.Expressions.GroupDescriptorExpressionBuilder.CreateGroupKeySelectorExpression()
       at Telerik.Windows.Data.Expressions.GroupDescriptorExpressionBuilder.get_GroupKeySelectorExpression()
       at Telerik.Windows.Data.Expressions.GroupDescriptorExpressionBuilderBase.CreateQuery()
       at Telerik.Windows.Data.Expressions.GroupDescriptorCollectionExpressionBuilder.CreateChildQuery(GroupDescriptorExpressionBuilder childBuilder)
       at Telerik.Windows.Data.Expressions.GroupDescriptorCollectionExpressionBuilder.CreateQuery()
       at Telerik.Windows.Data.QueryableExtensions.GroupBy(IQueryable source, IEnumerable`1 groupDescriptors)
       at Telerik.Windows.Data.QueryableCollectionView.CreateView()
       at Telerik.Windows.Data.QueryableCollectionView.get_QueryableView()
       at Telerik.Windows.Data.QueryableCollectionView.CreateInternalList()
       at Telerik.Windows.Data.QueryableCollectionView.EnsureInternalList()
       at Telerik.Windows.Data.QueryableCollectionView.get_InternalList()
       at Telerik.Windows.Data.QueryableCollectionView.EnsureRootGroup()
       at Telerik.Windows.Data.QueryableCollectionView.get_RootQCVGGroup()
       at Telerik.Windows.Data.QueryableCollectionView.InternalIndexOf(Object item)
       at Telerik.Windows.Data.QueryableCollectionView.TryRestorePreviousCurrency()
       at Telerik.Windows.Data.QueryableCollectionView.InitializeCurrencyOnRefresh(CurrencyRefreshInfo currencyRefreshInfo)
       at Telerik.Windows.Data.QueryableCollectionView.RefreshOverride()
       at Telerik.Windows.Data.QueryableCollectionView.RefreshInternal()
       at Telerik.Windows.Data.QueryableCollectionView.RefreshOrDefer()
       at Telerik.Windows.Data.QueryableCollectionView.InvalidatePagingAndRefresh()
       at Telerik.Windows.Data.QueryableCollectionView.OnGroupDescriptorsCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e)
       at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
       at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
       at Telerik.Windows.Data.RadObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
       at Telerik.Windows.Data.ObservableItemCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
       at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item)
       at Telerik.Windows.Data.RadObservableCollection`1.InsertItem(Int32 index, T item)
       at System.Collections.ObjectModel.Collection`1.Insert(Int32 index, T item)
       at System.Collections.ObjectModel.Collection`1.System.Collections.IList.Insert(Int32 index, Object value)
       at Telerik.Windows.Data.CollectionHelper.Insert(IList target, IEnumerable newItems, Int32 startingIndex, IEqualityComparer itemComparer)
       at Telerik.Windows.Data.ObservableCollectionManager.HandleCollectionChanged(IList sender, NotifyCollectionChangedEventArgs args)
       at Telerik.Windows.Data.ObservableCollectionManager.Telerik.Windows.Data.IWeakEventListener<System.Collections.Specialized.NotifyCollectionChangedEventArgs>.ReceiveWeakEvent(Object sender, NotifyCollectionChangedEventArgs args)
       at Telerik.Windows.Data.WeakEvent.WeakListener`1.Handler(Object sender, TArgs args)
       at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
       at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
       at Telerik.Windows.Data.RadObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
       at Telerik.Windows.Data.ObservableItemCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
       at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item)
       at Telerik.Windows.Data.RadObservableCollection`1.InsertItem(Int32 index, T item)
       at System.Collections.ObjectModel.Collection`1.Add(T item)
       at telerik_gridView_GroupingIssue.MainPage.ucItems1_Click(Object sender, RoutedEventArgs e)
       at System.Windows.Controls.Primitives.ButtonBase.OnClick()
       at System.Windows.Controls.Button.OnClick()
       at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
       at System.Windows.Controls.Control.OnMouseLeftButtonUp(Control ctrl, EventArgs e)
       at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName, UInt32 flags)
  InnerException: 

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Telerik.Windows.Controls;
using Telerik.Windows.Data;

namespace telerik_gridView_GroupingIssue
{
    public partial class MainPage : UserControl
    {
        ObservableCollection<Item1> _items1 = new ObservableCollection<Item1> { new Item1 { Group1 = "G1.1", Name1 = "N1.1" } };
        ObservableCollection<Item2> _items2 = new ObservableCollection<Item2> { new Item2 { Group2 = "G2.1", Name2 = "N2.1" } };

        public MainPage()
        {
            InitializeComponent();
        }

        private void ucItems1_Click(object sender, RoutedEventArgs e)
        {
            Clear();

            ucItemsGrid.Columns.AddRange(
                    new[]
                    {
                        new GridViewDataColumn{UniqueName = "Name1", Header = "Name 1"},
                    }
                );

            ucItemsGrid.SortDescriptors.Add(
                new SortDescriptor
                {
                    Member = "Name1",
                    SortDirection = ListSortDirection.Descending
                });

            ucItemsGrid.GroupDescriptors.Add(
                new GroupDescriptor
                {
                    Member = "Group1",
                    DisplayContent = "Group 1"
                });

            ucItemsGrid.ItemsSource = _items1;
        }

        private void ucItems2_Click(object sender, RoutedEventArgs e)
        {
            Clear();

            ucItemsGrid.Columns.AddRange(
                    new[]
                    {
                        new GridViewDataColumn{UniqueName = "Name2", Header = "Name 2"},
                    }
                );

            ucItemsGrid.SortDescriptors.Add(
                new SortDescriptor
                {
                    Member = "Name2",
                    SortDirection = ListSortDirection.Descending
                });

            ucItemsGrid.ItemsSource = _items2;
        }

        private void Clear()
        {
            ucItemsGrid.GroupDescriptors.Clear();
            ucItemsGrid.SortDescriptors.Clear();
            ucItemsGrid.Columns.Clear();
            ucItemsGrid.ClearValue(RadGridView.ItemsSourceProperty);
            ucItemsGrid.ItemsSource = null;
            ucItemsGrid.Visibility = Visibility.Visible;
            ucItemsGrid.Rebind();
        }
    }

    public interface IItem
    {
    }

    public class Item1 : IItem
    {
        public string Group1 { get; set; }
        public string Name1 { get; set; }
    }

    public class Item2 : IItem
    {
        public string Group2 { get; set; }
        public string Name2 { get; set; }
    }
}

 

<UserControl x:Class="telerik_gridView_GroupingIssue.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
             mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <StackPanel x:Name="LayoutRoot" Background="White">
        <Button Name="ucItems1" Content="Items1" Click="ucItems1_Click"/>
        <Button Name="ucItems2" Content="Items2" Click="ucItems2_Click"/>
        <telerik:RadGridView Name="ucItemsGrid"
                             AutoGenerateColumns="False"
                             IsReadOnly="True"
                             RowIndicatorVisibility="Collapsed"
                             CanUserFreezeColumns="False"
                             />
    </StackPanel>
</UserControl>

[Yoan]

Hello Konrad,

I am sorry, but I can not find any file attached in this thread. However, I can suggest you to test your project with our lates official release - Q2 2013 SP1 (2013.2.724). What is the result you got with the latest binaries? 

Regards,
Yoan
Telerik