Appendix D. WPF Base Types
WPF defines a large number of types, forming an extensive class hierarchy. This appendix describes the roles of the most important types. It does not provide a detailed description of each type—the MSDN documentation already does that. Instead, this is a high-level guide offering a broad view of how the various types fit together. Figure D-1 shows the inheritance relationships among the types described in this appendix.
DispatcherObject is the base
class of any type associated with a
Dispatcher. The dispatcher mechanism is WPF’s
message processing system. It underpins critical services including
input handling, and certain aspects of layout and data binding. It is
also at the heart of the WPF threading model. Threading and the
dispatcher system are described in Appendix C.
All of the base types examined in this appendix derive from
DispatcherObject, reflecting the
dispatcher’s central role. Although
DispatcherObject is the most common base class
in WPF, few classes derive from it directly. Most derive indirectly via
System.Object System.Windows.Threading.DispatcherObject System.Windows.DependencyObject
Classes derive from
DependencyObject to employ WPF’s dependency property (DP) system. The majority of WPF element ...