Tài liệu SilverLight2Programming docx

Programming Silverlight 2+1 Trịnh Minh Cường cuong@microsoft.com Blog: http://msdnvietnam.net/blogs/cuong/default.aspx Microsoft Silverlight cross-browser (IE, FireFox, Safari) cross-platform (Moonlight on Linux) cross-device Plug-in for building and delivering the next generation of NET based media experiences and rich interactive applications http://www.go-mono.com/moonlight/ for the Web Silverlight is a NET technology SilverLight 2.0 contains subset of NET Server & Services Desktop NET Browser Devices, Mobile Silverlight extends your NET Reach SilverLight vs Adobe Flash • Flash is born in 1996, already 13 years old Current version Adobe Flash CS4, version 10 Written in C++ • SilverLight ver 1.0 (2007), 2.0 (Oct 2008) years old Written in C++, C#, NET • Flash’s strong points: • Large market share (~85%) Many samples and source codes Friendly to web and graphics designer • Motion tween, time-line story board, vector graphics • Flash’s weak points: • ActionScript 3.0 is ECMA script, not powerful programming language Easy to learn but difficult to develop advanced application: data binding, algorithm, collections manipulation • Flash format is licensed • Hard to debug  • SilverLight’s strong and weak points: • See the page “Why SilverLight” SilverLight vs JavaScript, AJAX • JavaScript is a script language to manipulate HTML elements • SilverLight 1.0 use JavaScript as programming language • SilverLight 2.0 can invoke a JavaScript function, a JavaScript can invoke function in SilverLight See demo later • SilverLight make asynchronous request~ AJAX calling • JavaScript can interact with every DOM elements in web browser • SilverLight also interact with DOM See section “Browser Integration, JavaScript interaction” • Some good JavaScript frameworks: • Jquery • Mootools • Notes: In Javascript, we can use Canvas object to draw vector graphics See more at https://developer.mozilla.org/En/Drawing_Graphics_with_Canvas Silverlight and WPF • Silverlight is a subset of WPF • Plus a few extra web features and its own codecs • Reuse strategy • Same skills • Same tools • Same XAML and UI • Silverlight code should run on WPF with minor changes • Some cool features of WPF are not yet implemented in SilverLight • 3D support • Animation along curve path • Applying template SilverLight + WPF vs Adobe AIR vs JavaFX • Since Adobe AIR and JavaFX are designed to develop Rich Internet Application on desktop, browser and mobile, WPF and SilverLight are teamed up in comparison • online surveys from Oct 2008 to Feb 2009: • 70-85% Vietnamese developers are familiar with Visual Studio, C# or VB.net • 35% Visual Studio 2005, 28% Visual Studio 2008 16% older version Visual Studio • 80% of applications are Line of Business, RDBMS centric • 90-98% VN enterprises are using XP, Vista, Windows in client PCs Why SilverLight ? • SilverLight’s strong points: • Friendly to NET programmers Visual Studio, Express Blend • XAML is cool It is XML, it can be easily generated Soon many 3rd tools will appear • Rapidly and continuously evolve with WPF Initially, its code name was WPF/e ~ WPF everywhere • Future: will be integrated into MS Office and other products • Strong 3rd parties community: ComponentOne, Infrasgistic, Telerik, • Suitable for Line of Business Applications • SilverLight ’s weak points: • Not yet support motion tween, and Animation along curve path • Not support 3D • Don’t be panic, SilverLight 3.0 to be announced in March 18th 2009 SilverLight, Flash, JavaScript usage in Hanoi, Vietnam (100 samples) Web technologies usage: ASP.net 2.0 34% ASP.net 3.5 23% SharePoint 12% PHP 13% Ruby On Rails 1% Java 5% Other 12% Web client technologies usage: Flash 33% JavaScript 22% SilverLight 2.0 13% SilverLight 1.0 4% Other 14% Programming Languages: C# 40% JavaScript 33% VB.net 19% ActionScript 9% How Flash is used in Vietnam: Use tool to generate ready made effect 38% Use template in the Internet and modify 36% Copy all 7% Self coding 19% Demo of 3rd parties • http:// www.componentone.com/SuperProducts/StudioSilverlight/Live+Exampl es/ • http://labs.infragistics.com/silverlight/lobsamples/ • http://devexpress.com/Downloads/NET/OnlineDemos.xml • http://www.netikatech.com/ • http://www.vectorlight.net/ Networking Networking • Asynchronous HTTP requests • GET/POST • Access to most headers, cookies, • Uses browser networking stack • Caching, authentication, proxy , compression Sockets • TCP only • Asynchronous API • No explicit bind and no listen/accept support • Restricted ports ( 4502-4534) • For Beta1, site of origin only, cross-domain for RTW void Connect(AddressFamily family) { SocketAsyncEventArgs connectArgs = new SocketAsyncEventArgs(); connectArgs.RemoteEndPoint = new DnsEndPoint( Application.Current.Host.Source.Host, 4502); connectArgs.Completed += new EventHandler(OnConnectCompleted); socket = new Socket(family, SocketType.Stream, ProtocolType.Tcp); if (!socket.ConnectAsync(connectArgs)) OnConnectCompleted(socket, connectArgs); } Byte-range Seeking Support • Enables seeking to non-downloaded portions of a file stored on *any* HTTP 1.1-enabled web server • Win-win for content distributors and viewers • Distributors save on bandwidth on non-viewed parts of media • Viewers get smaller latencies when seeking • When Seek is called on the MediaElement • New byte-range request is made, if needed; • Silverlight keeps track of downloaded portions of the file; • Playback continues from new position • Supported almost everywhere WebClient • Easy to use, events-based async • Download string, stream • Progress information webClient.DownloadStringCompleted += new DownloadStringCompletedEventHandler(DownloadCompleted); webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(DownloadProgressChanged); webClient.DownloadStringAsync("http://www.data.com/data.xml"); void DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e) { Stream stream = e.Result; // Use stream } Demo Prosise/VideoOverlay HttpWebRequest/Response ~ AJAX • Primary API for HTTP/HTTPS • Greater control (GET & POST, headers, etc) private void MakeAsyncRequest() { HttpWebRequest request = (HttpWebRequest) WebRequest.Create("http://foo.com/api?token=89"); IAsyncResult asyncResult = request.BeginGetResponse( new AsyncCallback(ResponseCallback), request); } private void ResponseCallback(IAsyncResult ar) { HttpWebRequest request = ar.AsyncState as HttpWebRequest; WebResponse response = request.EndGetResponse(ar); Stream responseStream = response.GetResponseStream(); // Use stream } Cross-domain support • formats: • Flash policy file • Silverlight policy file