Pro Silverlight 5 in VB. Matthew Macdonald

Transcription

1 Pro Silverlight 5 in VB Matthew Macdonald

2 Pro Silverlight 5 in VB Copyright 2012 by Matthew Macdonald All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher. ISBN ISBN (ebook) Trademarked names, logos, and images may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, logo, or image we use the names, logos, and images only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. President and Publisher: Paul Manning Lead Editor: Ewan Buckingham Technical Reviewer: Fabio Claudio Ferracchiati Editorial Board: Steve Anglin, Mark Beckner, Ewan Buckingham, Gary Cornell, Morgan Ertel, Jonathan Gennick, Jonathan Hassell, Robert Hutchinson, Michelle Lowman, James Markham, Matthew Moodie, Jeff Olson, Jeffrey Pepper, Douglas Pundick, Ben Renow-Clarke, Dominic Shakeshaft, Gwenan Spearing, Matt Wade, Tom Welsh Coordinating Editor: Adam Heath Copy Editor: Kim Wimpsett Compositor: Bytheway Publishing Services Indexer: BiM Indexing & Proofreading Services Artist: SPI Global Cover Designer: Anna Ishchenko Distributed to the book trade worldwide by Springer Science+Business Media, LLC., 233 Spring Street, 6th Floor, New York, NY Phone SPRINGER, fax (201) , , or visit. For information on translations, please , or visit. Apress and friends of ED books may be purchased in bulk for academic, corporate, or promotional use. ebook versions and licenses are also available for most titles. For more information, reference our Special Bulk Sales ebook Licensing web page at. The information in this book is distributed on an as is basis, without warranty. Although every precaution has been taken in the preparation of this work, neither the author(s) nor Apress shall have any liability to any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectly by the information contained in this work. The source code for this book is available to readers at. You will need to answer questions pertaining to this book in order to successfully download the code.

3 For my family

4 Contents at a Glance Contents... vi About the Author... xxviii About the Technical Reviewer... xxix Acknowledgments... xxx Introduction... xxxi Chapter 1: Introducing Silverlight... 1 Chapter 2: XAML Chapter 3: Layout Chapter 4: Dependency Properties and Routed Events Chapter 5: Elements Chapter 6: The Application Model Chapter 7: Navigation Chapter 8: Shapes and Transforms Chapter 9: Brushes, Bitmaps, and Printing Chapter 10: Animation Basics Chapter 11: Advanced Animation Chapter 12: Sound, Video, and Deep Zoom Chapter 13: Silverlight 3D Chapter 14: Styles and Behaviors Chapter 15: Control Templates Chapter 16: Multithreading iv

5 AT A GLANCE Chapter 17: Browser Integration Chapter 18: Out-of-Browser Applications Chapter 19: ASP.NET Web Services Chapter 20: Data Binding Chapter 21: Data Controls Chapter 22: File Access Chapter 23: Networking Index v

6 Contents Contents at a Glance... iv About the Author... xxviii About the Technical Reviewer... xxix Acknowledgments... xxx Introduction... xxxi Understanding Silverlight... xxxi Silverlight System Requirements... xxxiii Silverlight vs. Flash... xxxiii Silverlight vs. HTML5... xxxiv Silverlight vs. Metro (and Windows 8)... xxxv Silverlight and WPF... xxxv The Evolution of Silverlight... xxxvi About This Book... xxxviii What You Need to Use This Book... xxxviii The Silverlight Toolkit... xxxviii Code Samples... xxxix Feedback... xxxix The Last Word... xxxix Chapter 1: Introducing Silverlight... 1 Silverlight Design Tools... 1 Visual Studio vs. Expression Blend... 2 Understanding Silverlight Websites... 2 vi

7 Creating a Stand-Alone Silverlight Project... 4 Creating a Simple Silverlight Page... 7 Adding Event-Handling Code... 9 Testing a Silverlight Application Creating an ASP.NET-Hosted Silverlight Project ASP.NET Controls That Render Silverlight Content Mixing ASP.NET Controls and Silverlight Content Silverlight Compilation and Deployment Compiling a Silverlight Application Deploying a Silverlight Application Silverlight Core Assemblies Silverlight Add-on Assemblies Assembly Caching The HTML Test Page Sizing the Silverlight Content Region Silverlight Parameters Alternate Content Creating a Friendly Install Experience The Mark of the Web The Last Word Chapter 2: XAML XAML Basics XAML Namespaces The Code-Behind Class Properties and Events in XAML Simple Properties and Type Converters Complex Properties vii

8 Attached Properties Nesting Elements Events The Full Eight Ball Example XAML Resources The Resources Collection The Hierarchy of Resources Accessing Resources in Code Organizing Resources with Resource Dictionaries Element-to-Element Binding One-Way Binding Two-Way Binding The Last Word Chapter 3: Layout The Layout Containers The Panel Background Borders Simple Layout with the StackPanel Layout Properties Alignment Margins Minimum, Maximum, and Explicit Sizes The WrapPanel and DockPanel The WrapPanel The DockPanel The Grid Fine-Tuning Rows and Columns viii

9 Nesting Layout Containers Spanning Rows and Columns The GridSplitter Coordinate-Based Layout with the Canvas Layering with ZIndex Clipping Custom Layout Containers The Two-Step Layout Process The UniformGrid Sizing Pages Scrolling with the ScrollViewer Scaling with the Viewbox Full-Screen Mode The Last Word Chapter 4: Dependency Properties and Routed Events Dependency Properties Defining and Registering a Dependency Property Dynamic Value Resolution Attached Properties The WrapBreakPanel Example Routed Events The Core Element Events Event Bubbling Handled (Suppressed) Events An Event Bubbling Example Mouse Handling Right-Clicks ix

10 Double and Triple Clicks Mouse Movements The Mouse Wheel Capturing the Mouse A Mouse Event Example Mouse Cursors Keyboard Handling Key Presses Key Modifiers Focus The Command Model Building a Command Connecting a Command The Last Word Chapter 5: Elements The Silverlight Elements Static Text Font Properties Underlining Runs Wrapping Text Trimming Text Character Spacing Images Image Sizing Image Errors Content Controls x

11 The Content Property Aligning Content Buttons The HyperlinkButton The ToggleButton and RepeatButton The CheckBox The RadioButton Tooltips and Pop-Ups Customized Tooltips The Popup Items Controls The ListBox The ComboBox The TabControl Text Controls The TextBox The PasswordBox The AutoCompleteBox The RichTextBox Creating a Text Editor Using Interactive Elements in a RichTextBox The RichTextBlock Range-Based Controls The Slider The ProgressBar Date Controls The Last Word xi

12 Chapter 6: The Application Model The Application Class Accessing the Current Application Application Properties Application Events Application Startup Initialization Parameters Application Shutdown Unhandled Exceptions Custom Splash Screens Binary Resources Placing Resources in the Application Assembly Placing Resources in the Application Package Placing Resources on the Web Class Library Assemblies Using Resources in an Assembly Downloading Assemblies on Demand Supporting Assembly Caching The Last Word Chapter 7: Navigation Loading User Controls Embedding User Controls in a Page Hiding Elements Managing the Root Visual Retaining Page State Browser History Child Windows xii

13 Designing a ChildWindow Showing a ChildWindow The Frame and Page Frames URI Mapping Forward and Backward Navigation Hyperlinks Pages Navigation Templates Custom Content Loaders Authentication and Navigation Creating a Custom Content Loader Using the Custom Content Loader The Last Word Chapter 8: Shapes and Transforms Basic Shapes The Shape Classes Rectangle and Ellipse Sizing and Placing Shapes Sizing Shapes Proportionately with a Viewbox Line Polyline Polygon Line Caps and Line Joins Dashes Paths and Geometries Line, Rectangle, and Ellipse Geometries xiii

14 Combining Shapes with GeometryGroup Curves and Lines with PathGeometry The Geometry Mini-Language Clipping with Geometry Transforms Transforming Shapes Transforms and Layout Containers A Reflection Effect Perspective Transforms The PlaneProjection Class Applying a Projection Exporting Clip Art Expression Design Conversion Save or Print to XPS The Last Word Chapter 9: Brushes, Bitmaps, and Printing Brushes The LinearGradientBrush Class The RadialGradientBrush Class The ImageBrush Transparency Opacity Masks Making the Silverlight Control Transparent Pixel Shaders BlurEffect DropShadowEffect xiv

15 ShaderEffect The WriteableBitmap Class Generating a Bitmap Capturing Content from Other Elements Printing Printing a Single Element Printing Over Multiple Pages Bitmap and Vector Printing Creating a Print Preview The Last Word Chapter 10: Animation Basics Understanding Silverlight Animation The Rules of Animation Creating Simple Animations The Animation Class The Storyboard Class Starting an Animation with an Event Trigger Starting an Animation with Code Configuring Animation Properties Animation Lifetime Simultaneous Animations Controlling Playback Animation Easing Using an Easing Function Easing In and Easing Out Easing Function Classes Animation Performance xv

16 Desired Frame Rate Hardware Acceleration Independent Animations The Last Word Chapter 11: Advanced Animation Animation Types Revisited Animating Transforms Animation Perspective Projections Animating Brushes Animating Pixel Shaders Key-Frame Animation Animations in Code The Main Page The Bomb User Control Dropping the Bombs Intercepting a Bomb Counting Bombs and Cleaning Up Encapsulating Animations Page Transitions The Base Class The Wipe Transition Frame-Based Animation The Last Word Chapter 12: Sound, Video, and Deep Zoom Supported File Types The MediaElement Controlling Playback xvi

17 Handling Errors Playing Multiple Sounds Changing Volume, Balance, and Position Playing Video Trick Play Media Commands Client-Side Playlists Server-Side Playlists Progressive Downloading and Streaming Adaptive Streaming Advanced Video Playback Video Encoding Encoding in Expression Encoder Markers VideoBrush Video Effects Low-Latency Sound Play a Sound with SoundEffect Changing Playback Settings Overlapping Sounds with SoundEffectInstance Looping Audio Webcam and Microphone Input Accessing a Capture Device Basic Webcam Support Recording Audio Snippets Deep Zoom Creating a Deep Zoom Image Set xvii

18 Using a Deep Zoom Image Set in Silverlight The Last Word Chapter 13: Silverlight 3D Understanding 3D in Silverlight Adding Assembly References Enabling 3D in a Silverlight Project Basic 3D Drawing The 3D Coordinate System Filling the Vertex Buffer Positioning the Camera Configuring the BasicEffect Drawing the Scene Backface Culling Scaling Your Drawing Complex Objects and Textures Drawing a Cube Adding Textures Lighting an Object Creating Multiple Objects Using Models Movement and Animation Moving a Shape Rotating a Shape Shape Animations Rotating and Moving the Camera The Last Word xviii

19 Chapter 14: Styles and Behaviors Styles Defining a Style Applying a Style Dynamic Styles Style Inheritance Organizing Styles Automatically Applying Styles by Type Style Binding Expressions Behaviors Getting Support for Behaviors Triggers and Actions Creating a Behavior Finding More Behaviors The FluidMoveBehavior The Last Word Chapter 15: Control Templates Template Basics Creating a Template Reusing Control Templates The ContentPresenter Template Bindings Setting Templates Through Styles Reusing Colors The Parts and States Model Understanding States with the Button Control Showing a Focus Cue xix

20 Transitions Understanding Parts with the Slider Control Layout Transitions Creating Templates for Custom Controls Planning the FlipPanel Control Creating the Solution Starting the FlipPanel Class Adding the Default Style with Generic.xaml Choosing Parts and States Starting the Default Control Template The FlipButton Control Defining the State Animations Wiring Up the Elements in the Template Using the FlipPanel Using a Different Control Template The Last Word Chapter 16: Multithreading Understanding Multithreading The Goals of Multithreading The DispatcherTimer The Thread Class Marshaling Code to the User Interface Thread Creating a Thread Wrapper Creating the Worker Class Using the Thread Wrapper Cancellation Support The BackgroundWorker xx

21 Creating the BackgroundWorker Running the BackgroundWorker Tracking Progress Supporting Cancellation The Last Word Chapter 17: Browser Integration Interacting with HTML Elements Getting Browser Information The HTML Window Popup Windows Inspecting the HTML Document Manipulating an HTML Element Handling JavaScript Events Code Interaction Calling Browser Script from Silverlight Calling Silverlight Methods from the Browser Instantiating Silverlight Objects in the Browser Combining Silverlight and HTML Content Sizing the Silverlight Control to Fit Its Content Placing the Silverlight Control Next to an HTML Element Securing HTML Interoperability The Last Word Chapter 18: Out-of-Browser Applications Understanding Out-of-Browser Support Creating an Out-of-Browser Application Installing an Out-of-Browser Application Customizing Icons xxi

22 Tracking Application State Removing and Updating an Application Silent Installation Out-of-Browser Application Features The WebBrowser Control Notification Windows Controlling the Main Window Elevated Trust Installing an Elevated-Trust Application The Abilities of an Elevated-Trust Application Window Customization Child Windows COM P/Invoke Elevated-Trust Applications in the Browser The Last Word Chapter 19: ASP.NET Web Services Building Web Services for Silverlight Creating a Web Service Adding a Service Reference Calling the Web Service Configuring the Web Service URL Using a Busy Indicator Web Service Data Types Custom Data Classes Web Service Type Sharing More Advanced Web Services xxii

23 Cross-Domain Web Service Calls Monitoring the Network Connection Using ASP.NET Platform Services WCF RIA Services Duplex Services Configuring the Service The Interfaces The Service The Client The Last Word Chapter 20: Data Binding Binding to Data Objects Building a Data Object Displaying a Data Object with DataContext Storing a Data Object as a Resource Null Values and Failed Bindings Editing with Two-Way Bindings Change Notification Debugging a Data Binding Expression Building a Data Service Calling a Data Service Binding to a Collection of Objects Displaying and Editing Collection Items Inserting and Removing Collection Items Binding to a LINQ Expression Master-Details Display Validation xxiii

24 Error Notifications The BindingValidationFailed Event The Validation Class Creating Data Objects with Built-in Validation Data Formatting and Conversion String Formatting Value Converters Formatting Strings with a Value Converter Creating Objects with a Value Converter Applying Conditional Formatting Data Templates Separating and Reusing Templates Implicit Data Templates More Advanced Templates Changing Item Layout The Last Word Chapter 21: Data Controls Better Data Forms The Goal: Data Class Markup The Label The DescriptionViewer The ValidationSummary Data Annotations Raising Annotation Errors The Annotation Attributes The DataGrid Creating a Simple Grid xxiv

25 How Columns Are Resized and Rearranged Defining Columns Formatting and Styling Columns Controlling Column Width Formatting Rows Row Details Freezing Columns Selection Sorting DataGrid Editing Editing with Templates Validation and Editing Events The PagedCollectionView Sorting Filtering Grouping Paging The TreeView Filling a TreeView A Data-Bound TreeView The PivotViewer Defining the PivotViewer Navigating the PivotViewer The Last Word Chapter 22: File Access Isolated Storage The Scope of Isolated Storage xxv

26 What to Put in Isolated Storage Using Isolated Storage Opening an Isolated Store File Management Writing and Reading Data Requesting More Space Storing Objects with XmlSerializer Storing Application Settings Accessing Files Outside of Isolated Storage Reading Files with OpenFileDialog Writing Files with SaveFileDialog Transmitting Files with a Web Service Dragging and Dropping Files File Access in Elevated Trust Applications Accessing User Files Managing Directories and Files Creating a Directory Tree The Last Word Chapter 23: Networking Interacting with the Web Cross-Domain Access HTML Scraping REST and Other Simple Web Services Using Network Credentials Processing Different Types of Data XML Services That Return XML Data xxvi

27 Services That Require XML Data Services That Return SOAP Data Services That Return JSON Data RSS Sockets Understanding Sockets and TCP Understanding Policy Files The Policy Server The Messaging Server The Messenger Client Local Connections Sending a Message Receiving a Message The Last Word Index xxvii

28 About the Author Matthew MacDonald is an author, educator, and former Microsoft MVP for Silverlight. He s the author of more than a dozen books about.net programming, including Pro WPF in C# 2010, Pro ASP.NET 4 in C# 2010, and Beginning ASP.NET in C# He s also the author of Your Brain: The Missing Manual (O Reilly), a popular look at getting the most from your squishy gray matter. Matthew lives in Toronto with his wife and two daughters. xxviii

29 About the Technical Reviewer A prolific writer on cutting-edge technologies, Fabio Claudio Ferracchiati has contributed to more than a dozen books on.net, C#, Visual Basic, and ASP.NET. He is a.net Microsoft Certified Solution Developer and lives in Rome, Italy. xxix

30 Acknowledgments No author can complete a book without a small army of helpful individuals. I m deeply indebted to the whole Apress team, including Adam Heath and Ewan Buckingham, who shepherded the book through its various stages; Fabio Ferracchiati and Damien Foggon, who hunted down stray errors in this and previous editions of the book; and Kim Wimpsett, who copy edited the text. Finally, I d never write any book without the support of my wife and these special individuals: Nora, Razia, Paul, and Hamid. Thanks everyone! xxx

31 Introduction Silverlight is a framework for building rich, browser-hosted applications that run on a variety of operating systems. Silverlight works its magic through a browser plug-in. When you surf to a web page that includes Silverlight content, this browser plug-in runs, executes the code, and renders that content in a specifically designated region of the page. The important part is that the Silverlight plug-in provides a richer environment than the traditional blend of HTML and JavaScript that powers ordinary web pages. Used carefully and artfully, you can create Silverlight pages that play video, have hardwareaccelerated 3D graphics, and use vector animations. Understanding Silverlight Silverlight uses a familiar technique to go beyond the capabilities of standard web pages: a lightweight browser plug-in. The advantage of the plug-in model is that the user needs to install just a single component to see content created by a range of different people and companies. Installing the plug-in requires a small download and forces the user to confirm the operation in at least one security dialog box. It takes a short but definite amount of time, and it s an obvious inconvenience. However, once the plug-in is installed, the browser can process any content that uses the plug-in seamlessly, with no further prompting. Figure 1 shows two views of a page with Silverlight content. At the top is the page you ll see if you don t have the Silverlight plug-in installed. At this point, you can click the Get Microsoft Silverlight picture to be taken to Microsoft s website, where you ll be prompted to install the plug-in and then sent back to the original page. On the bottom is the page you ll see once the Silverlight plug-in is installed. xxxi

32 INTRODUCTION Figure 1. Installing the Silverlight plug-in xxxii

33 INTRODUCTION Note At the time of this writing, Silverlight 4 is installed on an estimated 75 percent of Internet-connected computers (including desktop and mobile devices). The share is higher if you consider only Windows operating systems or Internet Explorer browsers. Although this is impressive, it pales in comparison to Flash, which has version 10 or better installed on a staggering 96 percent of all web devices. (To get up-to-date statistics, refer to.) Silverlight System Requirements With any web-centric technology, it s keenly important to have compatibility with the widest possible range of computers and devices. And although Silverlight isn t completely cross-platform, its compatibility stacks up well on the majority of desktop computers. Currently, Silverlight supports the following: Windows computers: Silverlight works on PCs with Windows 7, Windows Vista, and Windows XP. The minimum browser versions that Silverlight supports are Internet Explorer 6, Firefox 1.5, and Google Chrome 4.0. Silverlight will also work in Windows 2000, but only with Internet Explorer 6. Other browsers, such as Opera and Safari (for Windows), aren t currently supported. Mac computers: Silverlight works on Mac computers with OS X or newer, provided they have Intel hardware (as opposed to the older PowerPC hardware). The minimum browser versions that Silverlight supports are Firefox 2 and Safari 3. Silverlight does not run on mobile Apple devices, which includes the iphone, ipod Touch, and ipad. Linux computers: Although Silverlight 5 doesn t work on Linux, the Mono team has created an open source Linux implementation called Moonlight. The last officially released version supports Silverlight 2 applications, although there is also a released preview version that supports Silverlight 4. Progress is slow, and it s uncertain when (and if) there will be a Moonlight that supports Silverlight 5. Windows Phone: Silverlight is also one of two development frameworks for Windows Phone 7 (the other being the game-focused Microsoft XNA). However, developing for Windows Phone raises some unique considerations, and there are some subtle feature differences. To learn more about WP7 development, you can refer to a dedicated book, like Pro Windows Phone 7 Development. Installing Silverlight requires a small-sized setup (around 6MB) that s easy to download. That allows it to provide an all-important frictionless setup experience, much like Flash. Silverlight vs. Flash The most successful browser plug-in is Adobe Flash, which is installed on more than 90 percent of the world s web browsers. Flash has a long history that spans more than ten years, beginning as a straightforward tool for adding animated graphics and gradually evolving into a platform for developing interactive content. xxxiii

34 INTRODUCTION It s perfectly reasonable for.net developers to create websites that use Flash content. However, doing so requires a separate design tool and a completely different programming language (ActionScript) and programming environment (Flex). Furthermore, there s no straightforward way to integrate Flash content with server-side.net code. For example, creating Flash applications that call.net components is awkward at best. Using server-side.net code to render Flash content (for example, a custom ASP.NET control that spits out a Flash content region) is far more difficult. That s where Silverlight fits into the picture. Silverlight aims to combine the raw power and crossplatform support of Flash with a first-class programming platform that incorporates the fundamental concepts of.net. As a result, developers can write client-side code for Silverlight in the same language they use for server-side code (such as C# and VB), and they use many of the same abstractions (including streams, controls, collections, generics, and LINQ). In short, for.net developers Silverlight is both a more convenient and a more powerful choice for rich Internet applications. Silverlight vs. HTML5 When Silverlight was first created, it was intended as an all-purpose way to build rich web pages and a competitor to Adobe Flash. However, in the several Silverlight versions since, the world has changed. Although Adobe Flash is still supported by virtually every desktop computer, it s been locked out of popular Apple products like the iphone and ipad. As a result, the mobile world is gravitating to different solutions, including native applications (which are limited to just one operating system) or HTML5. A broad consensus exists that HTML5 is the future of the Web, someday. However, the features that HTML5 promises (when it s fully adopted) still fall far short of the features that are available today in Flash and Silverlight. For some applications, these shortcomings don t matter. And, without doubt, the capabilities of HTML5 will strengthen in the future. But in the meantime, developers are forced to choose between features now, if they need them (in which case they re likely to pick Silverlight) and the broadest possible compatibility for all computers and mobile devices (in which case they ll probably prefer HTML5). This dilemma is also described as rich versus reach. Silverlight is the rich side of this equation it gives applications the most powerful and mature feature set. HTML5 is the reach, because it embraces every modern desktop browser. Because of this upheaval, many Silverlight developers are uncertain about exactly where their favorite technology fits into the world of web development. And while the future is far from certain, here are a few points to keep in mind: HTML5 isn t quite here yet: HTML5 support lags in in Internet Explorer. Many HTML5 features are promised for the not-yet-released IE 10, some features are available in the relatively recent IE 9, but IE 8 has no HTML5 smarts. This is a problem, because IE 8 is the best version of IE that can run on the still-widespread Windows XP platform. For all these reasons, HTML5 remains currently has less support than Silverlight, and this situation may take years to change. Silverlight has features that have no HTML5 equivalent: Even in the browsers that offer the best possible HTML5 support fall behind Silverlight in a few key areas. They can t offer the same video streaming features, the same hardware-accelerated graphics, or the same deep networking support. Nor do they support file access, out-of-browser applications, or the ability to call Windows system components. And it s hard to imagine HTML5 ever duplicating some of Silverlight s more specialized features, like the PivotViewer control that fuses together data filtering, fluid animations, and image scaling in one easy-to-use package (Chapter 21). Silverlight has a higher-level programming API: Features such as data binding, styles, and templates may not be essential for building an application, but they are important for building one quickly and efficiently. Many things that are possible in HTML5 are a manageability nightmare in all but the xxxiv

35 INTRODUCTION most disciplined hands. The JavaScript language is notoriously lax in letting syntax errors slide, all animation routines must be written by hand, and multithreading support is clumsy at best. Silverlight has top-tier development tools: Thanks to Visual Studio, you can build a Silverlight application just as easily as you build a desktop program. Add Expression Blend to the picture, and you also have a way to define and customize rich graphical effects, like animations. Silverlight offers ASP.NET integration: In particular, Silverlight makes it easy to query server-side databases through a web service. This state of affairs has led some developers to speculate that even when HTML5 does finally conquer the world, Silverlight will remain as a first choice for line-ofbusiness development inside closed company networks. No one s quite sure of Silverlight s future. It may continue on as a first-choice platform for.net developers creating business applications, or it may gradually transition into a more specialized tool for cutting-edge games and video players. One thing is settled, however: Silverlight will never replace HTML as the main language for creating traditional, public websites nor does it intend to. Silverlight vs. Metro (and Windows 8) When Microsoft announced Windows 8, complete with yet another programming model for rich client applications, Silverlight developers paused. Some wondered if that technology named Metro was an eventual Silverlight replacement. The answer is clearly no. Metro is designed to facilitate an entirely different sort of application: a lightweight, touch-centric, data-consuming application that can run on the future generation of Windows 8 powered tablets. In a very real sense, Metro is a competitor to native apps on the ipad, as well as a potential successor to Microsoft s other rich desktop programming framework, WPF (see the next section). However, Metro applications have no ability to run on non-microsoft platforms or any version of Windows other than Windows 8. For that reason, they are of little interest to Silverlight developers. In the future, the range of Silverlight applications may narrow, squeezed between cross-platform HTML5 applications that are gradually growing more sophisticated and native Metro or ipad applications for mobile devices. However, today Silverlight still occupies the very important space between these other technologies. Silverlight and WPF One of the most interesting aspects of Silverlight is the fact that it borrows the model WPF uses for rich, client-side user interfaces. WPF is a toolkit for building rich Windows applications. WPF is notable because it not only simplifies development with a powerful set of high-level features, it also increases performance by rendering everything through the DirectX pipeline. To learn about WPF, you can refer to Pro WPF in VB 2010 (Apress). Silverlight obviously can t duplicate the features of WPF, because many of them rely deeply on the capabilities of the operating system, including Windows-specific display drivers and DirectX technology. However, rather than invent an entirely new set of controls and classes for client-side development, Silverlight uses a subset of the WPF model. If you ve had any experience with WPF, you ll be surprised to see how closely Silverlight resembles its big brother. Here are a few common details: xxxv

36 INTRODUCTION To define a Silverlight user interface (the collection of elements that makes up a Silverlight content region), you use XAML markup, just as you do with WPF. You can even map data to your display using the same data-binding syntax. Silverlight borrows many of the same basic controls from WPF, along with the same styling system (for standardizing and reusing formatting) and a similar templating mechanism (for changing the appearance of standard controls). To draw 2D graphics in Silverlight, you use shapes, paths, transforms, geometries, and brushes, all of which closely match their WPF equivalents. Silverlight provides a declarative animation model that s based on storyboards and works in the same way as WPF s animation system. To show video or play audio files, you use the MediaElement class, as you do in WPF. Note WPF is not completely cut off from the easy deployment world of the Web. WPF allows developers to create browser-hosted applications called XBAPs (XAML Browser Applications). These applications are downloaded seamlessly, cached locally, and run directly inside the browser window, all without security prompts. However, although XBAPs run in Internet Explorer and Firefox, they are still a Windows-only technology, unlike Silverlight. The Evolution of Silverlight Silverlight 1 was a relatively modest technology. It included 2D drawing features and media playback support. However, it didn t include the CLR engine or support for.net languages, so developers were forced to code in JavaScript. Silverlight 2 was a dramatic change. It added the CLR, a subset of.net Framework classes, and a user interface model based on WPF. As a result, Silverlight 2 was one of the most hotly anticipated releases in Microsoft s history. The versions of Silverlight since haven t been as ambitious. Silverlight 5 keeps the same development model that was established in Silverlight 2 but adds a carefully selected group of features and performance enhancements. They highlights include the following: Performance improvements: Silverlight 5 starts faster, supports 64-bit browsers, and provides cleaner, crisper text rendering at small sizes. Vector printing: Silverlight improves its printing model to use vector printing, when possible (namely, if the print driver supports PostScript). The result is faster printing with less memory overhead (Chapter 9). Hardware-accelerated 3D graphics: Silverlight ports over a portion of the Microsoft XNA framework used for building Xbox games. With it comes a powerful but very low-level interface for rendering 3D scenes. Best of all, the video card does all the work, ensuring blistering performance (Chapter 13). Low-latency sound: Another benefit from Microsoft XNA is Silverlight s new support for low-latency sound playback. This is particularly useful for games that can t afford the slightest bit of lag (Chapter 12). xxxvi

37 INTRODUCTION Trick play: A new frill lets you play videos faster or slower, without changing the pitch of the audio. This allows users to get their content (for example, watch a video of a lecture) at their preferred speed (Chapter 12). Double-click and triple-click: A minor enhancement solves a long-standing Silverlight annoyance. You can now easily distinguish between a single click and the two clicks in quick succession that represent a double-click. Silverlight even lets you look for triple-clicks (Chapter 4). Remote media control support: It s now possible to react to playback commands sent from a remote control or enhanced keyboard with media control buttons, provided your application is running in full-screen mode (Chapter 12). Pivot viewer: This all-in-one control gives you a unique new way to present huge collections of data. It combines scalable pictures, data filtering, and fluid animations to create a seamless viewing experience. And best of all, you need to add hardly a line of your own code (Chapter 21). XAML debugging: You can now troubleshoot data binding errors by placing a breakpoint in your data binding expression (Chapter 20). Child windows: Out-of-browser applications can now show secondary windows, just like real Windows applications. They don t even need elevated trust (Chapter 18). Full file access and P/Invoke: Applications that run with elevated trust can now easily access any file on the hard drive that the user can access (except for those that require administrator privileges). They can also use P/Invoke on Windows computer to call legacy C functions or the Windows API (Chapter 18). Elevated-trust in-browser applications: This new sort of application combines the benefits of elevated trust with the streamlined no-install deployment of an ordinary Silverlight application. But there s a significant catch this option is feasible only in a controlled environment (say, inside a company network), where you can configure the certificates on all your clients (Chapter 18). Note This book contains everything you need to master Silverlight 5. You don t need any experience with previous versions of Silverlight. However, if you have developed with Silverlight 4, you ll appreciate the What s New tip boxes that follow the introduction in each chapter. They point out features that are new to Silverlight 5, so you can home in on its changes and enhancements. BACKWARD COMPATIBILITY IN SILVERLIGHT 5 At this point, you might be wondering if older Silverlight applications can run on a computer that has only the latest version of the Silverlight plug-in (version 5) installed. It s a reasonable question, because Silverlight 5 introduces some subtle changes and bug fixes that can influence the way applications work and even change its behavior. xxxvii

38 INTRODUCTION However, Silverlight 5 prevents these differences from causing problems by using its quirks mode feature. When the Silverlight 5 plug-in loads an application that was compiled for an earlier version of Silverlight, it automatically switches into a quirks mode that attempts to emulate the behavior of the appropriate Silverlight runtime environment. For more detailed information about breaking changes between Silverlight 4 and Silverlight 3, you can refer to. About This Book This book is an in-depth exploration of Silverlight for professional developers. You don t need any experience with WPF or previous versions of Silverlight, but you do need to know the.net platform, the VB language, and the Visual Studio development environment. What You Need to Use This Book To run Silverlight applications, you simply need the Silverlight browser plug-in, which is available at. To create Silverlight applications (and open the sample projects included with this book), you need Visual Studio 2010 and the Silverlight 5 Tools for Visual Studio Although they re in beta at the time of this writing, you can download the latest versions by searching for Silverlight 5 tools at the Microsoft Download Center,. Alternatively, you can use Expression Blend a graphically oriented design tool to create, build, and test Silverlight applications. Overall, Expression Blend is intended for graphic designers who spend their time creating serious eye candy, while Visual Studio is ideal for code-heavy application programmers. This book assumes you re using Visual Studio. If you d like to learn more about Expression Blend, you can consult one of many dedicated books on the subject. The Silverlight Toolkit To keep in touch with Silverlight s latest developments, you should also download Microsoft s impressive Silverlight Toolkit, which provides a set of controls and components that extend the features of Silverlight. You can use them in your Silverlight applications simply by adding an assembly reference. The Silverlight Toolkit isn t just a package of useful tools. It s also a development process that gradually brings new controls into the Silverlight platform. Many new controls appear first in the Silverlight Toolkit, are gradually refined, and then migrate to the core platform. Examples of controls that have made the jump from the Silverlight Toolkit to the core Silverlight plug-in include the AutoCompleteBox, TreeView, and Viewbox. To understand how this process works, you need to understand a bit more about the Silverlight Toolkit s quality bands groups of controls at a particular evolutionary stage. The Silverlight Toolkit divides its features into four quality bands: Mature: The mature band has controls that are unlikely to change. Usually, these are controls that are already included with the core Silverlight plug-in. However, the Silverlight Toolkit gives you access to their complete source code, which opens up customization possibilities. xxxviii

39 INTRODUCTION Stable: The stable band includes controls that are ready for inclusion in just about any application however, there may be further tweaks and fixes in the future that subtly change behavior. This book describes many of the stable controls, including the DockPanel, WrapPanel, and Expander. Preview: The preview band includes controls that are reliable enough for most applications but are likely to change in response to developer comments, so you expect to change your code before using newer versions. Experimental: The experimental band includes new controls that are intended to solicit developer feedback. Feel free to play with these, but include them in an application at your own risk. To learn more about the different quality bands, try the controls with live demos, or download the Silverlight Toolkit for yourself, go to. At the time of this writing, the current version of the Silverlight Toolkit is called the Silverlight 4 Toolkit, but it works equally well with Silverlight 5. Code Samples It s a good idea to check the Apress website at to download the up-to-date code samples. You ll need to do this to test most of the more sophisticated code examples described in this book because the less significant details are usually left out. This book focuses on the most important sections so that you don t need to wade through needless extra pages to understand a concept. Feedback This book has the ambitious goal of being the best tutorial and reference for programming Silverlight. Toward that end, your comments and suggestions are extremely helpful. You can send complaints, adulation, and everything in between directly to. I can t solve your Silverlight problems or critique your code, but I will benefit from information about what this book did right and wrong (or what it may have done in an utterly confusing way). The Last Word As you ve seen, Silverlight 5 is the latest iteration of Microsoft s.net-based, plug-in-powered web programming environment. Silverlight began its life as a Flash competitor. It continues today as a platform for building rich applications that need high-performing graphics, animations, and video. For some, it s a lightweight version of.net that you can deploy use without installation headaches. For others, it s a way to get hardware-accelerated 3D games running right inside a browser. For still others, it s a most mature, productive, cross-platform framework for business applications provided you don t need to support mobile devices. And no matter where the Web goes over the next few years, Silverlight will continue to power some of the most impressive rich Internet applications. xxxix