WPF provides access to 2D and 3D graphics, controls, and rich document viewing with a consistent programming model. It uses hardware acceleration for improved visual rendering. Key benefits include broad integration, resolution independence, and declarative programming using XAML. The core WPF assemblies include PresentationFramework, PresentationCore, and WindowsBase. The Application class manages the lifetime of a WPF application, while the Window class represents individual windows. Controls such as buttons, text boxes, and containers are used to build the user interface.

1. WPF Deep DiveAniruddha ChakrabartiSr. Solution Architect“If I have six hours to chop down a tree, I will use four hours to sharpen the axe” – Abraham Lincoln

2. Key benefits of WPFBroad integrationProvides access to normal 2D graphics, controls, 3D, video, speech and rich document viewing with consistent programming model as well as tight integrationHardware accelerationImproved Visual RenderingRetained mode graphicsVector graphicsResolution independence (Device Independent Graphics)Declarative programming (aka XAML)Rich composition, layout and customizationEasy deploymentIncorporates best of Web and WindowsIntegrate developers and designers

3. WPF Architecture

4. WPF Architecture

5. WPF: Assemblies and NamespacesPrimary Assemblies containing the WPF APIPresentationFrameworkPresentationCoreWindowsBasemilcore (unmanaged)mil: Media Integration LayerNamespacesSystem.WindowsOther child namespaces starting with System.Windows except System.Windows.Forms (Win Forms)System.Windows.ControlsSystem.Windows.DataSystem.Windows.DocumentsSystem.Windows.Media (+ child namespaces)System.Windows.ShapesManagedUnmanaged/Native

6. WPF Base Class HierarchyWindowsBasePresentationFrameworkPresentationCore

7. WPF Base Class DetailsSystem.Threading.DispatcherObject:

8. Provides basic constructs for dealing with concurrency and threading. WPF is based on a messaging system implemented by the dispatcher - works much like familiar Win32 message pump

9. System.Windows.DependencyObject:

10. Provides reach Property System (DP + attached property)

11. System.Windows.Media.Visual:

12. Provides for building a tree of visual objects. Visual is designed to be extremely lightweight and flexible, so most of the features have no public API exposure.

13. Visual is really the entry point to the WPF composition system. Visual is the point of connection between these two subsystems, the managed API and the unmanaged milcore.

14. System.Windows.UIElement:

15. defines core subsystems including Layout, Input, and Events

16. System.Windows.FrameworkElement:

17. Provides Advanced Layout on top of the features provided by UIElement

18. Provides DataBinding & Styles

19. System.Windows.Controls.Control:

20. Provides Templating SupportDifferent type of WPF applicationsStandalone/Desktop Applications

21. Window class is used to create windows and dialog boxes

22. Browser Hosted Applications / XAML Browser Applications (XBAP)

23. Create Page, Page Function

24. Loose XAML pages (can be opened in IE)XAML (eXtensibleApplication Markup Language)

25. XAML OverviewSimple general-purpose, XML based declarative programming language for constructing & initializing .NET objects

26. .NET Framework 3.0 includes

27. A compiler and run-time parser for XAML,

28. Plug-in that enables to view standalone WPF-based XAML files (sometimes called loose XAML pages) inside IE.

29. Can be used independent of WPF (e.g. WF)

30. XAML Spec defines rules that map .NET namespaces, types, properties, and events into XML namespaces, elements, and attributes.

31. Declaring an XML element in XAML (known as an object element) is equivalent to instantiating the corresponding .NET object (always via a default constructor).

32. Setting an attribute on the object element is equivalent to setting a property of the same name (called a property attribute)XAML Example<Windowx:Class="WpfApplication1.Window1"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/ presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="First XAML Example" Height="300" Width="300"> <StackPanel><Button Height="70"FontFamily="Verdana"FontSize="18">Hello World</Button></StackPanel></Window>namespace WpfApplication1{ public partial class Window1 : Window{public Window1(){InitializeComponent();} }}Window1.xaml.csWindow1.xamlButton btn =new Button();btn.Height = 70;btn.FontFamily =new FontFamily("Verdana");btn.FontSize = 18;btn.Content = "Hello World";panel.Children.Add(btn);

33. Loose XAML files<Button xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" Height="50" Width="250" FontSize="16"> Hello from loose XAML page </Button>

34. XAML Namespace<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:w="clr-namespace:WpfApplication1"XAML Namespace

35. Default Namespace: declared with xmlns attribute

36. Xmlns: http://schemas.microsoft.com/winfx/2006/xaml/presentation - maps to .NET namespace System.Windows.Controls.

37. Mapping defined in PresentationFramework.dll assembly [assembly:XmlnsDefinition (“http://schemas.microsoft.com/winfx/2006/xaml/presentation”, “System.Windows.Controls”)]

38. Root object element in a XAML file must specify at least one XML namespace: used to qualify itself & any child elements.

39. Additional XML namespaces (on the root or on children) can be declared , but each one must be given a distinct prefix to be used on any identifiers from that namespace.

40. e.g. WPF XAML files typically use a second namespace with the prefix x (denoted by using xmlns:x instead of just xmlns): xmlns:x=http://schemas.microsoft.com/winfx/2006/xaml (XAML Language namespace) – System.Windows.MarkupXML Properties and Attributes<Button>Hello World <Button.FontSize>16</Button.FontSize></Button><ButtonFontSize="16">Hello World </Button>Attribute SyntaxProperty Element Syntax<Button Width="120">Hello World</Button><Button Width="1.2in">Hello World</Button><Button Width="1.2 IN">Hello World</Button><Button Width="2.8cm">Hello World</Button><Button Width="70pt">Hello World</Button><Button Width="15e-1in">Hello World</Button><Button Width="NaN">Hello World</Button>

41. XamlReader ClassXamlReader class exposes some functionality of XAML Parser

42. Defined in namespace System.Windows.Markup

43. Load & Parse method allows to parse XAML and convert it into initialized objectApplication and Window class

44. Application classApplication object is responsible for

45. Managing the lifetime of the application

46. Tracking the visible windows

47. Dispensing resources

48. Managing the global state of the application

49. Provides Run() method to start an app

50. Most WPF apps create a subclass of Application

51. Run() method starts the dispatcher which sends the messages & events.

52. WPF requires the UI thread to be STA because many components that WPF uses (e.g. Clipboard) require STA

53. The [STAThread] marker on the entry-point function is required like Win Forms and User32First WPF Appusing System;using System.Windows;namespace ConsoleApplication1{ class Program{[STAThread]static void Main(string[]args){Window mainWin =new Window();mainWin.Title ="First WPF App";Application app =new Application();app.Run(mainWin); } }}

54. Using VS2008 WPF Template

55. Important Members of ApplicationProperty

56. Current (static) – refers to current App

57. MainWindow – points to application’s Main window

58. Windows – collection of windows of app

59. StartupUri – Uri of resource to be started if Run is called without parameter

60. ShutdownMode

61. Method

62. Run – starts the app

63. Shutdown – ends the app

64. Events

65. Startup & Exit

66. Activated & Deactivated

67. DispatcherUnhandledExceptionWindowWPF Window provides abstraction for Win32 Window

68. OS does not distinguish between windows with WPF content and normal Win32 content.

69. Similar to Form in Win Forms

70. Represented by System.Windows.Window class

71. Order of Window events1. Constructor is called.2. Window.Initialized event is raised.3. Window.Activated event is raised.134. Window.Loaded event is raised.5. Window.ContentRendered event is raised.6. User interacts with the window.7. Window.Closing event is raised.8. Window.Unloaded event is raised.9. Window.Closed event is raised.

72. Navigation WindowProvides navigation in Windows app (like navigation from one page to another in web Apps)

73. Built with three basic concepts –

74. Navigation Hosts: hosts the content like Browser

75. Navigable Content: Page

76. Journal: responsible for tracking the navigation actions<Label>This is page 1</Label><TextBlock><HyperlinkNavigateUri="Page2.xaml">Go to Page2 </Hyperlink></TextBlock>

77. Controls

78. ControlsProvides standard set of controls like Button, TextBox, CheckBox, ComboBox, RadioButton etc.

79. Provides Content property instead of familiar Win32 Text property. Content can be any object, not only string.

80. Content actually supports both string and UIElement

81. For other datatypes, it uses the string value returned by ToString().

82. Most WPF controls ship with several default appearances

83. Aero (default Windows Vista theme)

84. Luna (default Windows XP theme)

85. Royale (Media Center & Tablet PC theme)

86. Classic (Win 9x theme)

87. Provides different type of controls

88. Content Controls

89. Buttons

90. Simple Containers

91. Containers with a Header

92. Items Controls

93. Range Controls

94. Text and Ink ControlsButtonsProvides Content property - derived from ContentControl base classContent property is of type object (not text), so any content is allowed, not only text.Provides rich composition

95. Simple ContainersLabel – Can be assigned an Access Key, which can be used to set the cursor to the next TextBox.

96. ToolTip – provides rich tooltip like Office 2007

97. Frame – Can contain HTML contentContainers with HeaderGroupBox – Groups other controls. Has Header property.

98. Expander – New control in WPF. Does not exist in Win32/ WinForms.

99. Contains a button that enables you to expand and collapse the inner content.

100. By default, the Expander starts out collapsed.Items ControlComboBox

101. ListBox

102. ListView

103. TabControlCustomizing ComboBoxIsEditable=”False” (default)TextSearch.Text property setIsEditable=”True”

104. Range ControlProgressBarSlider

105. Text and Ink ControlTextBoxRichTextBoxCan Contain Rich formatted text & imagesPasswordBoxInkCanvas

106. OtherMenu, MenuItem

107. ContextMenu

108. ToolBar

109. StatusBar

110. WPF does not provide these control

111. Grid

112. CalendarSizing, Positioning and Transform

113. SizingLayout and size depends on the negotiation between Parent and Child control

114. Input

115. Height & Width property (from FrameworkElement)

116. Avoid Explicit Sizing

117. use MinHeight, MinWidth, MaxHeight & MaxWidth

118. Output

119. ActualHeight, ActualWidth (read only)

120. DesiredSize, RenderSize (UIElement)

121. Default unit of measurement in WPF is Device Independent Pixel / Logical Pixel

122. NOT in Pixel (as in WinForms) as it’s resolution dependant.

123. 1 Logical Pixel = 1/96th of an inch (regardless of the DPI setting)Unit Example<StackPanel><Button Width="120">Button 1</Button> // Device Independent Pixel<Button Width="96">Button 2</Button> // Device Independent Pixel<Button Width="1.2in">Button 3</Button> // Inches<Button Width="1.2 IN">Button 4</Button> // Inches<Button Width="5cm">Button 5</Button> // Centimeter<Button Width="5 Cm">Button 6</Button> // Centimeter<Button Width="NaN">Button 7</Button> // Not a Number<Button Width="70pt">Button 8</Button> // Point<Button Width="15e-1in">Button 9</Button> // Scientific</StackPanel>Is XAML Parser using double.Parse method behind?

124. No as it can parse NaN & Infinity but NOT in, cm, pt strings

125. It’s using DoubleConverter class from System.ComponentModelMargin (Thickness) Example<StackPanel Margin="10" Background="LightBlue"><Button Margin="10">Hello World</Button><Button Margin="10 20">Hello World</Button></StackPanel><StackPanel Margin="10" Background="LightBlue"><Button Margin="10">Hello World</Button><Button Margin="10 20 30 40">Hello World</Button></StackPanel>XAML Parser uses ThicknessConverter class from System.Windows namespace.

126. Converter ExampleSystem.ComponentModel namespace provides a base class called TypeConverter. All Converter classes ultimately derives from TypeConverter..NET FrameworkTypeConverter Supported in: 3.5, 3.0 SP1, 3.0, 2.0 SP1, 2.0, 1.1, 1.0

127. Margin, Padding and VisisbilityMargin - Controls how much extra space gets placed around the outside edges of the element

128. Padding - Controls how much extra space gets placed around the inside edges of the element

129. Visibility – NOT boolean, rather a three-state System.Windows.Visibility enumeration

130. Visible: The element gets rendered and participates in layout.

131. Collapsed: The element is invisible and does not participate in layout.

132. Hidden: The element is invisible yet still participates in layout.<StackPanel Background="LightBlue" Margin="40,30,20,10"><Button Margin="50" Padding="20">Hello World</Button></StackPanel>

133. PositionAlignmentHorizontalAlignment : Left, Center, Right, Stretch (default)VerticalAlignment: Top, Center, Bottom, Stretch (default)<StackPanel><Button HorizontalAlignment="Left">Left Button</Button><Button HorizontalAlignment="Center">Center Button</Button><Button HorizontalAlignment="Right">Right Button</Button><Button HorizontalAlignment="Stretch">Stretch Button</Button></StackPanel>

134. Position (cont’d)Content Alignment: Determines how a control’s content fills the space within the control

135. HorizontalContentAlignment : Left, Center, Right, Stretch

136. VerticalContentAlignment: Top, Center, Bottom, Stretch<StackPanel><Button HorizontalAlignment="Left">Left Button</Button><Button HorizontalAlignment="Center">Center Button</Button><Button HorizontalAlignment="Right">Right Button</Button><Button HorizontalAlignment="Stretch" MinHeight="60" HorizontalContentAlignment="Right" VerticalContentAlignment="Bottom">Stretch Button</Button></StackPanel>

137. How all properties come togetherHorizonalAlignment and VerticalAlignmentMargin and PaddingHeight and WidthTransform

138. Layout with Panels

139. PanelsAll panels derive from abstract Panelclass.

140. Panel allows adding multiple child controls (UIElement) via Children property.

141. Different type of panels -

142. StackPanel

143. WrapPanel

144. DockPanel

145. Grid and UniformGrid

146. CanvasStack PanelStacks its children (controls) sequentiallyStacks either horizontally or vertically depending on Orientation property<StackPanel Orientation="Horizontal"><Button>Button 1</Button><Button>Button 2</Button><Button>Button 3</Button></StackPanel><StackPanel><Button>Button 1</Button><Button>Button 2</Button><Button>Button 3</Button></StackPanel>

147. Wrap PanelWraps its children (controls) to additional rows or columns when there’s not enough space

148. ItemHeight, ItemWidth – uniform height & width can be set for all children (controls)<WrapPanel Orientation="Horizontal"><Button MinWidth="150">Button 1</Button><Button MinWidth="120">Button 2</Button><Button MinWidth="100">Button 3</Button><Button MinWidth="80">Button 4</Button><Button MinWidth="170">Button 5</Button><Button MinWidth="40">Button 6</Button></WrapPanel>

149. Dock PanelWraps its children (controls) to additional rows or columns when there’s not enough space<DockPanel><Button DockPanel.Dock="Top">Button 1</Button><Button DockPanel.Dock="Left">Button 2</Button><Button DockPanel.Dock="Bottom">Button 3</Button><Button DockPanel.Dock="Right">Button 4</Button><Button>Center Button</Button></DockPanel>

150. GridProvides tabular layout (rows & columns) of controls

151. Most versatile Panel & most used

152. Default Layout used by Visual Studio & Expression

153. Similar to working with Table in HTML<Grid ShowGridLines="True"><Grid.RowDefinitions><RowDefinition Height="40" /><RowDefinition Height="40" /><RowDefinition Height="40" /></Grid.RowDefinitions><Grid.ColumnDefinitions><ColumnDefinition Width="120"></ColumnDefinition><ColumnDefinition Width="*"></ColumnDefinition></Grid.ColumnDefinitions><Label Margin="7">First Name:</Label><TextBox Grid.Column="1" Margin="7"></TextBox><Label Margin="7" Grid.Row="1">Middle Name:</Label><TextBox Grid.Row="1" Grid.Column="1" Margin="7"></TextBox><Label Margin="7" Grid.Row="2">Last Name:</Label><TextBox Grid.Row="2" Grid.Column="1" Margin="7"></TextBox></Grid>

154. UniformGridSpecial type of GridProvides same height & width to all children (controls)<UniformGrid><Button>Button 1</Button><Button>Button 2</Button><Button>Button 3</Button><Button>Button 4</Button><Button>Button 5</Button><Button>Button 6</Button></UniformGrid>

155. CanvasMost basic Panel

156. Provides absolute positioning using Left, Top, Bottom & Right with explicit coordinates

157. Should not be used if possible<Canvas Background="LightBlue" ><Label Canvas.Left="10">First Name:</Label><TextBox Canvas.Left="100" MinWidth="150"></TextBox><Label Canvas.Left="20" Canvas.Top="50">Middle Name:</Label><TextBox Canvas.Left="120" Canvas.Top="50" MinWidth="150"></TextBox><Label Canvas.Left="10" Canvas.Top="140">Last Name:</Label><TextBox Canvas.Left="80" Canvas.Top="140" MinWidth="180"></TextBox></Canvas>

158. Controlling Scrolling: ScrollViewerScrollViewer: provides Scrolling capability with scroll bar<ScrollViewer><StackPanel><Button MinHeight="50">Button 1</Button><Button MinHeight="60">Button 2</Button><Button MinHeight="90">Button 3</Button><Button MinHeight="50">Button 4</Button><Button MinHeight="120">Button 5</Button><Button MinHeight="50">Button 6</Button></StackPanel></ScrollViewer>

159. ViewBoxViewBox: Scales Content to fit the window<Viewbox><StackPanel><Label>Patient Detail:</Label><StackPanel Orientation="Horizontal"><Label Foreground="Gray">Name:</Label><Label>John W Smith</Label></StackPanel><StackPanel Orientation="Horizontal"><Label Foreground="Gray">Sex:</Label><Label>Male</Label></StackPanel><StackPanel Orientation="Horizontal"><Label Foreground="Gray">Age:</Label><Label>30 yrs</Label></StackPanel><Label Foreground="Gray">Address:</Label><Label>2A Market Avenue, Minneapolis, MN, USA</Label></StackPanel></Viewbox>

160. Resources and Styles

161. ResourceDifferent from traditional .NET Resources which are binary resources (strings, images, icons etc)WPF Resources are Logical Resources.A Resource can be anything that should be reusedResources are stored in an object of type ResourceDisctionary.Each resource in resource dictionary must have unique keyThree fundamental classes (FrameworkElement, FrameworkContentElement and Application) define a property named Resource of type ResourceDisctionary.Any element derived from FrameworkElement (such as panels, controls) can have a Resource collection.

162. Resource ExampleResource Key<Window.Resources><SolidColorBrush x:Key="ButtonBackground">LightBlue</SolidColorBrush><s:Doublex:Key="ButtonFontSize">17.5</s:Double></Window.Resources><StackPanel><Button Background="{StaticResource ButtonBackground}" FontSize="{StaticResource ButtonFontSize}">Button 1</Button><Button Background="{StaticResource ButtonBackground}">Button 2</Button><Button FontSize="{StaticResource ButtonFontSize}">Button 3</Button> <Button>Button 4<Button.FontSize><StaticResource ResourceKey="ButtonFontSize" /></Button.FontSize><Button.Background><StaticResource ResourceKey="ButtonBackground" /></Button.Background> </Button></StackPanel>Attribute syntaxProperty Element syntax

163. Resource (Cont’d)Resources can be used in two ways

164. Through Markup Extension (via {})

165. Static Resource Markup Extension

166. Dynamic Resource Markup Extension

167. Through Property Element Syntax

168. Helps in consistency & reusability

169. Can be stored at different level (like individual control, panels, window or application level)

170. The markup extension class implements the ability to walk the logical tree to find the item. Element hierarchyApplication.ResourcesType themeSystem theme

171. Application Resources<Application.Resources><s:Double x:Key="bigFontSize">20</s:Double> <SolidColorBrush x:Key="buttonBg">LightBlue</SolidColorBrush></Application.Resources>App.xaml<StackPanel><ButtonFontSize="{StaticResourcebigFontSize}" Background="{StaticResourcebuttonBg}">Hello World </Button></StackPanel>Window1.xaml<Window.Resources><SolidColorBrush x:Key="buttonBg"> LightGreen</SolidColorBrush></Window.Resources><StackPanel><ButtonFontSize="{StaticResourcebigFontSize}" Background="{StaticResourcebuttonBg}">Hello World </Button></StackPanel>Window2.xaml

172. Markup Extension Example<Button Content="{Hello}"></Button>Error: WPF expects markup ExtensionOK – Displays {Hello}, Escape Character<Button Content="{}{Hello}"></Button><StackPanel><Label Foreground="Green">Machine Name:</Label><Label Content="{x:Static s:Environment.MachineName}"></Label><Label Foreground="Green">OS version:</Label><Label Content="{x:Static s:Environment.OSVersion}"></Label><Label Foreground="Green">Version:</Label><Label Content="{x:Static s:Environment.Version}"></Label><Label Foreground="Green">User Name:</Label><Label Content="{x:Static s:Environment.UserName}"></Label> <Label Foreground="Green">User Domain Name:</Label><Label Content="{x:Static s:Environment.UserDomainName}"></Label><Label Foreground="Green">System Directory:</Label><Label Content="{x:Static s:Environment.SystemDirectory}"></Label><Label Foreground="Green">Current Directory:</Label><Label Content="{x:Static s:Environment.CurrentDirectory}"></Label></StackPanel>

173. Static vs. Dynamic ResourceWPF provides two ways to access a logical resource:Statically with StaticResource, meaning the resource is applied only once (the first time it’s needed)Dynamically with DynamicResource, meaning the resource is reapplied every time it changes

174. System ResourceWPF provides out of the box System Resources:System settings encapsulated by static fields on three classes in the System.Windows namespace: SystemColors, SystemFonts, and SystemParameters<Window x:Class="WpfApplication1.Window1"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="System Resources Demo" Height="300" Width="300" Background="{x:StaticSystemColors.ActiveCaptionBrush}"><StackPanel><LabelFontFamily="{x:StaticSystemFonts.MessageFontFamily}">User:</Label><TextBox>Aniruddha</TextBox></StackPanel></Window>

175. StyleSimple mechanism for separating property values from user interface elements.

176. Conceptually similar to using CSS in HTML.

177. Consists of Property Setters.

178. Named Styles are the simplest.<Window.Resources><Style x:Key="SpecialButton"><Setter Property="Button.Background" Value="LightSlateGray"></Setter><Setter Property="Button.FontSize" Value="20.5"></Setter><Setter Property="Button.Foreground" Value="DarkBlue"></Setter><Setter Property="Button.FontFamily" Value="Verdana"></Setter></Style></Window.Resources><StackPanel><Button Style="{StaticResource SpecialButton}">Special Button</Button></StackPanel>

179. Style InheritanceStyles can be inherited: BasedOn property in Style<Window.Resources><Style x:Key="SpecialButton"><Setter Property="Button.Background" Value="LightSlateGray"></Setter><Setter Property="Button.FontSize" Value="20.5"></Setter><Setter Property="Button.Foreground" Value="DarkBlue"></Setter><Setter Property="Button.FontFamily" Value="Verdana"></Setter></Style><Style x:Key="VerySpecialButton"BasedOn="{StaticResource SpecialButton}"><Setter Property="Button.FontSize" Value="26.5"></Setter><Setter Property="Button.FontStyle" Value="Italic"></Setter><Setter Property="Button.Foreground" Value="White"></Setter></Style></Window.Resources><StackPanel><Button Style="{StaticResource SpecialButton}">Special Button</Button><Button Name="btn2" Style="{StaticResource VerySpecialButton}">Very Special Button</Button></StackPanel>

180. Restricting use of StyleUsage of Styles can be restricted through TargetType property.

181. TargetType can be set to a specific type of controls like Button, Checkbox etc so that the Style is applied to those controls only.<Window.Resources><Style x:Key="SpecialButton"TargetType="{x:Type Button}"><Setter Property="Control.Background" Value="LightSlateGray"></Setter><Setter Property="Control.FontSize" Value="18.5"></Setter><Setter Property="Control.Foreground" Value="DarkBlue"></Setter><Setter Property="Control.FontFamily" Value="Verdana"></Setter></Style></Window.Resources><StackPanel><Button Style="{StaticResourceSpecialButton}">Special Button</Button><CheckBoxStyle="{StaticResourceSpecialButton}">Special Checkbox</CheckBox></StackPanel>

182. TriggerStyle applies its values unconditionally, but a trigger performs its work based on one or more conditions

183. Three types of Triggers

184. Property triggers: Invoked when the value of a dependency property changes

185. Data triggers: Invoked when the value of a plain .NET property changes

186. Event triggers: Invoked when a routed event is raised

187. FrameworkElement, Style, DataTemplate & ControlTemplate all have a Triggers collection, but whereas Style and the template classes accept all three types, FrameworkElement only accepts event triggers.

188. This is simply because WPF development team didn’t have enough time to implement the support for version 3.0 Trigger Class Diagram

189. Property TriggerExecutes a collection of Setters when a specified property has a specified value.

190. When the property no longer has this value, the property trigger “undoes” the Setters.<Window.Resources><Style x:Key="magicButton" TargetType="Button"><Setter Property="FontSize" Value="18"></Setter><Setter Property="Foreground" Value="Green"></Setter><Setter Property="Background" Value="LightBlue"></Setter><Setter Property="FontStyle" Value="Italic"></Setter><Style.Triggers><Trigger Property="IsMouseOver" Value="True"><Setter Property="FontSize" Value="26"></Setter><Setter Property="Foreground" Value="Red"></Setter><Setter Property="Background" Value="Yellow"></Setter><Setter Property="FontWeight" Value="Bold"></Setter></Trigger></Style.Triggers></Style></Window.Resources><StackPanel><Button Style="{StaticResource magicButton}">Button 1</Button><Button Style="{StaticResource magicButton}">Button 2</Button></StackPanel>

191. Data TriggerData triggers are just like property triggers, except that they can be triggered by any .NET property rather than just dependency properties.<StackPanel Margin="10"><StackPanel.Resources><Style TargetType="{x:Type TextBox}"><Style.Triggers><DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Path=Text}" Value="disabled"><Setter Property="IsEnabled" Value="False"/></DataTrigger></Style.Triggers><Setter Property="Background" Value="{Binding RelativeSource={RelativeSource Self}, Path=Text}"/></Style></StackPanel.Resources><TextBox Margin="3"/><TextBox Margin="3"/><TextBox Margin="3"/><TextBox Margin="3"/></StackPanel>

192. MultiTriggerTo express a logical AND relationship a variation of Trigger called MultiTrigger or a variation of DataTrigger called MultiDataTrigger is used

193. MultiTrigger and MultiDataTrigger have a collection of Conditions that contain information that goes directly inside a Trigger or DataTrigger.2D GraphicsPen, Color, Brush BitmapEffect & Transform

194. Graphics OverviewProvides a new rendering and composition model –Enables to use advanced display techniques Takes advantage of the capabilities of modern graphics cardsRetained-mode GraphicsHigh Quality RenderingPainter’s AlgorithmRetained-mode Graphics – no repaintingAll Shapes (Rectangle, Ellipse) are Vector based.Vector images do not get distorted when they are enlarged.Vector graphics formats work by specifying the primitive shapes that make up the picture, and describing their positions using coordinates (or "vectors").

195. Retained-mode GraphicsGDI/GDI+ app must respond to "invalidation" events to repaint parts of the image damaged by previously overlapping images.

196. This is because GDI's graphics model is primarily a "pixel painter"—once a primitive like ellipse is rendered, GDI "forgets" the primitive.

197. The application must retain the state (geometry, formatting attributes, etc.) of all these graphic objects in order to repaint.

198. GDI programmers never have to worry about maintaining the images of user-interface controls because controls are retained-mode graphics—they are objects stored in the underlying graphics system

199. The burden of maintaining the image of the control is borne by the graphics platform itself, not by the app.

200. Retained-mode graphics is not new to GDI/Win32. In WPF ALLgraphic objects are retained. In addition to the UI controls and media primitives, 2-D Shape primitives (rectangles, ellipses, paths, etc.) and 3-D modeling primitives are retained objects.Paint (WM_PAINT) Not handled

201. High Quality RenderingHigher-quality typography: via built-in support for subpixelClearType and OpenType (including advanced features like contextual ligatures) used for all text, including text in UI controls

202. Resolution independence: Device Independent Pixel

203. Anti-aliasing, eliminating the "jagged" edges of the rendering of diagonal or curved lines

204. Higher performance in drawing and refreshing, due to WPF's better use of the underlying graphics hardware WPFWinForm/GDI/GDI+

205. Painter’s AlgorithmIn User32 and GDI, the system works on an immediate mode clipping system. When a component needs to be rendered, the system establishes a clipping bounds outside of which the component isn’t allowed to touch the pixels, and then the component is asked to paint pixels in that box.

206. This system works very well in memory constrained systems because when something changes you only have to touch the affected component – no two components ever contribute to the color of a single pixel.

207. WPF uses "painter's algorithm" painting model - Instead of clipping each component, each component is asked to render from the back to the front of the display. This allows each component to paint over the previous component's display.

208. Advantage of this model is complex, partially transparent shapes. With today’s modern graphics hardware, this model is relatively fast (which wasn’t the case when User32/ GDI were created).ColorSupports both sRGB and scRGB formatColor bgColor1 = Color.FromRgb(255, 0, 0);btn1.Background = new SolidColorBrush(bgColor1);Color bgColor2 = Color.FromArgb(50, 255, 0, 0);btn2.Background = new SolidColorBrush(bgColor2);Color bgColor3 = Color.FromScRgb(75.5f, 200.5f, 100.5f, 50.5f);btn3.Background = new SolidColorBrush(bgColor3);btn4.Background = new SolidColorBrush(Colors.Green);

209. Brushes OverviewWPF provides two types of brushes Three Color BrushSolidColorBrush , LinearGradientBrush, RadialGradientBrushThree Tile BrushVisual Brush, Drawing Brush, Image Brush

210. Brushes: Color BrushesWPF provides three Color Brush SolidColorBrushLinearGradientBrushRadialGradientBrush<Window.Background><SolidColorBrush Color="LightSteelBlue" /></Window.Background><LinearGradientBrush> <GradientStop Color="White" Offset="0" /><GradientStop Color="Black" Offset="2" /></LinearGradientBrush><RadialGradientBrush> <GradientStop Color="White" Offset="0" /> <GradientStop Color="DarkBlue" Offset="1" /></RadialGradientBrush>

211. Brushes: Tile BrushesWPF provides three Tile Brush

212. Visual Brush

213. Drawing Brush

214. Image Brush<Window.Background><VisualBrush TileMode="FlipXY" Viewport="0,0,0.5,0.5"><VisualBrush.Visual><TextBox>Aniruddha</TextBox></VisualBrush.Visual></VisualBrush></Window.Background><Window.Background><ImageBrushImageSource="C:\Users\Public\Pictures\Sample Pictures\Winter Leaves.jpg"></ImageBrush></Window.Background><Window.Background><ImageBrushTileMode="FlipXY" Viewport="0,0,0.5,0.5"ImageSource="C:\Users\Public\Pictures\Sample Pictures\Winter Leaves.jpg"></ImageBrush></Window.Background>

215. PenA Pen is a brush with a thicknessImportant Pen propertiesStartLineCap and EndLineCapLine JoinDashStyle<Line X1="20" Y1="40" X2="250" Y2="40" Stroke="Red" StrokeThickness="10" StrokeDashArray="1" StrokeDashCap="Flat" StrokeStartLineCap="Triangle" StrokeEndLineCap="Round"></Line>

216. ShapesWPF provides six Shape related classes (derived from System.Windows.Shapes.Shape)

217. Rectangle

218. Ellipse

219. Line

220. PolyLine

221. Polygon

222. Path<StackPanel><Rectangle Fill="Blue" Height="50" Width="175" Stroke="Black" StrokeThickness="5"></Rectangle><Ellipse Fill="Orange" Height="50" Width="175" Stroke="Red" StrokeThickness="3"></Ellipse><Line Stroke="Green" StrokeThickness="3" X1="20" Y1="20" X2="250" Y2="20"></Line><Polyline Points="0,0 30,30 40,50 90,50 120,30 170,20" Stroke="Blue" StrokeThickness="2"></Polyline></StackPanel>

223. Bitmap EffectWPF provides the following bitmap effectsBevelEmbossDrop ShadowBlurOuter Glow<Button Margin="10"> <Button.BitmapEffect> <DropShadowBitmapEffect/> </Button.BitmapEffect>Drop Shadow</Button>

224. TransformProvides 2D Transform classes (deriving from System.Windows.Media.Transform)

225. RotateTransform

226. ScaleTransform

227. SkewTransform

228. TranslateTransform

229. MatrixTransform

230. All FrameworkElements have two properties of type Transform:

231. LayoutTransform, which is applied before the element is laid out

232. RenderTransform (inherited from UIElement), which is applied after the layoutRotateTransformRotates an element according to values of three properties.

233. Angle: Angle of rotation, specified in degrees (default value = 0)

234. CenterX: Horizontal center of rotation (default value = 0)

235. CenterY: Vertical center of rotation (default value = 0)<StackPanel><Button>Button 1</Button><Button MinWidth="120" MinHeight="30"><Button.LayoutTransform><RotateTransform Angle="45"></RotateTransform></Button.LayoutTransform> Button 2</Button><Button>Button 3</Button></StackPanel>

236. ScaleTransformEnlarges or shrinks an element horizontally, vertically, or in both directions.

237. ScaleX: Multiplier for the element’s width (default value = 1)

238. ScaleY: Multiplier for the element’s height (default value = 1)

239. CenterX: Origin for horizontal scaling (default value = 0)

240. CenterY: Origin for vertical scaling (default value = 0)<StackPanel> <Button>Button 1</Button><Button>Button 2<Button.LayoutTransform><ScaleTransform ScaleX="2.5" ScaleY="1.5"></ScaleTransform></Button.LayoutTransform></Button><Button>Button 3</Button></StackPanel>

241. SkewTransformSlants an element according to values of four properties.

242. AngleX: Amount of horizontal skew (default value = 0)

243. AngleY: Amount of vertical skew (default value = 0)

244. CenterX: Origin for horizontal skew (default value = 0)

245. CenterY: Origin for vertical skew (default value = 0)<StackPanel> <Button>Button 1</Button><Button>Button 2<Button.LayoutTransform><SkewTransform AngleX="45" AngleY="5"></SkewTransform></Button.LayoutTransform></Button><Button>Button 3</Button></StackPanel>

246. Combining Transform: TransformGroupMultiple Transforms can be grouped using TransformGroup<StackPanel><Button>Button 1</Button><Button MinWidth="120" MinHeight="30"><Button.LayoutTransform><TransformGroup><SkewTransform AngleX="45" AngleY="5"></SkewTransform><ScaleTransform ScaleX="2" ScaleY="1.5"></ScaleTransform><RotateTransform Angle="5"></RotateTransform></TransformGroup></Button.LayoutTransform> Button 2</Button><Button>Button 3</Button></StackPanel>

247. LayoutTransform vs. RenderTransformLayoutTransform : Applied before the element is laid out

248. RenderTransform (inherited from UIElement): Applied after the layout<StackPanel><Button>Button 1</Button><Button MinWidth="120"><Button.RenderTransform><RotateTransform Angle="45" /></Button.RenderTransform> Button 2</Button><Button>Button 3</Button></StackPanel><StackPanel><Button>Button 1</Button><Button MinWidth="120"><Button.LayoutTransform><RotateTransform Angle="45" /></Button.LayoutTransform> Button 2</Button><Button>Button 3</Button></StackPanel>

249. Trees in WPFLogical Tree or Element TreeVisual Tree <DockPanel><ListBox DockPanel.Dock="Top"><ListBoxItem>Dog</ListBoxItem><ListBoxItem>Cat</ListBoxItem><ListBoxItem>Fish</ListBoxItem></ListBox><Button Height="20" Width="100" DockPanel.Dock="Top">Buy a Pet</Button></DockPanel>Logical Tree

250. Tree Helper ClassWPF exposes the functionality to traverse both the logical and visual trees

251. System.Windows.LogicalTreeHelper

252. System.Windows.Media.VisualTreeHelperTree Helper Example

253. Data Binding & Template

254. Data Binding OverviewData binding is the bridge between binding target and binding source.

255. Each Binding (represented by Binding class) has these four components:

256. a binding Target object,

257. a Target property,

258. a Binding Source,

259. a Path to the value in the binding source to use.

260. e.g if you want to bind the content of a TextBox to the Name property of an Employee object, your target object is the TextBox, the target property is the Text property, the value to use is Name, and the source object is the Employee object.

261. The target property must be a Dependency Property. Most UIElement properties are dependency properties and most dependency properties, except read-only ones, support data binding by default.Data Binding: Control to ControlProcess that establishes connection between application UI and business logic.

262. If binding has correct settings & data provides proper notifications, then, when the data changes its value, elements bound to data reflect changes automatically.<Label>Enter your name:</Label><TextBox x:Name="nameTextBox"></TextBox><Label Margin="0,20,0,0">Name Entered by you:</Label><Label x:Name="label" Content="{BindingElementName=nameTextBox, Path=Text}"></Label>Binding binding = new Binding();// Set the Source objectbinding.Source = nameTextBox;// Set the Source propertybinding.Path =new PropertyPath("Text");// Attach to Target propertylabel.SetBinding(Label.ContentProperty, binding);

263. Binding Markup ExtensionBinding is a Markup Extension similar to StaticResource & DynamicResource

264. Markup Extensions are indicated by curly braces - { and }

265. No “ or ‘ within the curly braces

266. ElementName and Path are separated by ,<Label>Enter your name:</Label><TextBox x:Name="nameTextBox"></TextBox><Label Margin="0,20,0,0">Name Entered by you:</Label><Label Content="{BindingElementName=nameTextBox,Path=Text}"></Label><Label Content="{BindingText,ElementName=nameTextBox}"></Label>Alternate Property Element Syntax<Label>Enter your name:</Label><TextBox x:Name="nameTextBox"></TextBox><Label Margin="0,20,0,0">Name Entered by you:</Label><Label x:Name="label"><Label.Content><BindingElementName="nameTextBox" Path="Text"></Binding></Label.Content></Label>

267. Binding Direction (Binding Mode)Mode Property of Binding accepts the following values -

268. OneWay: Changes to source property automatically update the target property, but changes to target property are not propagated back to source property.

269. TwoWay: Changes to either source property or target property to automatically update the other. This is default.

270. OneWayToSource: Reverse of OneWay binding. updates source property when target property changes.

271. OneTime: Source property to initialize the target property, but subsequent changes do not propagate.What triggers source updateBindings that are TwoWay or OneWayToSource listen for changes in the target property and propagate them back to the source. This is known as updating the source.

272. LostFocus: Default for TextBox.Text. Occurs when the TextBox control loses focus.

273. PropertyChanged: As you type into the TextBox.

274. Explicit: When the application calls UpdateSource.<Label>Enter your name:</Label><TextBox x:Name="nameTextBox"></TextBox><Label Margin="0,20,0,0">Name Entered by you:</Label><TextBox x:Name="label" Text="{BindingElementName=nameTextBox, Path=Text,Mode=OneWay,UpdateSourceTrigger=PropertyChanged}"></TextBox>

275. Relative SourceRefers to an element by its relationship to the target element.

276. The property is of type RelativeSource, which also happens to be a markup extension.

277. To make the source element equal the target element:{Binding RelativeSource={RelativeSource Self}}To make the source element equal the closest parent of a given type:{Binding RelativeSource={RelativeSourceFindAncestor, AncestorType={x:Type desiredType}}}<Label>Enter a name of a color:</Label><TextBox Background="{BindingRelativeSource={RelativeSource Self}, Path=Text}"> </TextBox>

278. Binding to .NET primitive datapublic class PatientManager{public string PatientName { get; set;} public PatientManager() { PatientName ="John Smith"; } }<Window x:Class="WpfApplication1.Window1"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:p="clr-namespace:WpfApplication1" Title="Data Binding - .NET primitive data" Height="300" Width="300"><Window.Resources><p:PatientManager x:Key="PatientSource"></p:PatientManager></Window.Resources><StackPanel><Label>Patient Name:</Label><TextBox Text="{Binding Source={StaticResourcePatientSource}, Path=PatientName}"></TextBox></StackPanel></Window>

279. Data Contextpublic class PatientManager{public string PatientName { get; set; } public DateTime DateOfBirth {get; set; } public string Address { get; set; } public string City { get; set; } public PatientManager() {PatientName ="John Smith";DateOfBirth =DateTime.Now;Address ="C.V.Raman Nagar";City = "Bangalore"; } }<Window x:Class="WpfApplication1.Window1"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:p="clr-namespace:WpfApplication1" Title="Data Binding - DataContext" Height="300" Width="300"><Window.Resources><p:PatientManager x:Key="PatientSource"></p:PatientManager></Window.Resources><StackPanel><StackPanel.DataContext><Binding Source="{StaticResourcePatientSource}"></Binding></StackPanel.DataContext><Label>Patient Name:</Label> <TextBox Text="{Binding Path=PatientName}" /><Label>Date of Birth:</Label> <TextBox Text="{Binding Path=DateOfBirth}" /><Label>Address:</Label> <TextBox Text="{Binding Path=Address}" /><Label>City:</Label> <TextBox Text="{Binding Path=City}" /></StackPanel></Window>

280. Binding to .NET collection data<Window.Resources><p:Patient x:Key="PatientData"></p:Patient></Window.Resources><StackPanelDataContext="{StaticResourcePatientData}"><Label>Patient Name:</Label><TextBox Text="{Binding Path=Name}" /><Label>DOB:</Label><TextBox Text="{Binding Path=Dob}" /><Label>Patient's Addresses:</Label><ListBoxItemsSource="{Binding Path=Addresses}" /></StackPanel>

281. Notification: Interface and CollectionINotifyPropertyChanged: Used to notify clients, typically binding clients, that a property value has changed. Provided in .NET 2.0

282. INotifyCollectionChanged: Notifies listeners of dynamic changes, such as when items get added and removed or the whole list is refreshed. Provided in .NET 3.0

283. ObservableCollection: WPF provided built-in implementation of a collection that exposes the INotifyCollectionChanged. Provided in .NET 3.0INotifyPropertyChanged: Example

284. INotifyCollectionChanged & ObservableCollectionTo set up dynamic bindings so that updates in collection update the UI automatically, the collection must implement the INotifyCollectionChanged interface.

285. INotifyCollectionChanged interface exposes an event that should be raised whenever the underlying collection changes.

286. ObservableCollection class provides built-in implementation of collection that exposes the INotifyCollectionChanged interface.ObservableCollection (Cont’d)

287. Template OverviewAllows to completely customize the look & feel.

288. Template allows to completely replace an element’s visual tree while keeping all of its functionality intact.

289. Default visuals for every Controlin WPF are defined in templates (and customized for each Windows theme).

290. The source code for every control is completely separated from its default visual tree representations.Template Example <Window.Resources><Style x:Key="magicButton" TargetType="Button"><Setter Property="FontSize" Value="16"></Setter><Style.Triggers><Trigger Property="IsMouseOver" Value="True"><Setter Property="FontSize" Value="26"></Setter></Trigger></Style.Triggers></Style></Window.Resources><StackPanel> <Button Style="{StaticResource magicButton}">Hello World<Button.Template><ControlTemplate><Grid><Ellipse Fill="LightBlue" Height="30" Width="150" Stroke="Red" StrokeThickness="2"></Ellipse><ContentControl HorizontalAlignment="Center" VerticalAlignment="Center">Hello</ContentControl></Grid></ControlTemplate></Button.Template></Button></StackPanel>

291. Template Binding<StackPanel><Button BorderThickness="3" Height="40" Width="150" Background="LightPink" BorderBrush="Brown" FontSize="16">Hello World<Button.Template><ControlTemplate><Grid><Ellipse Fill="{TemplateBinding ContentControl.Background}" Height="{TemplateBinding ContentControl.Height}" Width="{TemplateBinding ContentControl.Width}" Stroke="{TemplateBinding ContentControl.BorderBrush}" StrokeThickness="{TemplateBinding ContentControl.BorderThickness}"></Ellipse><ContentControl HorizontalAlignment="{TemplateBinding ContentControl.HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding ContentControl.VerticalContentAlignment}" FontSize="{TemplateBinding ContentControl.FontSize}" Content="{TemplateBinding ContentControl.Content}"></ContentControl></Grid></ControlTemplate></Button.Template></Button></StackPanel>

292. Input and Command

293. Input OverviewProvides powerful API for obtaining input from variety of devices, including the mouse, keyboard, and stylus.

294. Primary input API exposure is found on base element classes: UIElement, ContentElement, FrameworkElement, and FrameworkContentElement

295. Provide functionality for input events related to key presses, mouse buttons, mouse wheel, mouse movement, focus management, and mouse capture.

296. Additionally Keyboard class & Mouse classes provide additional API for working with keyboard & mouse input.

297. Examples of input API on the Keyboard class are the Modifiers property, which returns the ModifierKeys currently pressed

298. IsKeyDown method, which determines whether a specified key is pressed.

299. Examples of input API on the Mouse class are MiddleButton, which obtains the state of the middle mouse button, and DirectlyOver, which gets the element the mouse pointer is currently over.Loose CouplingSupports Events at different abstraction level

300. Physical Event: Supports direct Mouse events like MouseUp, MouseDown

301. Semantic Event: Supports higher level events like Click.

302. Can fire when user presses space bar (with the button in focus)

303. Can fire when user presses Enter (when the button is default)

304. Can happen when user uses mouse or stylus

305. Writing code against the Click event has two advantages:

306. Independent of specific input gesture (mouse versus keyboard),

307. NOT tied with button. Code written against the Click event depends only on a component that can be clicked. Decoupling of code to the action produced allows for more flexibility in the implementation of handlers.

308. Events suffer from a form of coupling that requires the method implementation to be of a specific signature. e.g. the delegate for Button.Click is defined as follows:public delegate void RoutedEventHandler(object sender, RoutedEventArgs e);

309. Built in CommandsWPF defines a bunch of commands so you don’t have to implement ICommand objects for Cut, Copy, and Paste and worry about where to store them.

310. WPF’s built-in commands are exposed as static properties of five different classes.

311. ApplicationCommands: Close, Copy, Cut, Delete, Find, Help, New, Open, Paste, Print, PrintPreview, Properties, Redo, Replace, Save, SaveAs, SelectAll, Stop, Undo

312. ComponentCommands: MoveDown, MoveLeft, MoveRight, MoveUp, ScrollByLine, ScrollPageDown, ScrollPageLeft, ScrollPageRight, ScrollPageUp, SelectToEnd, SelectToHome, SelectToPageDown, SelectToPageUp

313. MediaCommands:ChannelDown, ChannelUp, DecreaseVolume, FastForward, IncreaseVolume, MuteVolume, NextTrack, Pause, Play, PreviousTrack, Record, Rewind, Select, Stop

314. NavigationCommands: BrowseBack, BrowseForward, BrowseHome, BrowseStop, Favorites, FirstPage, GoToPage, LastPage, NextPage, PreviousPage, Refresh, Search, Zoom, and more

315. EditingCommands: AlignCenter, AlignJustify, AlignLeft, AlignRight, CorrectSpellingError, DecreaseFontSize, DecreaseIndentation, EnterLineBreak, EnterParagraphBreak, IgnoreSpellingError, IncreaseFontSize, IncreaseIndentation, MoveDownByLine, MoveDownByPage, MoveDownByParagraph, MoveLeftByCharacter, MoveLeftByWord, MoveRightByCharacter, MoveRightByWordBuilt In Command Example

316. Custom CommandImplement ICommand interfaceExecute: The method that executes the command specific logicCanExecute: A method returning true if the command is enabled or false if it is disabledCanExecuteChanged: An event that is raised whenever the value of CanExecute changes

317. Custom Command Example

318. Custom Command Example (Cont’d)

319. Routed EventEvents that are designed to work well with a tree of elements.

320. When a routed event is raised, it can travel up or down the visual and logical tree, getting raised on each element in a simple and consistent fashion, without the need for any custom code.

321. Helps Apps remain oblivious to details of the visual tree & is crucial to success of element composition.

322. Routing strategies: the wayinwhich event raising travels through element tree - Tunneling: The event is first raised on the root, then on each element down the tree until the source element is reached (or until a handler halts the tunneling by marking the event as handled).Bubbling: The event is first raised on the source element, then on each element up the tree until the root is reached (or until a handler halts the bubbling by marking the event as handled).Direct: The event is only raised on source element. This is same behavior as plain .NET event, except that such events can still participate in mechanisms specific to routed events.

323. RoutedEventAgrsprivate void Button_Click(object sender,RoutedEventArgse)private void button1_Click(object sender,EventArgse)Source: The element in the logical tree that originally raised the event.

324. OriginalSource: The element in the visual tree that originally raised the event.

325. Handled: A Boolean that can be set to true to mark the event as handled. This is precisely what halts any tunneling or bubbling.

326. RoutedEvent: The actual routed event object (such as Button.ClickEvent), which can be helpful for identifying the raised event when the same handler is used for multiple routed events.Dependency PropertyDependency Property (DP) & Attached Property

327. Dependency Property OverviewWPF Introduces a new Property called DP

328. Used throughout the platform to enable styling, automatic data binding, animation and more.

329. A dependency property depends on multiple providers for determining its value at any point in time.

330. Providers could be an animation continuously changing its value, a parent element whose property value trickles down to its children, and so on.

331. Biggest feature of DP is built-in ability to provide change notification.

332. DP allows property value inheritance.

333. Doesn’trefer to traditional object oriented class based inheritance, but rather the flowing of property values down the element tree.this.FontSize = 20;

334. Dependency Property Example// Declare a public object of type DependencyPropertypublic static readonlyDependencyPropertySpaceProperty;// .NET Property Wrapper (Optional)public intSpace{ get{ return (int)GetValue(SpaceProperty); } set{ SetValue(SpaceProperty, value); }}// Declare metadata such as default value of the DPFrameworkPropertyMetadatametadata =new FrameworkPropertyMetadata();metadata.DefaultValue = 1;metadata.AffectsMeasure =true;metadata.Inherits = true;metadata.PropertyChangedCallback += OnSpacePropertyChanged;// Register the Dependency PropertySpaceProperty = DependencyProperty.Register("Space",typeof(int),typeof(SpaceButton), metadata,ValidateSpaceButton);static void OnSpacePropertyChanged(DependencyObjectobj,DependencyPropertyChangedEventArgsargs) { }

335. Change Notification

336. WPF Books