Confusion regarding Cell binding to a dynamic DataTable

[Noah]

Perhaps I am simply misunderstanding the correct way to bind to a given cell in general, but here's my problem.

I have a grid full of cells of type StatisticCell which looks like this:

[DataContract]
public class StatisticCell
{
    [DataMember]
    public string Value { get; set; }

    [DataMember]
    public bool IsSelected { get; set; }

    public StatisticCell(string value, bool isSelected)
    {
        Value = value;
        IsSelected = isSelected;
    }
}

Which is bound dynamically on the client into a RadGridView using the DataTable class provided here.

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

using Telerik.Data;
using Telerik.Windows.Controls;

using DFA.Client.QueryToolService;
using DFA.Client.ValueConverter;

namespace DFA.Client.QueryTool.Control.Panes
{
    public partial class StatisticsContent : UserControl
    {
        public StatisticsContent()
        {
            InitializeComponent();
        }

        public string Title
        {
            get { return "Statistics"; }
        }

        private DataTable _DataTable;

        public void LoadStatistics(ObservableCollection<StatisticRow> rows)
        {
            _DataTable = new DataTable();

            foreach (var axis in rows.First().Data.Keys)
            {
                _DataTable.Columns.Add(new DataColumn() { ColumnName = axis, DataType = typeof(StatisticCell) });
            }

            foreach (StatisticRow row in rows)
            {
                var dataRow = _DataTable.NewRow();

                foreach (var axis in row.Data.Keys)
                {
                    dataRow[axis] = row.Data[axis];
                }

                _DataTable.Rows.Add(dataRow);
            }

            _StatisticsGridView.ItemsSource = _DataTable;
        }


        private void _StatisticsGridView_BeginningEdit(object sender, Telerik.Windows.Controls.GridViewBeginningEditRoutedEventArgs e)
        {

        }

        private void _ApplyButton_Click(object sender, RoutedEventArgs e)
        {
            Cursor = Cursors.Wait;
        }

        private void _ResetButton_Click(object sender, RoutedEventArgs e)
        {
        }

        private void _StatisticsGridView_AutoGeneratingColumn(object sender, GridViewAutoGeneratingColumnEventArgs e)
        {
            e.Column.CellTemplate = (DataTemplate)Resources["_CellTemplate"];
        }
    }
}

With XAML:

<UserControl x:Class="DFA.Client.QueryTool.Control.Panes.StatisticsContent"
    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:converters="clr-namespace:DFA.Client.ValueConverter"
    mc:Ignorable="d"
   d:DesignHeight="300" d:DesignWidth="400"
   xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation">
    <UserControl.Resources>
        <converters:BooleanToBackgroundConverter x:Key="BooleanToBackgroundConverter"/>

        <DataTemplate x:Name="_CellTemplate" >
            <StackPanel  Orientation="Horizontal" Background="Yellow" >
                <TextBlock Text="{Binding Path=Value}">
                </TextBlock>
            </StackPanel>
        </DataTemplate>
    </UserControl.Resources>
    <Grid x:Name="LayoutRoot" Background="White">
        <telerik:RadGridView
                x:Name="_StatisticsGridView"
                CanUserReorderColumns="False"
                CanUserInsertRows="False" CanUserDeleteRows="False" CanUserFreezeColumns="False"
                ShowGroupPanel="False" ShowColumnHeaders="True"
                AutoGenerateColumns="True"
                CanUserSelect="False" BeginningEdit="_StatisticsGridView_BeginningEdit"
                Margin="0,0,12,49" SelectionUnit="Cell" IsFilteringAllowed="False" RowIndicatorVisibility="Collapsed" AutoGeneratingColumn="_StatisticsGridView_AutoGeneratingColumn">
        </telerik:RadGridView>

        <Button Content="Apply" Height="23" HorizontalAlignment="Right" Margin="0,0,100,12" Name="_ApplyButton" VerticalAlignment="Bottom" Width="75" Click="_ApplyButton_Click" IsEnabled="{Binding IsDirty}" />
        <Button Content="Reset" Height="23" HorizontalAlignment="Right" Margin="0,0,12,12" Name="_ResetButton" VerticalAlignment="Bottom" Width="75" Click="_ResetButton_Click" IsEnabled="{Binding IsDirty}" />

    </Grid>
</UserControl>

My problem is that if I don't use a CellTemplate each cell correctly renders a StatisticCell.ToString() however when I bind, my BindingContext is always the dynamic row instead of the cell.  For example an error in binding from above would be:

System.Windows.Data Error: BindingExpression path error: 'Value' property not found on 'DynamicObjectBuilder_a6f7b2a9-102e-4099-8aed-f404f55b601a' 'DynamicObjectBuilder_a6f7b2a9-102e-4099-8aed-f404f55b601a' (HashCode=18537444). BindingExpression: Path='Value' DataItem='DynamicObjectBuilder_a6f7b2a9-102e-4099-8aed-f404f55b601a' (HashCode=18537444); target element is 'System.Windows.Controls.TextBlock' (Name=''); target property is 'Text' (type 'System.String')..

How can I get the binding context to be the cell instead of the row?  I had the exact same problem when I attempted to use the DictionaryConverter class provided in another thread.  I assume I'm using either the wrong template or misunderstand how to index into the cell within the binding.  Help!

[Vlad]

Hello,

 It will be better if you construct your cell template dynamically and provide binding for valid property or you can use our template selectors. 

Best wishes,
Vlad
the Telerik team

[Noah]

Vlad, I have read the thread you linked before.  Can you explain to me why when no CellTemplate is used, the individual class instance (StatisticCell) is properly rendered in each cell via StatisticCell.ToString() but when the Template is used, the ROW is the binding context.  Is there a way to do something like {Binding Cell.Value}?

[Vlad]

Hi,

 DataContext for all cells and the row itself is the data item. You can check also standard MS DataGrid - the behavior is exactly the same. You can do this (Binding to Cell.Value) however the solution is not trivial in Silverlight (unlike WPF) - you can check it here. Look for CellValueBindingBehavior.

Kind regards,
Vlad
the Telerik team

[John]

Of course now you can use a relative ancestor.  To get the value of the cell (post datamemberbinding) use a relative source to find the cell and bind to it's Value property

<DataTemplate x:Key="DataFlaggedCellTemplate">
 	<Border Background="Aqua">
		<TextBlock Text="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=telerik:GridViewCell, AncestorLevel=1}, Path=Value}" />
	</Border>
</DataTemplate>

[Leah]

John,
Thank you very much for posting your update (two years after the fact!).
It has made all the difference to us.
Leah