1. Evolution of .NET
•Around 1995, java was becoming popular because of its platform-
independent approach and sun’s policy to distribute it free.
• Later in 2002, Sun released the enterprise edition of java i.e J2EE that is
a programming platform under java platform to develop and execute
distributed multitier architecture java application.
•As a result microsoft was loosing its market .
•Thus, to capture the market Microsoft started a project was called Next
Generation Windows Services (NGWS). It took more than three years to
develop the product and the result was what we know now as .NET.
•.NET Framework 1.0 released on 13 February 2002, is the first release
of the .NET Framework.
•This version of the .NET Framework is also a part of the first released of
Visual Studio .NET which is know as Visual Studio .NET 2002.
•Later its second release of known as Visual Studio .NET 2003.
•Then Visual Studio .NET 2005, 2008, 2010.

2. Comparison of J2EE and .NET
Key Features .NET J2EE
Type of technology .NET is a product J2EE is a standard.
Operating System One operating System Multiple Operating Systems.
support
Programming It supports Programming Language like It supports only a single
Language. VB.NET, C#, J#, and so on. programming language, java
Vendor Support Supported by single vendor It is supported by multiple
( Microsoft) vendors
Interpreter During the first compilation process, the Java code is compiled to
source code is compiled to IL which is bytecode by JRE and is
machine independent and during the interpreted or compiled to
second process the IL is executed using machine code.
JIT compiler and CLR transforms it into
machine code. Thus any code in .NET is
compiled twice.
Dynamic web pages In .Net it is ASP.NET In J2EE it’s JSP.
Graphical user Microsoft Visual Studio IDE. No other Many Java IDE’s and tools
Interface IDE support .NET.
Database ADO.NET JDBC

3. Objective of .Net Framework
• To provide object oriented environment to
develop application.
• To provide a code execution environment
that provides safety of code execution.
• It simplifies deployment and versioning.
• It eliminates the issues faced by scripted
environment with respect to
performance.
• To provide a common programming model
where the choice of programming langu.
becomes a matter of choice.

4. Architecture of Microsoft .NET
• .Net framework is made up of two
components – Common Language
Runtime (CLR) and the .NET Framework
Class Library (FCL).
• The CLR is basis of .Net Framework and
provides various services that application
can use.
• The runtime suppose to be an agent that
manages code at execution time, provides
core services, such as memory
management and remoting.

5. • It also encourage security, and robustness by
implementing safety and other type of code
accuracy.
• Since code management is a basic principle of
the runtime, code that target runtime is known as
managed code and the code that does not target
the runtime is known as unmanaged code.
• The following diagram shows the relationship of
common language runtime and class library to
your application and to overall system. (.NET
Framework architecture)

6. VB C++ C# Jscript ----
Common Language Specification (CLS)
Web Application Windows Application
ADO.NET and XML
Base Class Library
Common Language Runtime (CLR)
Operating System

7. • You can see Operating System at the base. It
can be any Microsoft windows platform that
support Visual Studio .NET.
• CLR provides its services to application by
providing a standard set of library classes called
as Class Library.
• The other development platform and
applications are built on top of base Class
Library.
• Language Compliers that need to generate code
for CLR must bound to a common set of
specifications that are establish by Common
Language Specification (CLS)

8. Common Language Runtime
• CLR is the platform on which applications are
hosted and executed.
• It is used to manage memory, thread execution,
code execution, code safety, verification,
compilation, and other system services.
• Since the runtime manages the execution of
your code, code that works on the CLR is called
managed code.
• The CLR also supports a set of services that the
application can use to access various resources
like arrays, collections, operating System folders
etc.

9. • Interoperability between managed and
unmanaged code enables developers to
continue to use COM components and DLLs.
• The managed environment of the runtime
eliminates many common software issues. For
example the runtime automatically releases the
object when they are no longer being used.
• This automatic memory management resolves
the memory leaks and invalid memory
references.
• Since runtime supports code access security
and code robustness, it implements a strict type
and code verification infrastructure called
Common Type System (CTS). It ensures that all
managed code is self-describing.

10. • The programmer can write application in
the development language of their choice
such as C#, VB, ASP.NET etc.
• Managed code is never interpreted. A
feature called Just-in-time compiling
enables to run the managed code in the
native machine language of the system on
which it is executing.

11. Advantages of CLR
• Enhance performance and productivity.
• The power of using components develop in other
languages.
• Using CLR, you can experience extensible type provided
by class Library.
• Access to new features and characteristics of language
like inheritance, interface and overloading for object-
oriented Programming.
• It allows to create multithreaded, Scalable application.
• Structured exception handling and custom attributes are
supported by the CLR.

12. Compiler and Loader:
CLR uses JIT and compiles the IL code to machine code and then
executes . CLR also determines depending on platform what is optimized way of
running the IL code.
Code verification and optimization:
This ensures proper code execution and type safety while the code runs.
It prevents the source code to perform illegal operation such as accessing invalid
memory location etc.
Memory management and garbage collection:
CLR automatically manages memory thus eliminating memory leaks.
When object are not referred GC automatically releases those.
Code Access Security:
CAS grants rights to the program depending on security
configuration of the machine. Example the program has rights to edit or create a
new file but the security configuration of machine does not allow the program to
delete a file.
CAS will take care that the code runs under the environment of the
machine security configuration

13. Type Safety and Security
• Type-safe code accesses only the
memory locations it is authorized to
access .
• For example, type-safe code cannot read
values from another object's private fields.
It accesses types only in well-defined,
allowable ways.
• This process is skipped if the code has
permission to bypass verification

14. Managed code
• The code whose execution is managed by CLR is known
as Managed code.
• It refers to a contract of cooperation between natively
executing code and runtime.
• This contract determines that at any point of execution,
the runtime may stop an executing CPU and retrieve
information specific to the current CPU instruction
address.
• Managed code are compiled to IL not to machine code
that could run directly on your computer.
• The IL is kept in a file called an assembly along with
metadata to describe all of the entry points, classes,
methods, and attributes of the code that you have
created.

15. • CLR first loads and verifies the assembly to
approve IL. While assembly runs, the runtime
continues to provide services such as security,
memory management, threading and so on.
• Where as unmanaged code compiled directly to
the m/c code and runs to the m/c where you
compiled it.
• It does not get services like security or memory
management from an invisible runtime.
• Most recent unmanaged application get
operating system services through COM calls.

16. Execution Process
• The managed execution process includes the following steps:
– Choosing a compiler
– Compiling your code to MSIL.
– Compile MSIL to native code.
– Execute your code.

17. • Choosing a compiler:
– You can choose one or more language compiler targeting the
runtime such as VB,C#, Visual C++.
• Compiling your code to MSIL:
– When your compile source code into MSIL , it generated
metadata. MSIL is a CPU independent set of instructions that
can be efficiently changed to native code.
– The instruction for loading, storing, initializing, arithmetic and
logical operations , Control flow, direct memory access,
exception handling, calling methods on object and so many
other operations are included in MSIL.
– At the time of creating MSIL, the compiler also generates the
metadata that describes the types, Reference or value type, in
your code along with each type definition, the signature of each
type’s members, members referenced by your code, and other
data that the runtime uses at execution time.
– Metadata are basically information about the compiled classes.
– The MSIL and metadata are contained in a portable executable
file, which is standard format for processor –specific execution.

18. • Compiling MSIL to Native code:
– While executing your application JIT translate the MSIL into
native code. When this compilation is performed, the code must
be passed through a verification process that examines to
check whether the code is type safe or not. It means that it is
known to access the authorized memory location.
– JIT compilation allows the fact that some code might never get
called during execution. Instead of using time and memory to
convert all IL to native code, it converts the IL as needed during
the execution and stores the resulting native code so that it is
accessible for subsequent call.
– The runtime also supports another way of compilation known as
install-time code generation. It converts all the MSIL into native
code in single shot by taking larger unit of code at a time. The
entire assembly is converted into native code at the installation
time only.

19. • Executing your code:
– The method must be compiled to processor
specific code before running.
– Each method for which MSIL is there is JIT
compiled, when it called for first time and then
run.
– Next time when the method is run, the existing
JIT compiled native code is run

20. Common Type System
• It provides certain guidelines for declaring,
using, managing type at runtime.
• It is also an integral part of runtime for
supporting cross-language communication
• Following are the functions performed by CTS
– It helps in cross-language communication, Type
Safety, high performance execution.
– It supports object- oriented model for implementation
of different programming language.
– It specifies the guidelines for different language to
follow and ensuring interaction between object of
different language.

21. Classification of Types
• CTS is classified into two general
catagories
– Value Type:
• Value type contains its data directly and their
objects are allocated on stack . Value type can be
built-in, user-defined, enumeration.
– Reference Type:
• It contains data’s memory address and allocated
on heap. They can be pointer type, self-describing
type or interactive type.

23. Meta Data
• A metadata describes a program in the form of binary
information, which is stored in a CLR portable
Executable File or in memory.
• When compilation of the code take place, the metadata
is inserted into one part of the file, while the code is
converted into MSIL and inserted into the other part of
the file.
• Every type and member is described inside the
metadata.
• When code is in run mode, the CLR loads the metadata
into memory and find information about the code’s
classes and members and so on.

24. The Metadata includes following
information
• It contains assembly information like its identity,
name, version, culture, public key, the types,
other references assembly, and security
permission.
• It contains information about types, like name,
visibility, base class, and interface used, and
members( methods, field, properties, events).
• It maintains attribute information which modifies
types and members.
• The metadata is stored along with the code.

25. Assembly
• Assemblies are packed into units containing programs and
libraries.
• An Assembly contains self-describing binary which can be
either Dynamic Link Library (DLL) or Executable (EXE).
• It also contains a collection of types, such as classes,
interface, structure and so on.
• A single assembly can contain multiple files or single file can
contain multiple assembly.
• Assembly contains the code which the CLR executes.
• Assembly can be of two types-static and dynamic .
• Static assembly include interface, classes and resources like
bitmap, JPEG files and so on.
• These assemblies are stored in PE files on disk.
• Using .NET framework you can create dynamic assemblies,
which run directly from the memory and are not stored on disk
before execution.
• But after they have been executed, you can save them on the
disk.

26. Assembly Contents
• A static assembly consist of the following
4 elements.
– Manifest
– Type metadata
– MSIL code that implements the type
– Set of resources
Group these elements can be done in various
way. You can group all the elements in a
single physical file or all the elements of
assembly can be stored in various files.

27. Manifest
• Every Assembly contains data that describes how the elements
within that assembly are related to each other.
• The manifest contains the assembly metadata needed for
providing assembly’s version, security identity.
• The manifest can be stored in a PE file within MSIL or in Standalone
file that contains only manifest information.
• The following information stored in assembly manifest
– Assembly name
– Version number
– List of Files in Assembly
– Information on referenced assembly
• It contain the list of other assembly that are referenced by the assembly
– Type reference information
• Information used by runtime to map a type reference that contains its
declaration and implementation
– Strong name information
• It contains Public key from the publisher if the assembly has given strong
name.
– Culture
• It provides information about language the assembly supports.

28. Global Assembly Cache
• It is the Central place for registering assemblies, which
can be later shared by different applications on the
computer.
• One thing to note is that you should make the
assemblies sharable by registering them in the GAC only
when needed. Otherwise keep the assembly private.
• It is not mandatory to install the assemblies in GAC in
order to make them accessible to the COM or
unmanaged code.
• You can deploy an assembly in the GAC using following
way
– Use of installer which is designed to work with GAC.
– Use of GAC tool know as Gacutil.exe
– Use windows explorer for dragging assemblies into cache.

29. Strong Name Assemblies
• A strong name contains the assembly’s identity, which is
nothing but information about its name, version number,
culture information, Public key and digital signature.
• Strong name can be provided to an assembly using
Microsoft Visual Studio .NET.
• By providing strong name to the assembly you can
ensure that an assembly is globally unique.
• Strong name fulfill following requirements:
– Strong name provides uniqueness.
– Strong name ensures that a version of assembly
comes from the same publisher that created the
version of the application.
– Strong names facilitate integrity check, which ensures
that the contents of the assembly have not been
changed since it was last built.

30. Private and Shared Assembly
• When an assembly is used by a single application then it
is called as Private assembly.
• For example you have created a DLL which contains
information about your business logic and it can be used
by your client application not by any other application.
• So in order to run the application your DLL must be
included in the same folder in which client application is
installed . This makes the assembly private to your
application.
• Now suppose the DLL, which you have created needs to
be reused in different application.
• You can do it by placing the DLL in GAC instead of each
client application having its own copy of DLL.
• Assembly like this is called as shared Assembly.

31. Application Domain
• CLR creates an application domain and
ensure that the crashing of an application
domain does not affect the functioning of
another application domain.
• Typically, we use process boundaries to
isolate application running on the same
computer.
• Each application we create is loaded into
a separate process. The applications are
separated from each other because
memory addresses are process-relative.

32. Framework Class Library (FCL)
• The FCL is made up of a hierarchy of namespace that
expose classes, structures, interface, enumeration and
delegates that gives you access to these resources.
• The namespace is logically defined by its functionality.
For e.g System.Data namespace contains all the
functionality available for accessing database.
• This namespace is further broken down into
System.Data.Olebd which expose specific functionality
for accessing OLEDB data sources.
• It is approximately 20,000 classes in FCL, all logically
grouped in a hierarchical manner.
• FCL is huge library of reusable types, it is object-oriented
library , you can use it like any other library, you can also
extend the FCL towards your application needs and then
write your application code

33. Features of .NET
• 64-bit platform support:
– Now a days there is great demand for 64 bit
computers, as they enable the creation of
application that can run fast and take
advantage of more memory than is available
to 32 bit application.
– 64-bit application enables user to build
managed code libraries. It supports 32-bit
application to run on 64-bit
• Access Control List Support:
– .net developer can now use ACL feature to
grant or revoke the permission to access a
resources on a computer

34. • Authenticated Streams:
– Applications can employ two new classes to
authenticate and to provide secure information
transmitted between a client and server. They are
NegotiateStream and SslStream.
– These authenticated stream classes supports mutual
authentication, data encryption, and data signing.
– The NegotiateStream class uses the Negotiate
security protocol for authentication.
– Using NegotiateStream class you can do following:
• Request Server authentication
• Send the client’s certificate to the server
• Encrypt or sign data before transmitting.
– SslStream class uses secure socket layer (SSL)
security protocol for authentication.

35. • COM Interop Services Enhancement:
– To support interoperability with COM improvements has been
made to classes and tools.
• Console Class Addition:
– Console class represent the standard input, output, and error
streams for console applications. Console class contains
methods that read individual character or entire lines from the
console.
• Data Protection API:
– It includes the ability to encrypt password and connection string
on the server.
– You can also encrypt block of memory on the computers running
windows server 2003 or later operating System.
• Distributed Computing:
– In the System.Net namespace, the support is added to FTP
client requests, caching of HTTP resources, automatic proxy
discovery and obtaining network traffic and statistical
information.

36. • Generics and Generic Collection:
– Generics allows you to create flexible and reusable
code. These are language feature, which act as
templates to allow classes, structure, interface,
methods, delegates to be declared with generic type
parameter rather than specific types. Later when
generic is used, it defines the actual types.
– The generic classes and methods are provided within
several namespace like System.Namespace and
System.Collections.Generic.
– Generics are supported basically in three languages
visual basic, C#, and C++.
• Globalization:
– Globalization refers to the process with which an
application or software will be designed and
developed to make it run across all platforms and all
sites with minimum or no modification to application.

37. • .NET Framework Remoting
– Remote means any object which executes outside the
application domain.
– .Net framework remoting supports IPV6 address.
– It enables developers to write scalable distributed application.
– .Net remoting is an architecture , which enables communication
between different application domains or processes using
different transportation protocol, serialization formats, object
lifetime schemes and mode of object creation.
• ClickOnce Deployment:
– Click Once Deployment permits you to deploy self-updating
windows application that can be installed and run as easily as
web Application.
– It overcomes following three issues in deployment
• Difficulties in updating Application
– To update the application user have to reinstall the entire application,
This feature update the application automatically.
• Impact to the user’s Computer:
– While publishing your application using click once deployment, each
application is self- contained and cannot interfere with other application.
• Security Permission:
– It allows non-administrative users to install and grant only those code
access security permission necessary for the application.