RadListBox allows you to navigate between the items using the arrow keys on the keyboard. To enable this, you will need to select any item in order to focus the control. Using touch input to select an item, instead of the mouse, is breaking the arrow keys navigation. Pressing up and down no longer navigates to the previous and next item.

To work this around, subscribe the RadListBox control to the TouchManager.Tap event and focus the tapped RadListBoxItem in the event handler.

public MainWindow()
{
	InitializeComponent();
	TouchManager.AddTapEventHandler(this.listBox, this.OnTap, true);
}

private void OnTap(object sender, TapEventArgs e)
{
	var tapElement = (FrameworkElement)e.OriginalSource;
	var item = tapElement.ParentOfType<RadListBoxItem>();
	if (item != null)
	{
		item.Focus();
	}
}