Chapter 1

Working with Microsoft ASP.NET 


Overview

•  Introducing ASP.NET
• Creating Web Forms
• Adding ASP.NET Code to a Page
• Handling Page Events
• Discussion: ASP vs. ASP.NET

Microsoft® Active Server Pages (ASP) technology is widely used to create

dynamic Web sites and applications. However, ASP has several limitations,

such as the need for redundant and lengthy coding to accomplish simple goals.

To overcome these limitations of ASP, Microsoft has developed a new

technology called Microsoft ASP.NET, which is a part of the Microsoft .NET

strategy for Web development. ASP.NET is a unified Web development

platform that provides the services necessary for developers to build enterpriseclass

Web applications.

In this module, you will learn about the main features of ASP.NET and

discover the differences between ASP and ASP.NET. You will also learn about

server controls and see how to add server -side script to an ASP.NET page.

After completing this module, you will be able to:

• Identify the main features of ASP.NET.
• Identify the differences between ASP and ASP.NET.
• Describe the working model of ASP.NET.
• Describe the architecture of server controls.
• Add a Hypertext Markup Language (HTML) server control to a page.
• Access the properties and methods of server controls in code.
• Add event handlers for page events.
• Use the IsPostback property to handle postback forms.

Introducing ASP.NET

• The Microsoft .NET Framework
• ASP.NET Features
• Animation: ASP.NET Execution Model

In this section, you will read an overview of the Microsoft .NET Framework

and see how ASP.NET fits in. Next, you will learn about the various features of

ASP.NET and see a working model. You will also learn about the main

differences between ASP and ASP.NET.

The Microsoft .NET Framework

The Microsoft .NET Platform provides all of the tools and technologies that are

needed to build distributed Web applications. It exposes a consistent, languageindependent

programming model across all tiers of an application, while providing seamless interoperability with and easy migration from existing technologies.

The Microsoft .NET Platform is composed of several core technologies:

• The Microsoft .NET Framework
• The Microsoft .NET Building Block Services
• The Microsoft .NET Enterprise Servers
• Microsoft Visual Studio ® .NET
• Microsoft Windows. NET

The Microsoft .NET Framework is a set of technologies that is integral to the

Microsoft .NET Platform. It provides the basic building blocks for developing

Web applications and services. The Microsoft .NET Framework includes the

following components:

• Common Language Runtime
• Base class library
• Data
• Web forms and Web services
• WinForms

Common Language Runtime

The Common Language Runtime provides the programming interface between

the Microsoft .NET Framework and the programming languages available for

the Microsoft .NET Platform. It simplifies application development, provides a

robust and secure execution environment, supports multiple languages, and

simplifies application deployment and management. The run time loads and

runs code written in any run time-aware programming language. Code that

targets the run time is called managed code. Managed code simply means that

there is a defined contract of cooperation between natively executing code and

the run time itself. Responsibility for tasks like creating objects, making method

calls, and so on is delegated to the run time, which enables the run time to

provide additional services to the executing code.

Base Classes and Libraries

The Microsoft .NET Framework includes classes that encapsulate data

structures, perform Input/Output (I/O), provide access to information about a

loaded class, and provide a way to invoke security checks. It also includes

classes that encapsulate exceptions and other helpful functionality such as data

access, server-side user interface (UI) projections, and rich graphical user

interface (GUI) generation. The Microsoft .NET Framework provides both

abstract base classes and class implementations derived from those base classes.

You can use these derived classes “as is” or derive your own classes from them.

The Microsoft .NET Framework classes are named using a dot-syntax naming

scheme that connotes a naming hierarchy. This technique is used to group

related classes logically together so that they can be searched and referenced

more easily. A grouping of classes is called a namespace. For example, a

program can use classes in the System.Data.SqlClient namespace to read data

from a SQL Server database.

The root namespace for the Microsoft .NET Framework is the System
namespace.


Data

Microsoft ADO.NET is the next generation of ActiveX® Data Object (ADO)

technology. ADO.NET provides improved support for the disconnected

programming model and also provides rich Extensible Markup Language

(XML) support. ADO was created to provide data services to traditional client

applications that were tightly coupled to the database; consequently it was not

effective for Web applications. ADO.NET was created with the characteristics

of Web applications in mind.

Web Forms and Web Services

ASP.NET is a programming framework built on the Common Language

Runtime that can be used on a server to build powerful Web applications.

ASP.NET Web forms provide an easy and powerful way to build dynamic user

interfaces. ASP.NET Web services provide the building blocks for constructing

distributed Web-based applications. Web services are based on the Simple

Object Access Protocol (SOAP) specification.

Win Forms

For applications that are based on Microsoft Windows®, the Microsoft .NET

Framework provides the System.Windows.Forms namespace to create the user

interface. You can use System.Windows.Forms to do rapid application design

(RAD). It provides inheritance in the same client user interface library. You can

build components by using inheritance and then aggregate them by using a form

designer such as Microsoft Visual Basic ®.

ASP.NET Features

• Multiple Language Support
• Increased Performance

                Compiled code

                 Cache

• Classes and Namespaces
• Server Controls
• Web Services

ASP.NET is more than just the next version of ASP. It is a totally re-architected

technology for creating dynamic, Web-based applications. ASP pages use

the .asp extension and ASP.NET pages use the extension .aspx.

                                                                                                                                  

Note  Both ASP and ASP.NET pages can be used on the same Web site.

Existing ASP pages will still work along with new ASP.NET pages; they do not

need to be converted into ASP.NET pages.

                                                                                                                                   

ASP.NET, with a host of new features, allows developers to write cleaner code

that is easy to reuse and share. ASP.NET boosts performance and scalability by

offering access to compiled languages. Some of the main features of ASP.NET

are described below.

Multiple Language Support

ASP.NET provides a true language-neutral execution framework for Web

applications.

You can currently use over 20 languages to build .NET applications. Microsoft

has compilers for Visual Basic, Microsoft Visual C#™ , Microsoft Visual C++®,

and Microsoft JScript®. Third-party vendors are writing .NET compilers for

Cobol, Pascal, Perl, and Smalltalk, among others.

The labs and the sample code in this course will use Visual Basic.

Increased Performance

In ASP.NET, code is compiled. When you request a page for the first time, the

run time compiles the code and the page itself, and keeps a cached copy of the

compiled result. When you request the page the second time, the cached copy is

used. This results in greatly increased performance because, after this first

request, the code can run from the much faster compiled version and the content

on the page does not need to be parsed again.

Classes and Namespaces

ASP.NET includes a range of useful classes and namespaces. Namespaces are

used as an organizational system— a way to present program components that

are exposed to other programs and applications. Namespaces contains classes.

Namespaces are like class libraries and can make writing Web applications 

easier. Some of the classes included with ASP.NET are HtmlAnchor,

HtmlControl, and HtmlForm, which are included within the

System.Web.UI.HtmlControls namespace.

                                                                                                                              
Note  Namespaces may change between the Beta 2 and the final release
versions of ASP.NET.
                                                                                                                              

Server Controls

ASP.NET provides several server controls that simplify the task of creating

pages. These server controls encapsulate common tasks that range from

displaying calendars and tables to validating user input. They automatically

maintain their selection states and expose properties, methods, and events for

server-side code, thereby providing a clean programming model.

For more information about using server controls, see Module 2, “Using Web

Controls,” in Course 2063B, Introduction to Microsoft ASP.NET.

Web Services


A Web service is an application delivered as a service that can be integrated
with other Web services by using Internet standards. ASP.NET allows you to
use and create Web services.


For example, a company can assemble an online store by using the Microsoft
Passport service to authenticate users, a third-party personalization service to
adapt Web pages to each user’s preferences, a credit-card processing service, a
sales tax service, package-tracking services from each shipping company, and
an in-house catalog service that connects to the company’s internal inventory
management applications.


Web services provide the building blocks for constructing distributed Webbased
applications. ASP.NET files have an .aspx extension and Web services
have an .asmx extension. The technologies are similar; however, instead of
outputting HTML, a Web service outputs a computer-readable answer to the
input it receives.


For more information about Web services, see Module 6, “Using Web
Services,” in Course 2063B, Introduction to Microsoft ASP.NET.

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