Question

I have WPF DataGrid placed on the Window. I have a button which performs some business logic and populates the grid.

I want to set focus on the DataGrid (preferably first row in the DataGrid) when i TAB from the button. I have set the TabIndex but somehow the focus does not come on the DataGrid.

The relevant part of the form’s XAML is here:

<StackPanel Orientation="Vertical" Grid.Column="2" Margin="20,10,10,10">
    <Button Content="Search"
                Height="25" HorizontalAlignment="Right" Margin="0,-25,0,0"
                Name="btnSearch" VerticalAlignment="Top" Width="75" **TabIndex="1300"** Click="btnSearch_Click" Keyboard.KeyDown="btnSearch_PreviewKeyDown" LostFocus="btnSearch_LostFocus"/>
</StackPanel>
<DataGrid AutoGenerateColumns="False" Grid.Column="1" Margin="20,160,10,10" Name="dataGridOrganisations" **TabIndex="1400"**
          BorderThickness="2" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Focusable="True"
                ScrollViewer.VerticalScrollBarVisibility="Auto" ScrollViewer.HorizontalScrollBarVisibility="Auto" GridLinesVisibility="None"
           ItemsSource="{Binding}" CanUserReorderColumns="False" CanUserResizeRows="False" IsReadOnly="True" SelectionChanged="dataGridOrganisations_SelectionChanged" Keyboard.PreviewKeyDown="dataGridOrganisations_PreviewKeyDown"  >
    <DataGrid.Columns>
        <DataGridTextColumn Header="Shortname" Width="100" Binding="{Binding ShortName}" />
        <DataGridTextColumn Header="Internal Code" Width="100" Binding="{Binding LocalID}"/>
        <DataGridTextColumn Header="Name" Width="*" Binding="{Binding Name}"/>
    </DataGrid.Columns>
</DataGrid>

When I added following code on Button’s LostFocus event, it highlights the first row. But when I use ‘down’ arrow key to select next row in the grid; instead of going to next row it first sets focus on the ‘Search’ button and next time goes to second row!

if (this.dataGridOrganisations != null && this.dataGridOrganisations.HasItems)
{
    this.dataGridOrganisations.Focus();
    if (dataGridOrganisations.Items != null && dataGridOrganisations.Items.Count > 0)
    {
        DataGridRow firstRow = this.dataGridOrganisations.ItemContainerGenerator.ContainerFromItem(dataGridOrganisations.Items[0]) as DataGridRow;
        if (firstRow != null)
        {
            firstRow.IsSelected = true;
        }
    }
}

How to set focus on the DataGrid (or its first row)? Why TabIndex does not work here?

Answer 1

You do not even need a tab-index if there are no focusable controls between the Button and DataGrid in the control hierarchy. You have quite a few handlers and everything seems a bit convoluted to me. I cannot spot anything in that code (maybe someone else can of course), my suggestion would be that you try to simplify your code until it works again as it should by default. e.g. this code’s tabbing should work:

  <StackPanel>
    <Button Content="Lorem Ipsum"/>
    <DataGrid ItemsSource="{Binding Source={StaticResource Items}}">
        <DataGrid.Columns>
            <DataGridTextColumn Binding="{Binding Name}"/>
        </DataGrid.Columns>
    </DataGrid>
  </StackPanel>

Also, why the large tab-index delta? If you were to use 1301 & 1302 there could not be any value between so it should automatically be safer code.