7/30/2019 Unit 1 Dotnet

1/25

How Did We Get to .NET?

The Evolution of Web Applications First generation of Web applications -non-interactive

content (HTML static content)

Second generation of Web applications - scalable

back-end and a richer User Interface. (DCOM, ASP,

CGI, Cold Fusion, dynamic content)

Third generation of Web applications (.NET) - using

Web protocols and XML to allow better integration

between services on the Web

7/30/2019 Unit 1 Dotnet

2/25

Why the Move to .NET?

DCOM works fine on an Intranet, however:

DCOM does not go through firewalls

Requires too many open TCP/IP portsRequires Stateful connections

Platform dependent

Portals provide services however:

Non-standard interfaces

Hard to integrate with other applications

Not desi ned to use outside the sco e of the ortal

7/30/2019 Unit 1 Dotnet

3/25

.NETWhat Is It?

Software platform

Language neutral

In other words:.NET is not a language (Runtime and a library for

writing and executing written programs in any

compliant language)

7/30/2019 Unit 1 Dotnet

4/25

What Is .NET

.Net is a new framework for developingweb-based and windows-based applications

within the Microsoft environment.

The framework offers a fundamental shift inMicrosoft strategy: it moves application

development from client-centric to server-

centric.

7/30/2019 Unit 1 Dotnet

5/25

.NETWhat Is It?

Operating System + Hardware

.NET Framework

.NET Application

7/30/2019 Unit 1 Dotnet

6/25

Base Class Library

Common Language Specification

Common Language Runtime

ADO.NET: Data and XML

VB

VC++

VC#

V

isualStudio.NET

ASP.NET: Web Services

and Web Forms

JScript

Windows

Forms

Framework, Languages, And Tools

7/30/2019 Unit 1 Dotnet

7/25

The .NET Framework.NET Framework Services

Common Language Runtime

Windows Forms

ASP.NETWeb Forms

Web Services

ADO.NET, evolution of ADO

Visual Studio.NET

7/30/2019 Unit 1 Dotnet

8/25

Common Language Runtime

(CLR)

CLR works like a virtual machine in executing

all languages.

All .NET languages must obey the rules and

standards imposed by CLR. Examples:

Object declaration, creation and use

Data types,language libraries

Error and exception handling

Interactive Development Environment (IDE)

7/30/2019 Unit 1 Dotnet

9/25

Common Language Runtime

Development Mixed language applications

Common Language Specification (CLS)

Common Type System (CTS)

Standard class framework Automatic memory management

Consistent error handling and safer execution

Potentially multi-platform

Deployment Removal of registration dependency

Safetyfewer versioning problems

7/30/2019 Unit 1 Dotnet

10/25

Common Language Runtime

Base Class Library

Common Language Specification

Common Language Runtime

Data and XML

VB C++

VisualStudio

.NET

WebServices

JScript

UserInterface

7/30/2019 Unit 1 Dotnet

11/25

Component of CLR

Class Loader

IL to NativeCompilers

CodeManager

GarbageCollector

Security Engine Debug Engine

Type Checker Exception Manager

Thread Support COM Marshaler

Base Class Library Support

7/30/2019 Unit 1 Dotnet

12/25

The CLR provides a number of services that include:

. Code management(loading and execution).

.Verification of type safety.

. Conversion of IL to native code.

. Access to metadata.

. Managing memory for managed objects.

. Enforcement of code access security.

.Support for developer services.

7/30/2019 Unit 1 Dotnet

13/25

Common Language RuntimeMultiple Language Support

CTS is a rich type system built into the CLR

Implements various types (int, double, etc)

And operations on those types.The CTS performs the following functions:

1. Establishes a framework that enables cross-language integration,type safety, and high

performance code execution.2. Provides an object-oriented model that supports

the complete implementation of manyprogramming languages.

7/30/2019 Unit 1 Dotnet

14/25

Common Language RuntimeMultiple Language Support

CTS is a rich type system built into the CLR

Implements various types (int, double, etc)

And operations on those types CLS is a set of specifications that language and

library designers need to follow

This will ensure interoperability between

languages

7/30/2019 Unit 1 Dotnet

15/25

Common Type System

CTS is a rich type system built into the CLR

Implements various types (int, double, etc)

And operations on those typesOR

The common type system defines how types aredeclared,used, and managed in the runtime.

CTS performs the following functions:1.Establishes a framework that enables cross-language

integration,type safety, and high performance codeexecution.

2. Provides an object-oriented model that supports thecomplete implementation of many programming language

7/30/2019 Unit 1 Dotnet

16/25

Common Language Specification

CLS is the collection of the rules and

constraints that every language(that seeks to

achieve .NET compatibility)must follow.

OR

The common language specification(CLS)is a

collection of rules and restrications that allow

interoperation between languages.

7/30/2019 Unit 1 Dotnet

17/25

Compilation in .NET

Code in VB.NET Code in C#Code in another

.NET Language

VB.NET compiler C# compilerAppropriate

Compiler

IL(Intermediate

Language) code

CLR just-in-time

execution

7/30/2019 Unit 1 Dotnet

18/25

Intermediate Language (IL) .NET languages are not compiled to machine code. They

are compiled to an Intermediate Language (IL).

CLR accepts the IL code and recompiles it to machine

code. The recompilation is just-in-time (JIT) meaning it is

done as soon as a function or subroutine is called.

The JIT code stays in memory for subsequent calls. In

cases where there is not enough memory it is discarded

thus making JIT process interpretive.

7/30/2019 Unit 1 Dotnet

19/25

MICROSOFT INTERMEDIATE

LANGUAGE

A .NET Languages source code first compile

to the MSIL code, and send to the CLR that

converts to machine code.

MSIL is similar to JAVA Byte code. A Java

program is compiled into Java Byte code by a

Java compiler, the class file is then sent to

JVM which converts it into the host machine

language .

7/30/2019 Unit 1 Dotnet

20/25

JUST-IN-TIME(JIT) COMPILER

JIT compiler turns MSIL into native code,

which is CPU-specific code that runs on the

same computer architecture as the JIT

compiler. Because the CLR supplies a JIT

compiler for each supported CPU architecture,

developers can write a set of MSIL that can be

JIT-compiled and run on computers withdifferent architectures.

7/30/2019 Unit 1 Dotnet

21/25

GARBAGE COLLECTION

Garbage Collection is a mechanism that allows

the computer to detect when an object can no

longer be accessed and then automatically

releases the memory used by that object.

7/30/2019 Unit 1 Dotnet

22/25

UNIFIED CLASEES(Base class

Library)

The Unified Classes is a set of classes that

provide useful functionality to CLR

programmers.

.NET framework comes with a single class

library.And thats all programmers whether

they write the code in C# or VB.NET or J#,it

doesnt matter, just use the .NET class library.

7/30/2019 Unit 1 Dotnet

23/25

Class Libraries

The .NET Framework has an extensive set of class libraries.This includes classes for :

Data Access:High Performance data access classes forconnecting to SQL Server or any other OLEDB provider.

XML Supports:Next generation XML support that goesfar beyond the functionality of MSXML.

Directory Services: Support for accessing Active

Directory.

Regular Expression:Support for above and beyondthat found in Perl %.

Queuing Supports:Provides a clean object-orientedset of classes for working with MSMQ

7/30/2019 Unit 1 Dotnet

24/25

USER AND PROGRAM INTERFACE The .NET framework provide the following tools for managing user

and application interfaces:

Window Forms: Window forms are used to

create GUI applications for windows.

Web Forms: Web Forms are used to createweb applications.

Console Application: Console application are

used to create command line orientedapplications

Web Services: Web Services provides tools

for developing web application.

7/30/2019 Unit 1 Dotnet

25/25