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Dot Net

Pawan Kumar Jasuja


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Chapter 1 - Facts about Dot Net

Introduction to Dot Net. Chapter 2 - Dot Net Framework

Just In Time Compilers

Chapter 3 - Different types of file in Web Project

Chapter 4 - VB.NET Features

Chapter 5 - Language Diff between VB & VB.NET


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Facts about Dot Net

General Facts

Microsoft put their best men at work for a secret project called Next

Generation Windows Services (NGWS),under the direct supervision of

Mr. Bill Gates. The outcome of the project is what we now know as

.NET.

Microsoft has countered Java's Write once, Run anywhere premise,

with Write many languages, Run on one Microsoft platform.


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Introduction to Dot Net

What is .Net?

It is a platform neutral framework.

Is a layer between the operating system and the programming

language.

It supports many programming languages, including VB.Net,C#

etc.

Net provides a common set of class libraries, which can be accessed from

any .net based programming language.There will not be separate set of

classes and libraries for each language. If you know any one .net language,

you can write code in any .net language!!


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Introduction to Dot Net

In future versions of Windows, .net will be freely distributed as part

of operating system and users will never have to install .net

separately.

What it is Not ?

.Net is not an operating system.

.Net is not a programming language.

".Net is a framework"


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Dot Net Framework :


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Just-In-Time Compliers:

The Just-In-Time (JIT or JITter) compiler converts the MSIL (Microsoft Intermediate

Language) code into the native code (CPU Specific code). The .NET runtime/Common

Language Runtime (CLR) ships three different classes of JITters.

Econo-JIT: This compiler converts the MSIL code into native code without any

optimizations.

Standard-JIT: This compiler takes the MSIL code and verified and optimize it. So this

compiler requires lot of resources like, time to compile, larger memory footprint, etc.

PreJIT: This is based on the Main JIT and it works like the traditional compilers rather

than Just-In-Time compilers. This compiler is used at the time of installation and it

reduce start up time.


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VB.NET Features:

Object Oriented Programming language. Support of inheritance,

overloading, interfaces, shared members and constructors.

Supports all CLS features such as accessing and working with .NET

classes, interaction with other .NET languages, meta data support,

common data types, and delegates.

Multithreading support.

Structured exception handling.

Abstraction, Encapsulation, Polymorphism, and Inheritance are four basic

properties of an object-oriented language. VB 6.0 supports all of these

properties but not Inheritance. Now VB.NET supports Inheritance. This

brings VB.NET in object-oriented languages category such as C++.

Continue.


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VB.NET Features:

Overloading

VB.NET supports method overloading using the overload keyword.

Using this keyword, you can declare same method names with

different arguments.

Scope of a Class MembersBesides Private and Public, VB.NET introduces few new keywords.The

following keywords are used to define scope of a class member.

Private Scope is limited to the defined class only.

Public Object can be called from the outside of the class.

Friend: Scope is limited to the application in which class is defined.

Protected Available to the class and its derived classes.

Protected FriendAvailable to the class, the application, and the derived

classes.


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Language changes between VB and VB.NET:

Data Type changes:

Data Type VB 6.0 VB.NET

Integer 16 bit size 32 bit size

Long 32 bit size 64 bit size

Currency Currency was used to store

large floating point values.

Replaced with decimal,

supports

Variant Can hold any type of data. Replaced with Object type.

Can hold any type of data.

Provide better results.

Date Date used to stored as

double.

Introduces DateTime data

type designed to store date

in different formats.


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VB.NET supports multiple variable declarations in the same line.:

Dim s1,s2 as String

VB.NET supports declaration and initialization on same line:

Dim s1 As String = Pawan

VB.NET supports block level variables. Variables declared within a block have

scope only limited to that block :

For I= 1 to 10

Dim a as String

-----

----

Next

Continue..



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Improved Type Safety

In VB 6.0, you can specify As Any for any type of argument with the

declare statement when you declare a reference to an external procedure

As Any keywords disable type checking and allow any data type to be

passed in or returned. VB.NET does not support the Any keyword. You

must specifically declare the data type of every argument and of the

return.

Variant Vs. Object

In VB 6.0, Variant data type can store data of any type in a variable of

type Variant. In VB.NET, Object can be used to hold data of any type.

Array

Lower bound for Array is 0 and you cant change this.

We can have maximum 32 dimensions in an Array.

Continue


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Arithmetic Operators

VB.NET now supports like shortcut operators. You can use same shortcuts for

any operator such as *, /, |, and &.

a+=5, a*=5 etc.

Strings

VB.NET doesnt support fixed length strings.

ByVal is default Argument Type

In VB 6.0, ByRef was default type when you call a function or sub. That

means all changes would reflect in the variable you pass to a parameter. This

behavior is changed in VB.NET. Now the default argument type is ByVal. If

you dont specify the argument type, compiler takes it as ByVal.


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Different types of file in Web Project:

.aspxThe files having this extension are basically ASP.NET web pages. These

basically contains the User Interface

.ascx

This file is called the ASP.NET User Control. A user control file is a simply

text file which is saved with the extension "ascx". It does not contain html,

body, and frame tag..asmx

The files having extension .asmx are called ASP.NET Web Services

web.config

this file is basically XML-based configuration file for ASP.NET application. this

file basically handles security, state management, and memory management

issues

global.asa

This file is basically used to define the global variables and to response to

global events

Continue..


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Different types of file in Web Project:

disco or .vsdiscoThese are special discovery files used to find web services

.vb or .cs

These files are basically code-behind files and are used to separate the code

from user interface(.aspx)

.sln, .suo

These are files which are basically used by Visual Studio .NET to group

together projects. These files are only used during development

Continue..


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THANK YOU

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