Groups of items in RadGridView are expanded automatically

[Egor]

Hello, I have RadGridView and grouped items in it. I want to collapse the groups and I can do it. But if any property of item will be changed, the group contains this item will be expanded automatically. I want this group to be expanded regardless of the property changes. Is it bug or feature of RadGridView? Tell me, please, how I can fix it?

I wanted to attach archive with sample project. But forum allows me to attach pictures only

[Egor]

This is code that reproduce my problem

<telerik:RadGridView x:Name="MyRadGridView"
                     AutoExpandGroups="True"
                     AutoGenerateColumns="False">
    <telerik:RadGridView.Columns>
        <telerik:GridViewDataColumn DataMemberBinding="{Binding Name, Mode=OneWay}" />
        <telerik:GridViewDataColumn DataMemberBinding="{Binding Index, Mode=OneWay}" />
    </telerik:RadGridView.Columns>
</telerik:RadGridView>

01.
public partial class MainWindow : Window
02.{
03.    private readonly Random _random = new Random();
04.    private readonly List<Item> _items;
05.
06.    public MainWindow()
07.    {
08.        InitializeComponent();
09.
10.        _items = new List<Item>
11.        {
12.            new Item() { Name = "First", GroupName = "A group" },
13.            new Item() { Name = "Second", GroupName = "A group" },
14.            new Item() { Name = "Third", GroupName = "B group" },
15.            new Item() { Name = "Fourth", GroupName = "B group" },
16.            new Item() { Name = "Fifth", GroupName = "B group" },
17.        };
18.
19.        var itemView = new ListCollectionView(_items);
20.        itemView.GroupDescriptions.Add(new PropertyGroupDescription("GroupName"));
21.
22.        MyRadGridView.ItemsSource = itemView;
23.
24.        Observable.Interval(TimeSpan.FromSeconds(1))
25.                  .Subscribe(OnNext);
26.    }
27.
28.    private void OnNext(long l)
29.    {
30.        foreach (var item in _items)
31.        {
32.            item.Index = _random.Next(10);
33.        }
34.    }
35.}

01.public class Item : INotifyPropertyChanged
02.{
03.    #region Name
04.
05.    private string _name;
06.
07.    public string Name
08.    {
09.        get { return _name; }
10.        set
11.        {
12.            _name = value;
13.            RaisePropertyChanged("Name");
14.        }
15.    }
16.
17.    #endregion
18.
19.    #region GroupName
20.
21.    private string _groupName;
22.
23.    public string GroupName
24.    {
25.        get { return _groupName; }
26.        set
27.        {
28.            _groupName = value;
29.            RaisePropertyChanged("GroupName");
30.        }
31.    }
32.
33.    #endregion
34.
35.    #region Index
36.
37.    private int _index;
38.
39.    public int Index
40.    {
41.        get { return _index; }
42.        set
43.        {
44.            _index = value;
45.            RaisePropertyChanged("Index");
46.        }
47.    }
48.
49.    #endregion
50.
51.    public event PropertyChangedEventHandler PropertyChanged;
52.
53.    [NotifyPropertyChangedInvocator]
54.    protected virtual void RaisePropertyChanged(string propertyName)
55.    {
56.        var handler = PropertyChanged;
57.        if (handler != null)
58.            handler(this, new PropertyChangedEventArgs(propertyName));
59.    }
60.}

[Yoan]

Hi Egor,

Can you try setting RadGridView's GroupRenderMode property to "Flat"? This mode represents our new virtualization mechanism with a completely new item container generator. It should resolve your problem.

I hope this helps. If you need further assistance, do not hesitate to contact us again.

Regards,
Yoan
Progress Telerik

[Egor]

It helps. Thank you, Yoan)