Datagrid combobox column populated with values from another column in the same datagrid

Question

I have a DataGrid bound to a List<Coefficients> in memory. The Coefficients class has a string Name as ID, and a lot of other fields (some names and identifying details have been changed to protect the privacy of the code). The DataGrid code is like this:

<DataGrid
    Name="coefficientList"
    ItemsSource="{Binding Data.CoefficientList, Mode=TwoWay}">
    <DataGrid.Columns>
        <DataGridTextColumn Binding="{Binding Path=Name, Mode=TwoWay}" />
        <DataGridTextColumn Binding="{Binding Path=Priority, Mode=TwoWay}" />
        ...
    </DataGrid.Columns>
</DataGrid>

Now the elements in the datagrid must reference another element in the same collection, so I have a new field in the Coefficients class: string ReferencedName . This is the string ID of the referenced element in the collection. So I would like to have a new column in the datagrid to select the value of the referenced element via a combobox, and that combobox needs to be populated with the Name column of the same datagrid.

How can I achieve that? So far I have tried something like:

<DataGridTemplateColumn>
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <ComboBox
                SelectedValue="{Binding ReferencedName, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}},
                    Path=Data.NameList, Mode=TwoWay}" />
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

where NameList is

public IEnumerable<string> NameList
{
    get
    {
        return CoefficientList.Select(c => c.Name);
    }
}

but anything I have tried so far always gives a combobox with no options, and errors in the output window like

System.Windows.Data Error: 40 : BindingExpression path error: 'Data' property not found on 'object' ''DataGrid' (Name='coefficientList')'. BindingExpression:Path=Data.NameList; DataItem='DataGrid' (Name='coefficientList'); target element is 'ComboBox' (Name=''); target property is 'ItemsSource' (type 'IEnumerable')

Can anyone point me in the right direction?

Answer 1

Data.NameList is a property of DataContext object. change binding path

Path=DataContext.Data.NameList