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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..
Language changes between VB and VB.NET:
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Language changes between VB and VB.NET:
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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Language changes between VB and VB.NET:
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