Set focus on textbox in WPF

Question

In XAML:

<StackPanel FocusManager.FocusedElement="{Binding ElementName=Box}">
   <TextBox Name="Box" />
</StackPanel>

Nobody explained so far why the code in the question doesn't work. My guess is that the code was placed in the constructor of the Window. But at this time it's too early to set the focus. It has to be done once the Window is ready for interaction. The best place for the code is the Loaded event:

public KonsoleWindow() {
  public TestWindow() {
    InitializeComponent();
    Loaded += TestWindow_Loaded;
  }

  private void TestWindow_Loaded(object sender, RoutedEventArgs e) {
    txtCompanyID.Focus();
  }
}

try FocusManager.SetFocusedElement

FocusManager.SetFocusedElement(parentElement, txtCompanyID)

txtCompanyID.Focusable = true;
Keyboard.Focus(txtCompanyID);

msdn:

There can be only one element on the whole desktop that has keyboard focus. In WPF, the element that has keyboard focus will have IsKeyboardFocused set to true.

You could break after the setting line and check the value of IsKeyboardFocused property. Also check if you really reach that line or maybe you set some other element to get focus after that.

Try this : MyTextBox.Focus ( );

None of this worked for me as I was using a grid rather than a StackPanel.

I finally found this example: http://spin.atomicobject.com/2013/03/06/xaml-wpf-textbox-focus/

and modified it to this:

In the 'Resources' section:

    <Style x:Key="FocusTextBox" TargetType="Grid">
        <Style.Triggers>
            <DataTrigger Binding="{Binding ElementName=textBoxName, Path=IsVisible}" Value="True">
                <Setter Property="FocusManager.FocusedElement" Value="{Binding ElementName=textBoxName}"/>
            </DataTrigger>
        </Style.Triggers>
    </Style>

In my grid definition:

<Grid Style="{StaticResource FocusTextBox}" />

In case you haven't found the solution on the other answers, that's how I solved the issue.

Application.Current.Dispatcher.BeginInvoke(new Action(() =>
{
    TEXTBOX_OBJECT.Focus();
}), System.Windows.Threading.DispatcherPriority.Render);

From what I understand the other solutions may not work because the call to Focus() is invoked before the application has rendered the other components.