Thursday, February 7, 2008

ASP.NET - HTML Server Controls

HTML server controls are HTML tags understood by the server.

HTML elements in ASP.NET files are, by default, treated as text. To make these elements programmable, add a runat="server" attribute to the HTML element. This attribute indicates that the element should be treated as a server control. The id attribute is added to identify the server control. The id reference can be used to manipulate the server control at run time.

ASP.NET - Server Controls

ASP.NET has solved the "spaghetti-code" problem described above with server controls.

Server controls are tags that are understood by the server.

There are three kinds of server controls:

HTML Server Controls - Traditional HTML tags
Web Server Controls - New ASP.NET tags
Validation Server Controls - For input validation

Classic ASP

Active Server Pages (ASP) has been around for several years. With ASP, executable code can be placed inside HTML pages.

Previous versions of ASP (before ASP .NET) are often called Classic ASP.

ASP.NET is not fully compatible with Classic ASP, but most Classic ASP pages will work fine as ASP.NET pages, with only minor changes.

How Does it Work?

Fundamentally an ASP.NET page is just the same as an HTML page.

An HTML page has the extension .htm. If a browser requests an HTML page from the server, the server sends the page to the browser without any modifications.

An ASP.NET page has the extension .aspx. If a browser requests an ASP.NET page, the server processes any executable code in the page, before the result is sent back to the browser.

The ASP.NET page above does not contain any executable code, so nothing is executed. In the next examples we will add some executable code to the page to demonstrate the difference between static HTML pages and dynamic ASP pages.

Wednesday, February 6, 2008

ASP.NET vs Classic ASP

The previous examples didn't demonstrate any differences between ASP.NET and Classic ASP.

As you can see from the two latest examples there are no differences between the two ASP and ASP.NET pages.

In the next chapters you will see how server controls make ASP.NET more powerful than Classic ASP.

Classic ASP

Active Server Pages (ASP) has been around for several years. With ASP, executable code can be placed inside HTML pages.

Previous versions of ASP (before ASP .NET) are often called Classic ASP.

ASP.NET is not fully compatible with Classic ASP, but most Classic ASP pages will work fine as ASP.NET pages, with only minor changes.

New in ASP.NET

Better language support
Programmable controls
Event-driven programming
XML-based components
User authentication, with accounts and roles
Higher scalability
Increased performance - Compiled code
Easier configuration and deployment
Not fully ASP compatible

The Microsoft .NET Framework

The .NET Framework is the infrastructure for the Microsoft .NET platform.

The .NET Framework is an environment for building, deploying, and running Web applications and Web Services.

Microsoft's first server technology ASP (Active Server Pages), was a powerful and flexible "programming language". But it was too code oriented. It was not an application framework and not an enterprise development tool.

The Microsoft .NET Framework was developed to solve this problem.

.NET Frameworks keywords:

Easier and quicker programming
Reduced amount of code
Declarative programming model
Richer server control hierarchy with events
Larger class library
Better support for development tools

The .NET Framework consists of 3 main parts:

Programming languages:

C# (Pronounced C sharp)
Visual Basic (VB .NET)
J# (Pronounced J sharp)

Server technologies and client technologies:

ASP .NET (Active Server Pages)
Windows Forms (Windows desktop solutions)
Compact Framework (PDA / Mobile solutions)

Development environments:

Visual Studio .NET (VS .NET)
Visual Web Developer

This tutorial is about ASP.NET.

What is ASP.NET?

ASP.NET is a server side scripting technology that enables scripts (embedded in web pages) to be executed by an Internet server.

ASP.NET is a Microsoft Technology
ASP stands for Active Server Pages
ASP.NET is a program that runs inside IIS
IIS (Internet Information Services) is Microsoft's Internet server
IIS comes as a free component with Windows servers
IIS is also a part of Windows 2000 and XP Professional

Tuesday, February 5, 2008