DataGridTemplateColumn.CellEditingTemplate converting a TextBox to Combobox inconsistent

Question

I have the following XAML code:

<DataGrid ItemsSource="{Binding TempParameters}" AutoGenerateColumns="False" CanUserAddRows="False" Height="100" Name="TempParameterGrid" CanUserSortColumns="False" Width="{Binding Source={StaticResource theWidth}}" MouseDown="SetSelectedGrid">
     <DataGrid.Columns>
         <DataGridTextColumn Width="*" Header="ID"  IsReadOnly="True" Binding="{Binding ID}"/>
         <DataGridTemplateColumn Header="Parameter" IsReadOnly="False" >
             <DataGridTemplateColumn.CellEditingTemplate>
                 <DataTemplate>
                     <ComboBox SelectedValue="{Binding name, Mode=TwoWay}" ItemsSource ="{Binding ParameterNames, RelativeSource={RelativeSource AncestorType={x:Type Window}}}" />
                 </DataTemplate>
             </DataGridTemplateColumn.CellEditingTemplate>
             <DataGridTemplateColumn.CellTemplate>
                 <DataTemplate>
                     <TextBox Text ="{Binding name, Mode=TwoWay}" />
                 </DataTemplate>
             </DataGridTemplateColumn.CellTemplate> 
         </DataGridTemplateColumn>
         <DataGridTextColumn Width="*" Header="Start"      IsReadOnly="False" Binding="{Binding start}"/>
         <DataGridTextColumn Width="*" Header="End"        IsReadOnly="False" Binding="{Binding end}"/>
         <DataGridTextColumn Width="*" Header="Samples"    IsReadOnly="False" Binding="{Binding samples}"/>
     </DataGrid.Columns>
 </DataGrid>

The DataGrid binds to a collection property TempParameters. This is a collection of the following objects.

    public class TuneParameterRecord {
        public int ID { get; set; }
        public string name { get; set; }
        public double start { get; set; }
        public double end { get; set; }
        public int samples { get; set; }
    }

All the columns are editable. However I need the name column to have a list of predefined names. Therefore I was thinking to provide a ComboBox with a list of acceptable values (while many will point it out, this list cannot be an enum. I need this to be a list of strings). This list is provided in the window data context.

I can reference it directly providing a relative source in the CellEditingTemplate. My problem is that when i try to edit a cell in the column in question, I get a cursor that can edit the textbox instead of getting a combobox.

In order to get the combobox. I have to click multiple times in the area indicated with red in the attached pictures. The first picture shows the cell being editable with a cursor, while the second image has the combobox (though masked) after I have clicked multiple times in the red area indicated.

Answer 1

So I have found the problem. I have converted the

<DataGridTemplateColumn.CellTemplate>
     <DataTemplate>
         <TextBox Text ="{Binding name, Mode=TwoWay}" />
     </DataTemplate>
</DataGridTemplateColumn.CellTemplate>

to

<DataGridTemplateColumn.CellTemplate>
     <DataTemplate>
         <TextBlock Text ="{Binding name, Mode=TwoWay}" />
     </DataTemplate>
</DataGridTemplateColumn.CellTemplate>

This defaults to the desired behavior. I have a feeling that I got the inconsistent behavior because the TextBox can be edited while the Textblock cannot. Therefore a single click would select the TextBox but not revert to the cell editing template.