Florida Gulf Coast University Software Project in Computer Networks CNT 4104 Dr. Janusz Zalewski Florida Gulf Coast University
ASP .NET – Active Server Pages
ASP.NET is a server-side technology for developing web applications based on the .NET Framework.
Terminology Reminder: web application – same as dynamic website.
ASP.NET has been created in response to such technologies as CGI, PHP, etc., that allow creating dynamic webpages ASP.NET allows use of multiple languages (C#, VB, others) ASP.NET pages are compiled, not interpreted
Essentially, ASP.NET requires using: Windows, although .NET Framework has been ported to other operating systems, as well Microsoft’s Internet Information Services (IIS) server (although a small server named Cassini exists for hobbyists)
Microsoft SQL Server is also required, if one needs a webpage to interact with a database (required in any serious web development)
Technical details: web pages are text files with .aspx extension web files should be placed in the directory C:\Inetpub\wwwroot files cannot be opened locally from Explorer, only via the web server default.aspx is a default page
Structure of an ASP.NET page: directives code declaration blocks code render blocks ASP.NET server controls server side comments literal text and HTML tags.
Role of the directives: control how the page is compiled allow importing classes specify page caching in a browser assist in debugging. Directives start with <%@ and end with %> Example of a directive: <%@ Page Language=“C#” %>
Code declaration blocks help separate the application logic from HTML contents. The application logic defines variables, subroutines, functions, etc.
Example of a code declaration block: <script runat=”server”> void mySub() { // Code placed here } </script>
Code render blocks define inline code and inline expressions. Inline code render blocks execute one or more statements and are placed inside HTML code delimited by <% … %> Inline expression render blocks display values of variables/methods.
Example of a code render block: <% string Title=”text”; %> Example of inline expression render block: <%= Title %>
ASP.NET server controls are central to every ASP.NET page represent page’s dynamic elements usually must reside within a <form runat=“server”> tag fall into 3 categories: ASP.NET controls, HTML controls, and web user controls.
Server side comments allow including text, which will not be processed by ASP.NET. They are included in special type of brackets: <%-- comments go here --%>
Literal text and HTML tags provide the structure for presenting dynamic data, give a page the right format, which the browser can understand.
Sample code <%@ Page Language=”C#” %> <!DOCTYPE html PUBLIC ”-//W3C//DTD XHTML 1.0 Strict//EN” ”http://www.w3.org/TR/xtml1/DTD/html1-strict.dtd”> <HTML> <HEAD> <TITLE>Sample Page</TITLE> <SCRIPT runat=”server”> void Page_Load() { messageLabel.Text = ”Hello World”; } </SCRIPT> </HEAD> <BODY> <FORM runat=”server”> <P> <ASP:Label id=”messageLabel” runat=”server” /> <P> <%-- Declare title as string and set it --%> <% string Title=”From code render block”; %> <%= Tiltle %> </FORM> </BODY> </HTML>
Summary All of the dynamic portions of the web pages in ASP.NET are usually contained within code render blocks or controls located inside a tag: <form runat=”server”>