1. Leading edge windows development
An introduction to
Windows Presentation Foundation
Leading edge windows development

2. Introducing WPF Available on Vista, Xp SP2, and Windows Server 2003
Hardware acceleration
Resolution independence
Declarative user interface
Object-based drawing
Dynamic control appearance (lookless controls)

3. WPF Features Web like layout model Rich drawing model
Styles and control templates
Animation
Audio and Video
Page based applications
Command model

4. WPF Applications Windows Standalone Applications
Full trust by default
Installed
XAML Browser Applications (XBAP)
Partial trust by default
Not installed
Windows: IE, Firefox
Both require .NET Framework 3.0/3.5

5. Display Technologies Same display technology for 15 years.
User32 provides familiar look and feel.
GDI/GDI+ provides drawing support for rendering shapes, text, and images.
Newer frameworks increase usability, but are fundamentally limited by base technology.

6. WPF Display Technology
WPF uses DirectX for all rendering.
WPF is not a wrapper for GDI/GDI+, it is a replacement.
DirectX is more efficient as it is able to use the video card to render textures and gradients. GDI/GDI+ can’t.
WPF still uses User32 for some things such as handling user input.

7. WPF Rendering Tiers
Hardware factors determine the tier. Factors include card Ram, pixel shaders, vertex shaders.
Tier 0
Equivalent DirectX < 7.0.
No hardware acceleration.
Tier 1
Equivalent 7.0 < DirectX < 9.0
Partial hardware acceleration.
Tier 2
Equivalent to DirectX > 9.0
All features.

8. XAML BAML <Window x:Class="WpfApplication1.Window1"
xmlns="
xmlns:x="
Title="Window1" Height="120" Width="204">
<Grid>
<TextBlock FontSize="50">WPF!</TextBlock>
</Grid>
</Window>
XAML
BAML

9. XAML Separation of design from code.
No conversion of graphical content.
Main domain is WPF user interfaces.
Understanding XAML is critical in WPF application design.

10. With XAML Wire up event handlers Define resources
Define control templates
Data bind
Animate

11. Alien Sokoban Demo

12. Class Hierarchy Overview
DispatcherObject
DependencyObject
Visual
UIElement
FrameworkElement
Shape
Control
Panel
Legend
ContentControl
Abstract
ItemsControl
Concrete

13. The Application Class Single Threaded Apartment State.
Tracks all open windows.
Allows for initialization and cleanup.
System.Windows.Application ≈ System.Windows.Forms.Application

14. Layout Layout defined using containers.
Coordinate based layout is discouraged.
Resolution-independent and size- independent interfaces.
Advantages:
Scale well on different monitors.
Adjust when content changes.
Handle transition to other languages.

15. Layout Panels
StackPanel
WrapPanel
DockPanel
Grid
UniformGrid
Canvas

16. HeaderedContentControl
Content Model
ContentControl
Tooltip
ScrollViewer
HeaderedContentControl
Label
Window
Expander
ButtonBase
UserControl
GroupBox
TabItem
Legend
<Button>
<Grid>
<Polygon Points=“...” />
</Button>
Abstract
Concrete

17. Dependency Properties
Change notification
Property value inheritance
Used in animation, data binding, and styles

18. At this point bar.Maximum = 1
Property Coercion
All WPF controls guarantee that their properties can be set in any order.
At this point bar.Maximum = 1
ScrollBar bar = new ScrollBar();
bar.Value = 100;
bar.Minimum = 1;
bar.Maximum = 200;
bar.Value = 1
bar.Value = 100

19. Registering a Dependency Property
public class MyClass {
public static readonly DependencyProperty MyNameProperty
= DependencyProperty.Register("MyName", typeof(string), typeof(MyClass),
new UIPropertyMetadata(MyClass.MyNameValueChanged));
public string MyName {
get { return (string)GetValue(MyNameProperty); }
  set { SetValue(MyNameProperty, value); } }
static void MyNameValueChanged(DependencyObject dependencyObject,
DependencyPropertyChangedEventArgs e) {
MyClass myClass = (MyClass)dependencyObject;
myClass.TextBox_Name.Text = (string)e.NewValue; }

20. Property Validation
Don’t place code in accessor, apart from SetValue and GetValue.
Use an event handler for property validation.
public class MyClass {
public static readonly DependencyProperty MyNameProperty
= DependencyProperty.Register("MyName", typeof(string), typeof(MyClass),
new UIPropertyMetadata(MyClass.MyNameValueChanged),
new ValidateValueCallback(MyClass.IsNameValid));
static bool IsNameValid(object value) {
return value == “Daniel”; }

21. Routed Events Tunnel down or bubble up the element tree.
Required for the Content Model.
Root Element
(Window)
Raised here
first
Bubbling Event
Tunneling Event
Child UIElement
Child UIElement
Event Source
Raised here
first

22. Registering a Routed Event
public abstract class ButtonBase : ContentControl, ... {
public static readonly RoutedEvent ClickEvent
= EventManager.RegisterRoutedEvent(“Click”,
RoutingStrategy.Bubble, typeof(RoutedEventHandler),
typeof(ButtonBase));
public event RoutedEventHandler Click
add { base.AddHandler(ButtonBase.ClickEvent, value); }
remove { base.RemoveHandler(ButtonBase.ClickEvent, value); } }
RoutedEventArgs args = new RoutedEventArgs(ButtonBase.ClickEvent, this);
Base.RaiseEvent(args);

23. Attaching an Event Handler
Declaratively in XAML: <Button Name=“Button_Test” Click=“Button_Click” />
Imperatively in code beside: Button_Test.Click += Button_Click;
Directly using the Routed Event: Button_Test.AddHandler(ButtonBase.ClickEvent, new RoutedEventHandler(Button_Click));
Handler: void Button_Click(object sender, RoutedEventArgs e) {...}

24. Pages and Navigation
Traditional Windows applications are window-centric, while the web is page- centric.
WPF provides for both.
FrameworkElement
Page
Control
ContentControl
Window

25. Hyperlinks <Page x:Class="WpfApplication1.Page1"
xmlns="
xmlns:x="
Title="Page1">
<Grid>
<StackPanel>
<TextBlock Width="120">Hello DEEWR</TextBlock>
<TextBlock Width="120">
<Hyperlink NavigateUri="Page2.xaml">Next</Hyperlink>
</TextBlock>
<Button Width="75" Click="button2_Click">Close</Button>
</StackPanel>
</Grid>
</Page>

26. Navigation Continued
Fragment Navigation <Hyperlink NavigateUri=“Page2.xaml#MyTextBox”> link text</Hyperlink>
Hyperlinks ok for linear and fixed series of steps.
NavigationService used for more complex scenarios.
Navigation in WPF is asynchronous.
NavigationService provides useful events for e.g. monitoring progress and cancelling navigation.

27. Page Functions Derived from Page class.
Adds ability to return a result.
No need for global variables or shared state.
<PageFunction
xmlns="
xmlns:x="
xmlns:sys="clr-namespace:System;assembly=mscorlib"
x:Class="WpfApplication1.PageFunction1"
x:TypeArguments="sys:String"
Title="PageFunction1">
<Grid></Grid>
</PageFunction>

28. Page Functions Continued
Navigate()
Page
Controller
Navigate()
PageFunction
OnReturn()
OnReturn() .
PageFunction

29. Commands Commands are higher level tasks.
Triggered by a variety of sources: Toolbar button, menu item etc.
Allows for enabling and disabling of controls.
Allows for localization.
Lacks history and undo/redo.

30. Commands continued
Business logic usually shouldn’t sit in event handlers, and may reside in separately compiled components.
Wiring up event handlers for controls can be messy.
WPF Command model
Designates events to commands
Synchronizes enabled control state
Wired up using XAML

31. Styles
Collection of property values that can be applied to a UIElement.
More powerful than CSS.
Able to modify behaviour as well as appearance.
Supports Triggers.
<Style x:Key="CenterLabels" TargetType="{x:Type Label}">
<Setter Property="Foreground" Value="White"/>
<Setter Property="FontSize" Value="25"/>
<Setter Property="VerticalAlignment" Value="Center"/>
</Style>

32. Control Templates Allows radical redesign of every control.
In the past
Customization difficult or impossible.
Had to choose between convenience (prebuilt controls) and flexibility (roll your own).

33. Data Binding
Allows binding any UIElement’s property to another UIElement’s property.
Eliminates tedious code.
Binding Directions
OneWay
TwoWay
OneTime
.NET 3.5 offers binding to LINQ expressions. Demo

34. Notable Omissions XPS Resources Accessibility Data binding validation
Animation 3D

35. Further Information

36. References Dependency Properties
MacDonald, M. 2008, Pro WPF in C# 2008, Apress
Dependency Properties Overview