'NET and 'NET Framework

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.NET and .NET Framework

• What is .NET?
• What is .NET Framework?
• What are .NET Technologies?
• Application Platforms on .NET
• .NET vs. JAVA

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What is .NET?

• Microsoft .NET is a set of Microsoft software
  technologies
• for connecting information, people, systems, and
  devices. It
• enables a high level of software integration
  through the use
• of Web servicessmall, discrete, building-block
  applications
• that connect to each other as well as to other,
  larger
• applications over the Internet.
• A development platform interfaces, components
  and tools
• to develop software. The biggest change in the
  Microsoft
• platform since Windows NT replaced DOS.

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What is .NET Framework

• The .NET Framework provides the foundation for
  building and running .NET based application
• The .NET Framework consists of two components
• Common language runtime (CLR)
• .NET Framework class library
• Any language that conforms to the common language
  specification (CLS) can run on the common
  language runtime

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Common Language Runtime (CLR)

• The common language runtime manages the execution
  of code and provides services to simplify the
  development process
• CLR support for multiple languages, and a managed
  environment where common services, such as
  garbage collection and security are automatically
  provided

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.NET Framework Class Library

• The .Net Framework class library exposes features
  of the runtime and provides a library of classes
  that are accessed by all Web, windows-based and
  XML Web service applications
• .NET Framework class library includes
• ADO.NET (ActiveX Data Objects)
• ASP.NET (Active Server Pages)
• XML Web Services
• User Interfaces

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How The .Net Framework Works

• When you compile an application in Visual Studio
  .NET, it is translated into the runtimes common
  language, Microsoft Intermediate Language (MSIL).
  After the application is compiled, the runtime
  manages the execution of the application.
• The runtime includes a feature called
  just-in-time (JIT) compilation that translates
  the MSIL code into the machine language of the
  system on which the application will run

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How The .Net Framework Works
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Compiling and Executing Managed Code
Source Code
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.NET Technologies

• The .NET Framework
• With support for XML Web services
• Visual Studio.NET
• Supporting Visual Basic.NET, C, C, and JScript
• .NET My Services
• The .NET Enterprise Servers
• BizTalk Server 2000
• SQL Server 2000
• Commerce Server 2000

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Application Platforms Today
Browser Apps
Web Services Apps
Other Apps
Local Apps
Operating System
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The .NET Framework
Browser Apps
Web Services Apps
Other Apps
Local Apps
Windows
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The Competition The Java Environment
Browser Apps
Web Services Apps
Other Apps
Local Apps
Windows, Solaris, Linux, others
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.NET and Java Application Platforms

• .NET
• The .NET Framework
• Java
• Java application servers
• Products include
• IBM WebSphere Application Server
• BEA WebLogic Application Server
• Sun iPlanet Application Server
• Oracle Application Server
• Many others

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Inside a .NET Framework Application

• Every .NET Framework application relies on the
  CLR
• Common language runtime provides
• A common set of data types
• An intermediate language (MSIL) generated from
  all CLR-based programming languages
• A common mechanism for packaging compiled code
• Software that uses the CLR is called managed code

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Data Types in the CLR

• The CLR defines the Common Type System (CTS)
• All languages built on the CLR use the CTS
• Types are divided into two categories
• Value types
• Relatively simple types
• Allocated on the stack
• Reference types
• More complex types
• Allocated on the heap
• Destroyed through garbage collection

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Illustrating the CTS
Object
ValueType
Class
Interface
Byte
Int16
Single
UInt16
Double
UInt32
Array
Char
Int32
UInt64
Int64
String
Enum
Decimal
Delegate
Structure
Others
Boolean
Others


Reference Types
Value Types
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.NET and Java Runtime Environments

• .NET Framework
• Intermediate language is MSIL
• Provides just-in-time (JIT) compilation
• There is no interpreter in the CLR
• Java
• Intermediate language is bytecode
• Original design targeted interpretation
• Java VMs with JIT compilation are now also used

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Compilation in the .NET Environment
Class X Class Y Class Z
Source Code
MSIL Code for Class X
MSIL Code for Class Y
MSIL Code for Class Z
Metadata for Classes X, Y and Z
DLL or EXE
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The Structure of a .NET Framework Application
App Domain
Assembly
Class Y
Class Z
Class X
Method 1
Method 1
Method 1
Method 2
Method 2
Method 2
Method 3
Method 3
Method 4
Stack
Heap
Metadata for Classes X, Y and Z
Garbage Collector
JIT Compiler
Loader
Common Language Runtime
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Languages in .NET

• All .NET languages are built on the CLR
• All have much in common
• Visual Studio.NET supports
• C
• Visual Basic.NET
• C
• JScript
• Other languages will also be available

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An Interface and Class in C

• public interface ICalc
• int add(int x, int y)
• int subtract(int x, int y)
• public class Calculator ICalc
• int add(int x, int y)
• return x y
• int subtract(int x, int y)
• return x y

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An Interface and Class in Java

• public interface ICalc
• int add(int x, int y)
• int subtract(int x, int y)
• public class Calculator implements ICalc
• int add(int x, int y)
• return x y
• int subtract(int x, int y)
• return x y

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A Simple Comparison Similarities

• Similarities
• C-derived syntax
• Object-oriented
• Single implementation inheritance
• Multiple interface inheritance
• Built-in immutable String type

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A Simple Comparison Differences

• C adds
• Attributes
• Properties
• Direct memory access
• In unsafe code

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C

• A new language designed expressly for the .NET
  Framework (That is what Microsoft says)
• Syntax based on C/C
• Built on the CLR, with
• Support for the CTS
• Classes
• Inheritance
• Method overloading

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VB.NET

• Redesigned from the ground up for the CLR, with
• Full support for the CTS
• All other CLR features
• Classes
• Inheritance
• Method overloading
• Its functionally very much like C

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VB.NET Example

• Class Compute
• Implements IMath
•  
• Function Factorial(ByVal F As Integer) As
  Integer
• Implements IMath.Factorial
• Dim I As Integer
• Dim Result As Integer 1
• For I 2 To F
• Result Result I
• Next
• Return Result
• End Function
•  

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C

• C with Managed Extensions can be used to create
  .NET applications
• Extends the base language
• Managed C provides
• Garbage collection
• Built-in support for interfaces, properties, and
  events
• Access to all other CLR features
• C can still create native binaries if desired
• All other Visual Studio.NET languages produce
  only MSIL

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.NET Framework Class Library

• Accessible from any language targeting the CLR
• Written in C
• Organized into namespaces
• All of which are below the System namespace
• Contains
• ASP.NET
• ADO.NET
• Windows Forms

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A Small Part of the System Namespace
System

Int32, String,
Data
Windows
Web
XML
EnterpriseServices
UI
Services
Forms
XmlDocument,
ServicedComponent,



Connection, DataSet,
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.NET vs. Java Standard Libraries

• .NET Framework class library
• Defined by Microsoft
• Somewhat Windows-oriented
• Organized into a hierarchy of namespaces
• J2SE, J2EE
• Defined by Sun and the Java Community Process
• Not bound to any operating system
• Defined as packages and interfaces

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Conclusion

• The .NET Framework includes
• The CLR
• Supporting multiple programming languages
• The .NET Framework class library
• Both .NET and Java will survive I guess
• Which makes both of them better
• .NET is the future of application development on
  Windows