ASP.NET Active Server Pages ASP.NET is a server-side technology for developing web applications...
-
Upload
helena-dalton -
Category
Documents
-
view
218 -
download
0
description
Transcript of ASP.NET Active Server Pages ASP.NET is a server-side technology for developing web applications...
ASP .NET – Active Server Pages
ASP.NET is a server-side technology for developingweb applications based onthe .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”>