Moving to next control on Enter keypress in WPF

Below is an attached property that I’ve used for just this.

First, example usage:

<TextBox Width="100"
         Text="{Binding Name, Mode=TwoWay}"
         UI:FocusAdvancement.AdvancesByEnterKey="True" />

(UI is the namespace alias for where I’ve defined the following.)

The attached property:

public static class FocusAdvancement
{
    public static bool GetAdvancesByEnterKey(DependencyObject obj)
    {
        return (bool)obj.GetValue(AdvancesByEnterKeyProperty);
    }

    public static void SetAdvancesByEnterKey(DependencyObject obj, bool value)
    {
        obj.SetValue(AdvancesByEnterKeyProperty, value);
    }

    public static readonly DependencyProperty AdvancesByEnterKeyProperty =
        DependencyProperty.RegisterAttached("AdvancesByEnterKey", typeof(bool), typeof(FocusAdvancement), 
        new UIPropertyMetadata(OnAdvancesByEnterKeyPropertyChanged));

    static void OnAdvancesByEnterKeyPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var element = d as UIElement;
        if(element == null) return;

        if ((bool)e.NewValue) element.KeyDown += Keydown;
        else element.KeyDown -= Keydown;
    }

    static void Keydown(object sender, KeyEventArgs e)
    {
        if(!e.Key.Equals(Key.Enter)) return;

        var element = sender as UIElement;
        if(element != null) element.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
    }
}

You also said “instead of tab,” so I’m wondering if you want to suppress the ability to use tab in the usual way. I’d advise against it, as it is a common, well known paradigm, but if that is the case, you can add a PreviewKeyDown handler in the attached property, check for the tab key, and set Handled = true for the event args.