Architecture and Class Hierarchy of WPF: Part 2

In my previous article you will learn about WPF Architecture now we talk about Class Hierarchy of WPF.

Class Hierarchy of WPF

Lets see the hierarchy of classes that leads to the basic set of WPF controls.

• System.Threading.DispatcherObject: It provides the basic constructor for dealing with concurrency and threading and most objects in WPF derive from DispatcherObject. WPF is based on a messaging system implemented by the dispatcher.
   

• System.Windows.DependencyObject: The base class for any object that can support dependency properties. DependencyObject defines the GetValue and SetValue methods that are central to the operation of dependency properties.
  

• System.Windows.Media.Visual: It provides the link between managed WPF libraries and milcore.dll that renders display.
  
  Syntax:
  
  'Declaration
  Public MustInherit Class Visual _
  Inherits DependencyObject
   

• System.Windows.UIElement: The base class for all visual objects with support for routed events, command binding, layout, and focus.
  
  Syntax:
  
  'Declaration
  <UidPropertyAttribute("Uid")> _
  Public Class UIElement _
  Inherits Visual _
  Implements IAnimatable, IInputElement
  

• System.Windows.FrameworkElement: FrameworkElement can be looked at in two different ways. It introduces a set of policies and customizations on the subsystems introduced in lower layers of WPF. It also introduces a set of new subsystems.
  
  Syntax:
  
  'Declaration
  <StyleTypedPropertyAttribute(Property := "VisualStyle", StyleTargetType := GetType(Control))> _
  <RuntimeNamePropertyAttribute("Name")> _
  <XmlLangPropertyAttribute("Language")> _
  <UsableDuringInitializationAttribute(True)> _
  Public Class FrameworkElement _
  Inherits UIElement _
  Implements IFrameworkInputElement, IInputElement, ISupportInitialize, IQueryAmbient
  

• System.Windows.Controls.Control: It is an element that can interact with a user. It provides template control which allows the user to replace the standard appearance of a control with a custom appearance.
  
  Syntax:
  
  'Declaration
  Public Class Control _
  Inherits FrameworkElement

Conclusion

Hope this article would have helped you in understanding WPF Architecture and Class Hierarchy concept.