ASP.NET Programming

What Is Programming?

Simply put, programming is the process of creating a set of instructions for the computer to follow. These instructions are written in a language or languages which people can understand, and then "compiled" (literally, translated) into machine language, or interpreted by the computer from reading a script. HTML is a programming language, as are JavaScript and VBScript. The "syntax" of a programming language consists of the various language elements, conventions, and operators that are used to write the instructions.

Procedural and Object-Oriented Programming

The first item of business is to identify the 2 basic kinds of programming that exist, and how each one fits into the overall picture:

Procedural Programming was the first kind of programming to develop, and involves a relatively simple way of doing things. In procedural programming, the computer is given a set of instructions which it executes, and then waits for input, which it reacts to by executing another set of instructions, and so on.

There are 3 basic elements of procedural programming:

• Sequence - The order in which instructions are executed is the sequence of the programming. This is far more important than it might seem, but having things in the proper sequence is essential.
• Selection - If/else conditional statements and other forms of selection form the second element. This is how a program makes and reacts to choices.
• Iteration - The use of "loops" and other forms of repetitive sets of instructions forms the last building block of procedural programming.

Object Oriented Programming came along later, with the advent of multi-tasking operating systems such as Windows. In point of fact, procedural programming is at the heart of all programming, including object-oriented, but because certain kinds of objects have many characteristics in common (such as windows, for example), it is more convenient to treat them as objects, rather than as sets of instructions. An object has properties, methods, and event handlers.

• Properties - Properties of an object are the characteristics which define how the object behaves. In a web page, for example, the page itself has certain properties, which are defined in the body tag, such as the background color, style source page, etc.
• Methods - Methods are actually blocks of instructions that can be executed by an object itself, and each object has its' own set of methods. A simple example of this would be the submit() method of a form. When You click on the Submit button of a form, or invoke the submit() method for a form with a JavaScript command, the form is submitted using the form's submit() method.
• Event Handlers - An "event" is when something happens, either something that the user has done, or something the program itself has done, or another program has done. The simplest example I can think of for an event is using the form example above. When you click the "Submit" button, you have generated an event, and the event handler is the set of instructions which is programmed to execute when that event occurs. Because of the nature of multi-tasking systems like Windows, one is never sure where the next event is going to come from, so event handlers are designed to react to events in the appropriate manner. Each object has its' own event handlers, built into the object itself.

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

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