Default focus in XAML

Very simple task, you open window and you want some text box to have focus. And since it's common and simple task I thought it should be possible using XAML. To do this, you should use FocusManager. However, you should pay attention where you put it. I had to use it right in the Grid where I placed my TextBox. Which is logical, if you think about it. How else TextBox can be found.

Here is the xaml:

<UserControl x:Class="Actsoft.CometTracker.Layouts.AddViewView"
             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" 
             mc:Ignorable="d" 
             d:DesignHeight="40" d:DesignWidth="300"
             >
    <Grid
        FocusManager.FocusedElement="{Binding ElementName=textBox}">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto"/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>
        <Label 
            Margin="4">View Name:</Label>
        <TextBox Grid.Column="1" x:Name="textBox"
            Margin="4" Text="{Binding Path=ViewName}"/>
    </Grid>
</UserControl>