Disable tabstop between columns in a WPF datagrid

Question

I have a WPF Toolkit datagrid with mulitple columns. I am trying to get a behaviour where you can tab into the grid using tab, then tab out again using a single tab. E.g. I do not want to tab through all the columns or cells of the grid, just once in, and once out.

Is there a simple solution, I have tried setting the TabNavigation to Once, along with disabling TabStop (not shown in code below) and setting TabNavigation on the columns to None, but without success.

Is there something I am missing or do I need to handle the Tab-key in code?

        <my:DataGrid Name="datagrid"
                     AutoGenerateColumns="False" IsReadOnly="True"
                     CanUserAddRows="False" CanUserDeleteRows="False"
                     Background="White"
                     KeyboardNavigation.TabNavigation="Once">
            <my:DataGrid.Columns>
                <my:DataGridTextColumn x:Name="ID" Header="ID" Width="1*" ></my:DataGridTextColumn>
                <my:DataGridTextColumn x:Name="Ticker" Header="Ticker" Width="1*" KeyboardNavigation.TabNavigation="None"></my:DataGridTextColumn>
                <my:DataGridTextColumn x:Name="OfficialName" Header="Name" Width="3*" KeyboardNavigation.TabNavigation="None"></my:DataGridTextColumn>
            </my:DataGrid.Columns>
        </my:DataGrid>

Answer 1

It's interesting that setting the KeyboardNavigation directly on the DataGridTextColumn's doesn't work. An alternative that should work is to set up a DataGridCell style.

<toolkit:DataGrid.CellStyle>
    <Style TargetType="{x:Type toolkit:DataGridCell}">
        <Setter Property="KeyboardNavigation.IsTabStop"
                Value="False" />
        <Style.Triggers>
            <Trigger Property="IsSelected"
                     Value="True">
                <Setter Property="KeyboardNavigation.IsTabStop"
                        Value="True" />
            </Trigger>
        </Style.Triggers>
    </Style>
</toolkit:DataGrid.CellStyle>

Attaching this to the DataGrid will ensure that a cell is only a TabStop if it is already selected. However, if you are selecting full rows and don't have SelectionUnit="Cell" set on the DataGrid, it will still cycle through each column of the currently selected row.

Instead, we can create multiple CellStyles as resources within the DataGrid:

<toolkit:DataGrid.Resources>

    <Style  x:Key="SelectableCellStyle"
            TargetType="{x:Type toolkit:DataGridCell}">
        <Setter Property="KeyboardNavigation.IsTabStop"
                Value="False" />
        <Style.Triggers>
            <Trigger Property="IsSelected"
                     Value="True">
                <Setter Property="KeyboardNavigation.IsTabStop"
                        Value="True" />
            </Trigger>
        </Style.Triggers>
    </Style>

    <Style TargetType="{x:Type toolkit:DataGridCell}">
        <Setter Property="KeyboardNavigation.IsTabStop"
                Value="False" />
    </Style>

</toolkit:DataGrid.Resources>

Now we have a style being applied to all DataGridCells by default and turning off TabStop, and a keyed style that allows selection when the Cell (or whole Row) is selected. Applying this style to only a single column will give us the same single-tab-in effect while allowing the whole row and all of it's columns to be selected.

 <my:DataGridTextColumn x:Name="ID" Header="ID" Width="1*" CellStyle={StaticResource  SelectableCellStyle}"/>

This does also stop tabbing into the DataGrid if nothing is selected, which may be preferred or not depending on the situation you are using it in.

Answer 2

Thank you rmoore. To get the tab stop to be disabled for columns I took your answer and modified it slightly;

     <my:DataGrid Name="datagrid" 
                 AutoGenerateColumns="False" IsReadOnly="True" 
                 CanUserAddRows="False" CanUserDeleteRows="False" 
                 Background="White" 
                 KeyboardNavigation.TabNavigation="Once"
                 SelectionUnit="FullRow"> 
        <my:DataGrid.Columns> 
            <my:DataGridTextColumn x:Name="ID" Header="ID" Width="1*" ></my:DataGridTextColumn> 
            <my:DataGridTextColumn x:Name="Ticker" Header="Ticker" Width="1*">
                    <my:DataGridTextColumn.CellStyle>
                        <Style TargetType="{x:Type my:DataGridCell}">
                            <Setter Property="KeyboardNavigation.IsTabStop" Value="False"></Setter>
                        </Style>
                    </my:DataGridTextColumn.CellStyle>
            </my:DataGridTextColumn> 

            <my:DataGridTextColumn x:Name="OfficialName" Header="Name" Width="3*">
                  <my:DataGridTextColumn.CellStyle>
                        <Style TargetType="{x:Type my:DataGridCell}">
                            <Setter Property="KeyboardNavigation.IsTabStop" Value="False"></Setter>
                        </Style>
                  </my:DataGridTextColumn.CellStyle>
            </my:DataGridTextColumn> 
        </my:DataGrid.Columns> 
    </my:DataGrid>

So tricks;

1. SelectionUnit="FullRow" makes the GUI look like you are doing things one row at a time (like I wanted).
2. By adding a CellStyle to the columns I want to disable TabStop in (but not including it in those I would like to stop in) allowed me to take control over which cells that tab-key would navigate into. - The KeyboardNavigation.TabNavigation not having an effect when defined on columns.