Custom Column Render Problem

[Delvis]

I created my own  "Template" column. Everything works ok. But when I add a child hierarchy and expand any row, the values of that column in the father grid are lost.

Any suggestions on this?

I added part of my code to show the situation.

Code:

public class MyGridTemplateColumn : GridTemplateColumn
{
    public override void Initialize()
    {
        base.Initialize();

        HeaderStyle.Width = Unit.Pixel(105);
        HeaderText = "State";
        UniqueName = "StateCol";

        DataField = "StateId";
        DataType = typeof(byte);

        var _dataSource = new List<KeyValuePair<int, string>>
        {
            new KeyValuePair<int, string>(1, "Active"),
            new KeyValuePair<int, string>(2, "Deleted"),
            new KeyValuePair<int, string>(3, "Inactive"),
            new KeyValuePair<int, string>(6, "Other")
        };

        ItemTemplate = new MyItemTemplate(this.DataField, _dataSource);
        EditItemTemplate = new MyEditItemTemplate(this.DataField, _dataSource);
    }

    public override GridColumn Clone()
    {
        var res = new MyGridTemplateColumn();
        res.CopyBaseProperties(this);

        return res;
    }

    private class MyItemTemplate : ITemplate
    {
        private readonly string _dataField;
        private readonly List<KeyValuePair<int, string>> _dataSource = new List<KeyValuePair<int, string>>();

        public MyItemTemplate(string dataField, List<KeyValuePair<int, string>> origenDatos)
        {
            _dataField = dataField;
            _dataSource = origenDatos;
        }

        public void InstantiateIn(System.Web.UI.Control container)
        {
            var lControl = new LiteralControl { ID = _dataField + "_lControl" };
            lControl.DataBinding += lControl_DataBinding;
            container.Controls.Add(lControl);
        }

        private void lControl_DataBinding(object sender, EventArgs e)
        {
            var l = (LiteralControl)sender;
            var value = l.NamingContainer.GetFieldValue("DataItem." + _dataField);
            if (value != null)
                l.Text = _dataSource.FirstOrDefault(s=>s.Key == (int)value).Value;
        }
    }

    private class MyEditItemTemplate : IBindableTemplate
    {
        private readonly string _dataField;
        private readonly List<KeyValuePair<int, string>> _dataSource = new List<KeyValuePair<int, string>>();

        public MyEditItemTemplate(string dataField, List<KeyValuePair<int, string>> origenDatos)
        {
            _dataField = dataField;
            _dataSource = origenDatos;
        }

        public void InstantiateIn(System.Web.UI.Control container)
        {
            var rcBox = new RadComboBox
            {
                ID = _dataField + "_RadComboBox",
                DataTextField = "Value",
                DataValueField = "Key",
                DataSource = _dataSource
            };

            rcBox.DataBinding += rcBox_DataBinding;
            container.Controls.Add(rcBox);
        }

        public IOrderedDictionary ExtractValues(Control container)
        {
            var dictionary = new OrderedDictionary
            {
                {_dataField, (container.FindControl(_dataField + "_RadComboBox") as RadComboBox).SelectedValue}
            };
            return dictionary;
        }

        private void rcBox_DataBinding(object sender, EventArgs e)
        {
            var rcBox = (RadComboBox)sender;
            var value = rcBox.NamingContainer.GetFieldValue("DataItem." + _dataField);
            rcBox.SelectedValue = value != null ? value.ToString() : string.Empty;
        }
    }
}

Usage:

<telerik:RadGrid ID="RadGrid1" runat="server" DataSourceID="LinqDataSource1" AllowPaging="True" AutoGenerateColumns="False" Width="50%">
    <MasterTableView DataKeyNames="ENTUserAccountId" DataSourceID="LinqDataSource1" PageSize="5">
        <Columns>
            <telerik:GridBoundColumn DataField="UserName" HeaderText="UserName" UniqueName="UserName"/>
            <telerik:GridBoundColumn DataField="Email" HeaderText="Email" UniqueName="Email"/>
            <a:MyGridTemplateColumn />
        </Columns>
        <DetailTables>
            <telerik:GridTableView runat="server" DataSourceID="LinqDataSource2" DataKeyNames="ENTUserAccountId">
                <ParentTableRelation>
                    <telerik:GridRelationFields DetailKeyField="ENTUserAccountId" MasterKeyField="ENTUserAccountId" />
                </ParentTableRelation>
                <Columns>
                    <telerik:GridTemplateColumn DataField="ENTRoleId" HeaderText="Rol" UniqueName="ENTRoleId">
                        <ItemTemplate>
                            <asp:Label ID="ENTRoleIdLabel" runat="server" Text='<%# Eval("ENTRole.RoleName") %>'></asp:Label>
                        </ItemTemplate>
                    </telerik:GridTemplateColumn>
                </Columns>                 
            </telerik:GridTableView>
        </DetailTables>
    </MasterTableView>
</telerik:RadGrid>

<asp:LinqDataSource ID="LinqDataSource1" runat="server" ContextTypeName="TelerikWebApp1.DataClasses1DataContext"
    EntityTypeName="" TableName="ENTUserAccount"/>
        
<asp:LinqDataSource ID="LinqDataSource2" runat="server" ContextTypeName="TelerikWebApp1.DataClasses1DataContext"
    EntityTypeName="" TableName="ENTRoleUserAccount" Where="ENTUserAccountId == @ENTUserAccountId">
        <WhereParameters>
            <asp:SessionParameter Name="ENTUserAccountId" Type="Int32" />
        </WhereParameters>
</asp:LinqDataSource>