Module 1: Creating an Application by Using Windows Presentation Foundation Overview of WPF Creating a Simple WPF Application Handling Events and Commands Navigating Between Pages

What Is WPF? It is a new foundation for building Windows-based applications by using: Media Documents Application UI.NET Framework 4.0 Windows Presentation Foundation (WPF) Windows Presentation Foundation (WPF) Windows Communication Foundation (WCF) Windows Communication Foundation (WCF) Windows Workflow Foundation (WF) Windows Workflow Foundation (WF) Windows CardSpace (WCS) Windows CardSpace (WCS)

Defining User Interfaces in WPF... Label TextBox RadioButton CheckBox Button... Label TextBox RadioButton CheckBox Button

WPF Capabilities and Features WPF provides the following capabilities and features: XAML-based user interfaces Page layout management Data binding 2-D and 3-D graphics Multimedia Animation Documents and printing Security Accessibility Localization Interoperability with Windows Forms controls

WPF Application Types Stand-Alone Applications XAML Browser Applications (XBAPs)

Defining the Application <Application xmlns:x=… xmlns=… x:Class="MyApp.App" StartupUri="Window1.xaml"> … <Application xmlns:x=… xmlns=… x:Class="MyApp.App" StartupUri="Window1.xaml"> … Visual Studio generates a XAML application file that specifies: The code-behind class for the application The startup window or page Application-wide resources

Defining Windows A stand-alone application contains windows or pages They are represented by elements in the XAML file The code-behind file contains event-handler code < Window xmlns:x=… xmlns=… x:Class="MyApp.Window1" Title="My Window"> … < Window xmlns:x=… xmlns=… x:Class="MyApp.Window1" Title="My Window"> …

Adding Controls Windows and pages contain controls The controls are represented by XAML elements and are examples of these... Click here... Click here...

The WPF Event Model WPF controls generate events such as: Clicking buttons Entering text Selecting lists Gaining focus

Implement event handler method in the code-behind file Specify an event handler in the XAML file Handling WPF Control Events Click here Click here public void Button1_Click( object sender, RoutedEventArgs e) { MessageBox.Show("Hello WPF"); } public void Button1_Click( object sender, RoutedEventArgs e) { MessageBox.Show("Hello WPF"); }

What Are Routed Events? Root element Child element #1 Child element #2 Leaf element #1 Leaf element #2 Leaf element #2 WPF can route events up or down the element tree Event bubbling: Event routed up element tree Event bubbling: Event routed up element tree Event tunneling: Event routed down element tree Event tunneling: Event routed down element tree Tunnel Bubble Item clicked

Defining Routed Events Example of event bubbling Define leaf elements inside a container element Handle leaf events at the container level Yes No Yes No private void CommonClickHandler(object sender, RoutedEventArgs e) { Button b = e.Source as Button;... } private void CommonClickHandler(object sender, RoutedEventArgs e) { Button b = e.Source as Button;... }

What Are Commands? Commands separate the semantics of an action from its logic Multiple sources can trigger the same command You can customize the command logic for different targets Key concepts in WPF commanding: Commands Command sources Command bindings Command manager Examples of predefined commands: Copy, Cut, and Paste

The WPF Navigation Model Navigate from one page to another page Navigate to a fragment in a page Navigate subcontent frames in a page

Handling Page Navigation Events Page Navigation Request Navigating NavigationProgress Navigated LoadCompleted FragmentNavigation NavigationStopped NavigationFailed

Maintaining State by Using Navigation Services Page1.xaml Page2.xaml Page1.xaml Next Back KeepAlive property FrameworkPropertyMetadata.Journal IProvideCustomContentState

Why Design Patterns? Application development is a murky business Design patterns support move from chaos to order A good pattern aids Design Implementation Testing Maintenance Extension Collaboration Separation of Concerns

MVVM Design Pattern Design Pattern for Application UIs Evolved from MVP and MVC Well suited to developing with WPF Suits WPF core features Data binding Data templates Commands Resources subsystem

MVVM Tiers Bind and Convert data UI Elements with Data Templates Object Model or Data Access Tier View View-Model Model Abstraction of View with Commands

Lab: Creating a WPF Application Exercise 1: Creating a Stand-Alone WPF Application Exercise 2: Handling Events and Commands Exercise 3: Navigating Between Pages Estimated time: 60 minutes

Lab Review Why would you want to inherit your window from the NavigationWindow class? How do you add an event handler to the Click event of a element in XAML? What is the name of the property that you use to configure a b utton to use the NextPage command? What is the name of the event to which you connect a handler if you want to manually determine if a command is allowed to be executed?