Keyboard Focus navigation problem with ElementHost hosted WPF view with WindowsFormsHost hosted controls

Question

I have a keyboard focus problem with Windows Forms application that hosts WPF UserControls. When I press tab, the navigation works well if there are only WPF controls in the UserControl. If I add a WindowsFormsHost hosted control to this WPF UserControl, the focus is not moving away from the WindowsFormsHosted control in WPF UserControl.

When the application is WPF application, the focus navigation works perfectly but when I add this WPF UserControl to Windows Forms application, pressing TAB doesn't work anymore.

It would be great to get some help with this.

Here is my code:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        ElementHost host = new ElementHost();
        host.Dock = DockStyle.Fill;
        host.Child = new SomeControls();
        this.Controls.Add(host);
    }
}

/// <summary>
/// Interaction logic for SomeControls.xaml
/// </summary>
public partial class SomeControls : UserControl
{
    public SomeControls()
    {
        InitializeComponent();
    }
}

<UserControl x:Class="TabAndHostTest.SomeControls"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         xmlns:forms="clr-namespace:System.Windows.Forms;assembly=System.Windows.Forms"
         xmlns:my="clr-namespace:TabAndHostTest" Width="450">
<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="124*" />
        <ColumnDefinition Width="388*" />
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
    </Grid.RowDefinitions>

    <Label Grid.Row="0" Grid.Column="0" Content="value1" Height="28" HorizontalAlignment="Left" Name="value1" VerticalAlignment="Top" />
    <TextBox Grid.Row="0" Grid.Column="1" Height="23" HorizontalAlignment="Left" Name="textBox1" VerticalAlignment="Top" Width="257" />

    <Label Grid.Row="1" Content="value2" Height="28" HorizontalAlignment="Left" Name="value2" VerticalAlignment="Top" />
    <TextBox Grid.Row="1" Grid.Column="1" Height="23" HorizontalAlignment="Left" Name="textBox2" VerticalAlignment="Top" Width="257" />

    <Label Grid.Row="2" Grid.Column="0" Content="hostedvalue1" Height="28" HorizontalAlignment="Left" Name="hostedvalue1" VerticalAlignment="Top" />
    <WindowsFormsHost Grid.Column="1" Grid.Row="2" Height="23" HorizontalAlignment="Left" Name="windowsFormsHost1" VerticalAlignment="Top" Width="307">
        <forms:TextBox x:Name="formsTextbox1" Height="23" Width="150" />
    </WindowsFormsHost>

    <Label Grid.Row="3" Grid.Column="0" Content="hostedvalue2" Height="28" HorizontalAlignment="Left" Name="hostedvalue2" VerticalAlignment="Top" />
    <WindowsFormsHost Grid.Column="1" Grid.Row="3" Height="23" HorizontalAlignment="Left" Name="windowsFormsHost2" VerticalAlignment="Top" Width="307">
        <forms:TextBox x:Name="formsupdown1" Height="23" Width="150" />
    </WindowsFormsHost>
</Grid>

Answer 1

Thank you for Mark Staff of the knowledge about focusing. The problem was really fixed with OnNoMoreTabStops method. I posted this problem to MSDN forum too and they found the solution for my problem. Here is the link to MSDN forums thread: http://social.msdn.microsoft.com/Forums/en-ZA/wpf/thread/054d8509-dd2d-4b60-9b0a-383b0147e2ac