What is DOTNET?

Contrary to general belief .NET is not a single technology. Rather it is a set of

Technologies that work together seamlessly to solve your business problems.

Kind of applications you can develop:

What type of applications can I develop?

When you hear the name .NET, it gives a feeling that it is something to do only

with internet or networked applications. Even though it is true that .NET provides

solid foundation for developing such applications it is possible to create many

other types of applications. Following list will give you an idea about various

types of application that we can develop on .NET.

1. ASP.NET Web applications: These include dynamic and data driven browser

based applications.

2. Windows Form based applications: These refer to traditional rich client

applications.

3. Console applications: These refer to traditional DOS kind of applications like

batch scripts.

4. Component Libraries: This refers to components that typically encapsulate

some business logic.

5. Windows Custom Controls: As with traditional ActiveX controls, you can

develop your own windows controls.

6. Web Custom Controls: The concept of custom controls can be extended to

web applications allowing code reuse and modularization.

7. Web services: They are “web callable” functionality available via industry

standards like HTTP, XML and SOAP.

8. Windows Services: They refer to applications that run as services in the

background. They can be configured to start automatically when the system

boots up.

.NET Framework SDK

You can develop such varied types of applications. That’s fine. But how? As with

most of the programming languages, .NET has a complete Software Development

Kit (SDK) - more commonly referred to as .NET Framework SDK - that

provides classes, interfaces and language compilers necessary to program for

.NET. Additionally it contains excellent documentation and Quick Start tutorials

that help you learn .NET technologies with ease. Good news is that - .NET

Framework SDK is available FREE of cost. You can download it from the MSDN

web site. This means that if you have machine with .NET Framework installed

and a text editor such as Notepad then you can start developing for .NET right

now!

Development Tools

If you are developing applications that require speedy delivery to your customers

and features like integration with some version control software then simple

Notepad may not serve your purpose. In such cases you require some Integrated

Development Environment (IDE) that allows for Rapid Action Development

(RAD). The new Visual Studio.NET is such an IDE. VS.NET is a powerful and

flexible IDE that makes developing .NET applications a breeze. Some of the

features of VS.NET that make you more productive are:

- Drag and Drop design

- IntelliSense features

- Syntax highlighting and auto-syntax checking

- Excellent debugging tools

- Integration with version control software such as Visual Source Safe (VSS)

- Easy project management

Note that when you install Visual Studio.NET, .NET Framework is automatically

installed on the machine.

.NET Redistributable

In order to run application developed using .NET Framework the machine must

have certain ‘runtime’ files installed. They are collectively called as .NET

redistributable. This is analogous to traditional Visual Basic applications that

required Visual Basic runtime installed on target computers. .NET redistributable

provides one redistributable installer that contains the common language runtime

(more on that later) and Microsoft .NET Framework components that are

necessary to run .NET Framework applications. The redistributable is available as

a stand-alone executable and can be installed manually or as a part of your

application setup.

You can download .NET redistributable at

http://msdn.microsoft.com/downloads/default.asp?url=/downloads/sample.asp?url

=/msdn-files/027/001/829/msdncompositedoc.xml

More technical information about .NET redistributable can be found at

http://msdn.microsoft.com/library/default.asp?url=/library/enus/

dnnetdep/html/dotnetfxref.asp

Note that if you have installed .NET Framework SDK, there is no need of

installing redistributable separately. Also, note that there is difference between

.NET Framework SDK and .NET redistributable in terms of purpose and tools

and documentation supplied. .NET Framework SDK is intended to ‘develop’

applications where as .NET redistributable is intended to ‘run’ .NET applications.

Features of .NET

Now that we know some basics of .NET, let us see what makes .NET a wonderful

platform for developing modern applications.

• Rich Functionality out of the box

.NET framework provides a rich set of functionality out of the box. It contains

hundreds of classes that provide variety of functionality ready to use in your

applications. This means that as a developer you need not go into low level details

of many operations such as file IO, network communication and so on.

• Easy development of web applications

ASP.NET is a technology available on .NET platform for developing dynamic

and data driven web applications. ASP.NET provides an event driven

programming model (similar to Visual Basic 6 that simplify development of web

pages (now called as web forms) with complex user interface. ASP.NET server

controls provide advanced user interface elements (like calendar and grids) that

save lot of coding from programmer’s side.

• OOPs Support

The advantages of Object Oriented programming are well known. .NET provides

a fully object oriented environment. The philosophy of .NET is – “Object is

mother of all.” Languages like Visual Basic.NET now support many of the OO

features that were lacking traditionally. Even primitive types like integer and

characters can be treated as objects – something not available even in OO

languages like C++.

• Multi-Language Support

Generally enterprises have varying skill sets. For example, a company might have

people with skills in Visual Basic, C++, and Java etc. It is an experience that

whenever a new language or environment is invented existing skills are outdated.

This naturally increases cost of training and learning curve. .NET provides

something attractive in this area. It supports multiple languages. This means that

if you have skills in C++, you need not throw them but just mould them to suit

.NET environment. Currently four languages are available right out of the box

namely – Visual Basic.NET, C# (pronounced as C-sharp), Jscript.NET and

Managed C++ (a dialect of Visual C++). There are many vendors that are

working on developing language compilers for other languages (20+ language

compilers are already available). The beauty of multi language support lies in the

fact that even though the syntax of each language is different, the basic

capabilities of each language remain at par with one another.

• Multi-Device Support

Modern lift style is increasingly embracing mobile and wireless devices such as

PDAs, mobiles and handheld PCs. . . .NET provides promising platform for

programming such devices. .NET Compact Framework and Mobile Internet

Toolkit are step ahead in this direction.

• Automatic memory management

While developing applications developers had to develop an eye on system

resources like memory. Memory leaks were major reason in failure of

applications. .NET takes this worry away from developer by handling memory on

its own. The garbage collector takes care of freeing unused objects at appropriate

intervals.

• Compatibility with COM and COM+

Before the introduction of .NET, COM was the de-facto standard for

componentized software development. Companies have invested lot of money and

efforts in developing COM components and controls. The good news is – you can

still use COM components and ActiveX controls under .NET. This allows you to

use your existing investment in .NET applications. .NET still relies on COM+ for

features like transaction management and object pooling. In fact it provides

enhanced declarative support for configuring COM+ application right from your

source code. Your COM+ knowledge still remains as a valuable asset.

• No more DLL Hell

If you have worked with COM components, you probably are aware of “DLL

hell”. DLL conflicts are a common fact in COM world. The main reason behind

this was the philosophy of COM – “one version of component across machine”.

Also, COM components require registration in the system registry. .NET ends this

DLL hell by allowing applications to use their own copy of dependent DLLs.

Also, .NET components do not require any kind of registration in system registry.

• Strong XML support

Now days it is hard to find a programmer who is unaware of XML. XML has

gained such a strong industry support that almost all the vendors have released

some kind of upgrades or patches to their existing software to make it “XML

compatible”. Currently, .NET is the only platform that has built with XML right

into the core framework. .NET tries to harness power of XML in every possible

way. In addition to providing support for manipulating and transforming XML

documents, .NET provides XML web services that are based on standards like

HTTP, XML and SOAP.

• Ease of deployment and configuration

Deploying windows applications especially that used COM components were

always been a tedious task. Since .NET does not require any registration as such,

much of the deployment is simplified. This makes XCOPY deployment viable.

Configuration is another area where .NET – especially ASP.NET – shines over

traditional languages. The configuration is done via special files having special

XML vocabulary. Since, most of the configuration is done via configuration files,

there is no need to sit in front of actual machine and configure the application

manually. This is more important for web applications; simply FTPing new

configuration file makes necessary changes.

• Security

Windows platform was always criticized for poor security mechanisms. Microsoft

has taken great efforts to make .NET platform safe and secure for enterprise

applications. Features such as type safety, code access security and role based

authentication make overall application more robust and secure.

Coming Next…

By the time you must have got idea about what .NET is and what it can do for you. You

probably will have installed .NET on your machine waiting eagerly to try hands on it.

However, before you go into the code level details, it is essential that you firmly

understand certain fundamentals. In the next section we will demystify some intrinsic

concepts and features of .NET framework.

@2

What type of Programmers we are ?

System Programmers: One who programs directly for a given hardware.

Ex: Device Drivers etc..

Application Programmers: One Who Programs Applications used by People for their requirements.

Ex: Calculator, Calendar, MS Office packages, Accounting Packages etc..

.NET if for Application Programmers not for the System Programmers.

Definitions:

Platform: is an environment for developing and executing applications.

Framework: is ready to use collection of classes and interfaces used for developing a particular type of application.

Understanding the .NET Platform and its layers

Here in this section we will be covering what the .NET Platform is made up of

and we will define its layers. To start, .NET is a framework that covers all the layers

of software development above the Operating System. It provides the richest level of

integration among presentation technologies, component technologies, and data

technologies ever seen on Microsoft, or perhaps any, platform. Secondly, the entire

architecture has been created to make it easy to develop Internet applications, as it

is to develop for the desktop.

Constituents of .NET Platform

The .NET consists of the following three main parts

• .NET Framework – a completely re-engineered development environment.

• .NET Products – applications from MS based on the .NET platform, including

Office and Visual Studio.

• .NET Services – facilitates 3rd party developers to create services on the .NET

Platform.

The Common Language Runtime (CLR)

At the base is the CLR. It is considered as the heart of the .NET framework. .NET

applications are compiled to a common language known as Microsoft Intermediate

Language or “IL”. The CLR, then, handles the compiling the IL to machine language,

at which point the program is executed.

The CLR environment is also referred to as a managed environment, in which

common services, such as garbage collection and security, are automatically

provided.