Background:
Setting DockMode for specific C1DockTabItems can be achieved by setting the property of the parent.
Steps to Complete:
private void Button_Click(object sender, RoutedEventArgs e) { var parent = tab1.Parent as C1DockTabControl; if (parent != null) { if (parent.Items.Count == 1) { parent.DockMode = DockMode.Sliding; } else { parent.Items.Remove(tab1); C1DockTabControl newDockTabCtrl = new C1DockTabControl(); c1DockTabControl.Items.Add(newDockTabCtrl); newDockTabCtrl.Items.Add(tab1); newDockTabCtrl.DockMode = DockMode.Sliding: } } }