System.Object
   System.EventArgs
      System.ComponentModel.CancelEventArgs
         Xceed.Wpf.Controls.AutoCompletingMaskEventArgs
      System.Windows.RoutedEventArgs
         Xceed.Wpf.Controls.QueryMoveFocusEventArgs
      Xceed.Wpf.Controls.QueryTextFromValueEventArgs
      Xceed.Wpf.Controls.QueryValueFromTextEventArgs
   System.Windows.Threading.DispatcherObject
      System.Windows.DependencyObject
         System.Windows.Media.Visual
            System.Windows.UIElement
               System.Windows.FrameworkElement
                  System.Windows.Controls.Control
                     System.Windows.Controls.ContentControl
                        Xceed.Wpf.Controls.CheckBox
                     System.Windows.Controls.ItemsControl
                        System.Windows.Controls.Primitives.Selector
                           System.Windows.Controls.ComboBox
                              Xceed.Wpf.Controls.NavigableComboBox
                     System.Windows.Controls.Primitives.TextBoxBase
                        System.Windows.Controls.TextBox
                           Xceed.Wpf.Controls.AutoSelectTextBox
                              Xceed.Wpf.Controls.ValueRangeTextBox
                                 Xceed.Wpf.Controls.MaskedTextBox
                                    Xceed.Wpf.Controls.DateTimeTextBox
                                 Xceed.Wpf.Controls.NumericTextBox
                              Xceed.Wpf.Controls.WatermarkTextBox
                     Xceed.Wpf.Controls.DatePicker
                  System.Windows.Controls.Decorator
                     Xceed.Wpf.Controls.DateInputScope
                     Xceed.Wpf.Controls.NumericInputScope
                  System.Windows.Controls.Panel
                     Xceed.Wpf.Controls.DateLayoutPanel
                  Xceed.Wpf.Controls.TextBlockLite
         Xceed.Wpf.Controls.CalendarItem
   Xceed.Wpf.Controls.DatePickerCommands
   Xceed.Wpf.Controls.Licenser

Reference

Xceed.Wpf.Controls Assembly