WPF DataGrid: DataGridComboxBox ItemsSource Binding to a Collection of Collections

Situation:

I've created a DataGrid in XAML and the ItemsSource is binded to an ObservableCollection of a certain class that contains properties. Then in C#, I create a DataGridTextColumn and a DataGridComboBoxColumn and binded these to the properties of the objects inside the ObservableCollection. I can bind the DataGridComboBoxColumn to a simple Collection but what I want to do is bind it to a collection of collections of strings so that for each row the ComboBox inside the DataGrid has a different collection of string. I have failed to do so...

Question:

How can I bind the DataGridCombBoxColumn so that I can have a different collection of strings for each row of this type of column?

Code Sample:

XAML:

<Window>
  <!-- ... -->
  WPFToolkit:DataGrid
           x:Name="DG_Operations"
           Margin="10,5,10,5" 
           Height="100" 
           HorizontalAlignment="Stretch" 
           FontWeight="Normal" 
           ItemsSource="{Binding Path=OperationsStats}"
           AlternatingRowBackground="{DynamicResource SpecialColor}" 
           HorizontalScrollBarVisibility="Auto" 
           VerticalScrollBarVisibility="Visible" 
           SelectionMode="Extended"
           CanUserAddRows="False" 
           CanUserDeleteRows="False"
           CanUserResizeRows="True" 
           CanUserSortColumns="True"
           AutoGenerateColumns="False" 
           IsReadOnly="False" 
           IsEnabled="True"
           BorderThickness="1,1,1,1" 
           VerticalAlignment="Stretch"/>
  <!-- ... -->
</Window>

C#:

public class DataModelStatsOperations
{
   public ObservableCollection<IStatsOperation> OperationsStats { get; set; }
}

public interface IStatsOperation
{
   string Operation { get; set; }
   Collection<string> Data{ get; set; }
}

public class StatsOperation : IStatsOperation
{
    public StatsOperation(string operation, Collection<string> data)
    {
        Operation = operation;
        Data = data;
    }
    public string Operation { get; set; }
    public Collection<string> Data{ get; set; }
}

private ObservableCollection<IStatsOperation> dataOperations_ =
        new ObservableCollection<IStatsOperation>();

//...
 Binding items = new Binding();
 PropertyPath path = new PropertyPath("Operation");
 items.Path = path;
 DG_Operations.Columns.Add(new DataGridTextColumn()
 {
     Header = "Operations",
     Width = 133,
     Binding = items
  });
  DG_Operations.Columns.Add(new DataGridComboBoxColumn()
  {
     Header = "Data",
     Width = 190,
     ItemsSource = /*???*/,
     SelectedValueBinding = new Binding("Data"),
     TextBinding = new Binding("Data")
  });
dataOperations_.Add(new StatsOperation(CB_Operation.SelectedItem.ToString(),
                                                           dataCollection));
DG_Operations.DataContext = new DataModelStatsOperations
{
    OperationsStats = dataOperations_
};
//...

Any help would be greatly appreciated!

Notes:

Okay, so after reading the two first answers I noticed something. My binding is really not right! Now, what I want to do is something similar to what AndyG proposed:

DG_Operations.Columns.Add(new DataGridComboBoxColumn()
{
    Header = "Data",
    Width = 190,
    ItemsSource = new Binding("Data"), //notice this here does not work (have a look at the following error)
    SelectedValueBinding = new Binding("Operation"),
    TextBinding = new Binding("Operation")
});

Error: "Cannot implicitly convert type 'System.Windows.Data.Binding' to 'System.Collections.IEnumerable'."

How can the ItemsSource be bound to Data?

Firstly, this should be easy... secondly, why are you building (and binding) columns in C#? Eek.

XAML (I'm using a regular grid because I'm lazy):

<ListView Name="MyListView">
    <ListView.View>
        <GridView>

            <GridView.Columns>

                <GridViewColumn DisplayMemberBinding="{Binding Operation}" />

                <GridViewColumn>
                    <GridViewColumn.CellTemplate>
                        <DataTemplate>
                            <ComboBox ItemsSource="{Binding Choices}" />
                        </DataTemplate>
                    </GridViewColumn.CellTemplate>
                </GridViewColumn>

            </GridView.Columns>

        </GridView>
    </ListView.View>
</ListView>

C#:

void Window1_Loaded(object sender, RoutedEventArgs e)
{
    var dahList = new List<StatsOperation>();

    dahList.Add(new StatsOperation
    {
        Operation = "Op A",
        Choices = new string[] { "One", "Two", "Three" },
    });

    dahList.Add(new StatsOperation
    {
        Operation = "Op B",
        Choices = new string[] { "4", "5", "6" },
    });

    this.MyListView.ItemsSource = dahList;
}

The Results:

WPF grid with dynamic combo box choices http://www.singingeels.com/Articles/Articles/UserImage.aspx?ImageID=b1e3f880-c278-4d2b-bcc2-8ad390591200

I think the mistake is in how you've done your binding. When you define a column, the binding is related to the object that is represented by a particular row. So as I understand, you have a StatsOperation for each row, so the TextBox column is bound to operation, which is how you have it, and the ComboBox column ItemsSource should be bound to a Collection. Right now it looks like it's bound to a Collection<Collection<string>>.

I've not defined columns in code-behind before so here is an example in XAML. I've found ComboBoxColumn can be tricky sometimes so i've shown how you can have a combobox in the column by using either a TemplateColumn or a ComboBoxColumn. I've copy pasted from my own code so just replace 'dg' with 'WPFToolkit' in your case:

<dg:DataGrid
      ...
      ...>
      <dg:DataGrid.Columns>
            <dg:DataGridTextColumn Binding="{Binding Operation}" CanUserReorder="True" CanUserResize="True" Header="Operation" />
            <dg:DataGridTemplateColumn CanUserReorder="True" CanUserResize="True" Header="Template Column">
                <dg:DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <ComboBox ItemsSource="{Binding Data}" SelectedItem="{Binding Operation}" />
                    </DataTemplate>
                </dg:DataGridTemplateColumn.CellTemplate>
            </dg:DataGridTemplateColumn>
            <dg:DataGridComboBoxColumn
                Header="ComboBox Column"                                                                                    
                 SelectedValueBinding="{Binding Operation}"                     
                 SelectedItemBinding="{Binding Operation}">
                <dg:DataGridComboBoxColumn.ElementStyle>
                    <Style TargetType="ComboBox">
                        <Setter Property="IsSynchronizedWithCurrentItem" Value="False" />
                        <Setter Property="ItemsSource" Value="{Binding Data}" />
                    </Style>
                </dg:DataGridComboBoxColumn.ElementStyle>
                <dg:DataGridComboBoxColumn.EditingElementStyle>
                    <Style TargetType="ComboBox">
                        <Setter Property="ItemsSource" Value="{Binding Data}" />
                        <Setter Property="IsDropDownOpen" Value="True" />
                    </Style>
                </dg:DataGridComboBoxColumn.EditingElementStyle>
            </dg:DataGridComboBoxColumn>
      </dg:DataGrid.Columns>

</dg:DataGrid>

I'm assuming that Operation is the selected item, Data is the items to select from, and that your DataGrid is bound to a collection of StatsOperation. Good luck!

To fix your ItemsSource Binding Error use the form:

BindingOperations.SetBinding(new DataGridComboBoxColumn(), DataGridComboBoxColumn.ItemsSourceProperty, new Binding("Data"));

You obviously can't do this in the intializer so you'll have to move your declarations around a bit but that should take care of that error in your update.