how to set focus to a textbox - wpf

Question

I have a windows with this controls.
<Grid>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
///elemnts in row 0
<StackPanel Grid.Row="1">
<ToolBar x:Name="Toolbar">
<Label Content="TextPattern" />
<ComboBox></ComboBox>
<Button Command="{Binding ScanCommand}">
<Image Source="/Images/sacn.png"></Image>
</Button>
<Button Command="{Binding FaxCommand}" x:Name="FaxButton" PreviewKeyDown="FaxButton_PreviewKeyDown">
<Image Source="/Images/fax.png"></Image>
</Button>
</ToolBar>
<TextBox Width="{Binding ElementName=Toolbar,Path=ActualWidth}" x:Name="BodyTextBox" Focusable="True" TextWrapping="Wrap" AcceptsReturn="True" Text="{Binding Body}"></TextBox>
</StackPanel>
<StackPanel Orientation="Horizontal" Grid.Row="2" >
<Button Content="Save" Command="{Binding SaveCommand}"></Button>
<Button Content="Cancel" Command="{Binding CancelCommand}"></Button>
</StackPanel>
</Grid>
When i use tab key for get focus, it go to savebutton after press tab of faxbutton. But i want to go to BodyTextbox.
I use PreviewKeyDown for set focus.
private void FaxButton_PreviewKeyDown(object sender, KeyEventArgs e)
{
if(e.Key==Key.Tab)
{
BodyTextBox.Focus();
BodyTextBox.SelectAll();
FocusManager.SetFocusedElement(this, BodyTextBox);
}
}
But don't set Focus.

Answer 1

When you load UserControl or Windowcontrol:
Please write this in the UserCOntrol_Load Event:
Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.Input,
new Action(delegate ()
{
BodyTextBox.Focus(); // Set Logical Focus
Keyboard.Focus(BodyTextBox); // Set Keyboard Focus
}));
it will be automatically focus n also u can write content from keyboard without any tab pressing..
Hope this will work for U..
Thanks,
Praveen

Answer 2

Remove the PreviewKeyDown event and Add KeyboardNavigation.TabNavigation="Continue" in tool bar
<ToolBar x:Name="Toolbar" KeyboardNavigation.TabNavigation="Continue">