Introduction to ASP.NET What is.NET What is ASP.NET and how is different from ASP –ASP: server side technology for creating dynamic web pages using scripting languages eg vb script. –ASP.NET: server side technology for creating dynamic web pages using Fully Fledged programming languages supported by.NET –VB.NET: our chosen language for writing ASP.NET pages

What is.NET? A Microsoft strategy and new technology for delivering software services to the desktop and to the web Components include: – MS Intermediate Language; all code is complied into a more abstract, trimmed version before execution. All.NET languages are compiled to MSIL – the common language of.NET – The CLR- common language runtime; responsible for executing MSIL code; interfaces to Windows and IIS – A rich set of libraries (Framework Class Libraries) available to all.NET languages – The.NET languages such as C#, VB.NET etc that conform to CLR – ASP.NET is how the Framework is exposed to the web, using IIS to manage simple pages of code so that they can be complied into full.NET programs. These generate HTML for the browser. Built on open protocols (XML, SOAP) Future for development of MS & non-MS based systems. Also heading towards the “Internet Operating System”

Common Language Runtime Type System Compilers use the runtime type system to produce type compatible components Components Compilers Common Type System C#VBC++ Runtime Environment

Robust And Secure Native code compilation MSIL No interpreter Install-time or run-time IL to native compilation Code correctness and type-safety IL can be verified to guarantee type-safety No unsafe casts, no uninitialized variables, no out-of-bounds array indexing Evidence-based security Policy grants permissions based on evidence (signatures, origin)

.NET Execution Model VBVC...Script IL Native Code Common Language Runtime Standard JIT Compiler

Common Language Runtime Lightweight Just-in-time compiler: –MSIL to Native machine language –Can be ported to numerous platforms –Free/Net BSD UNIX port has been announced –“MONO” Open source movement

Framework Overview Base Class Library Common Language Specification Common Language Runtime Data and XML VBC++C# Visual Studio.NET Web Forms (ASP.NET) JScript… Win Forms

.NET Framework Architecture Common Language Runtime MetadataType SystemExecution System Base Framework IONetSecurityServiceProcess ADO.NETXMLSQLThreading System.Web Web ServicesWeb Forms ASP.NET Application Services System.WinForms ControlsDrawing Windows Application Services

ASP.NET ASP.NET provides a means of exposing the.NET Framework and its functionality to the WWW Contains a number of pre-built types that take input from.NET types and represents them in a form for the web (such as HTML) Class browser: lus/samples/classbrowser/vb/classbrowser.aspx lus/samples/classbrowser/vb/classbrowser.aspx

Web Services Web Services also provide a means to expose.NET functionality on the web but Web Services expose functionality via XML and SOAP (cf: function calls over the web)

How ASP.NET works When.NET is installed, IIS is configured to look for files with the.aspx extension and to use the ASP.NET module (aspnet_isapi.dll) to handle them. ASP.NET parses the.aspx file and arranges it in a predefined class definition and generates an asp.net page object. The page object generates html that is sent back to IIS and then the browser. NOTE: only.aspx files are parsed (if it is pure html don’t save it as an aspx file as it will slow down the server.

ASP.NET samples Page directives: VB.NET code declarations ……….. Message.aspx Inserting ASP.NET code Example Line1: First HTML Line Line2: Second HTML Line Line3: Third HTML Line Note this has no asp code so better to use.html extension

Message2.aspx Sub Page_Load() Response.Write ("First ASP.NET Line ") Response.Write ("Second ASP.NET Line ") Response.Write ("Third ASP.NET Line ") End Sub Inserting ASP.NET code Example Line1: First HTML Line Line2: Second HTML Line Line3: Third HTML Line

Message3.aspx html> Inserting ASP.NET code Example Line1: First HTML Line Line2: Second HTML Line Line3: Third HTML Line Sub Page_Load() Response.Write ("First ASP.NET Line ") Response.Write ("Second ASP.NET Line ") Response.Write ("Third ASP.NET Line ") End Sub

Render or inline code block – interweave1.aspx Interweaving ASP.NET code and HTML Example Line1: First HTML Line ") %> Line2: Second HTML Line ") %> Line3: Third HTML Line ") %> NOT RECOMMENDED.

Interweave2.aspx A Server control script language="VB" runat="server"> Sub Page_Load() Message.Text="The ASP.NET line" End Sub Inserting ASP.NET code Example First HTML Line Second HTML Line

Page class events Page_init Page_load Server_Controls Page_prerender Page_Unload

ASP.NET Vs PHP FeaturePHPASP.NET HTMLYes CSSYes ‘php Templates’YesUserControls ServerControls (buttons,grids etc) NoYes JavascriptYesYes + Validation controls Database ConnYes Cookies & Sessions Yes VIEWSTATENoYes POSTBACKNoYes

Examples quickstart – webforms –Intro4 shows VIEWSTATE –Intro6 shows a click event –Intro7 shows a usercontrol with a calander –Intro8 shows a db connection –Intro9 & 10 show asp.net templates –Intro11shows validation controls –Intro13 shows code behind pages Server directives eg trace and debug –tracetrace

The lab environment. IIS server – interdev.csse.monash.edu.au/cse2030…. Each student has write access to their own directory on interdev (Sstudentnum) URL: ntnum/message.aspx Alternative to.Net is webmatrixwebmatrix Interdev is not accessible outside Monash network.