What is .NET Framework?

Defining the .NET Framework

The .Net FrameWork is
-The Microsoft .NET Framework is a platform for building, deploying and XML Web Services and applications.

-It provides the necessary classes, namespaces and assemblies to create such applications.

-the ability to solve the challenges of deployment and operation of Internet-scale applications.

-The .NET Framework is used by all Microsoft languages including Visual C#, VB.Net,Visual J#, and Visual C++.

-It is a collection of many small technologies integrated as a single large technology.such that very powerful application can be developed which can be used anywhere anytime.

-A programming infrastructure created by Microsoft for building and

-running application and services that use .Net technologies.such as

-desktop application and Webservices.

-A software development environment.

-A run time engine for managed code.

-A platform designed for Internet-distributed software

A First look at Managed code Sample code
Hello.vb
Imports System.Windows.Forms
Imports System.Drawing

Class MyForm
    Inherits Form

Public Shared Sub Main()
      Application.Run(New My Form())
 End Sub
    Protected Overloads Overrides Sub OnPaint(ByVal e As PaintEventArgs)
        e.Graphics.DrawString("Hello World!", NewFont("Arial",35)Brushes.Blue,10,100)
 End Sub
End Class

What is CLR ?
The CLR (Common language runtime) is..
-CLR is .Net run time execution engine ,it's like virtual machine in java. It converts the MSIL code to Machine level language. It provides lot of service to .Net frame work.
-Code execution and loading
-Application memory support
-Code access security.
-Memory Management objects.
-Exception handling.
-Code interoperability between unmanaged code and Data.
It includes CLS and CTS
-Conversion of MSIL to native code.
-Developer support like Profiling and Debugging..etc.Access to Metadata.
-Manages .NET Code (such as VB.Net applications)
-Provides features such as memory management, thread management, object type safety, security, etc.
-Is a part of the .NET Framework

What is managed code ?
-Managed code
-Code that targets the CLR
-Any .NET Language, including C#, Visual Basic, C++, Java, Cobol, etc.

What is memory management ?
The memory management is..

The CLR manages memory for managed code
--All allocations of objects and buffers made from a Managed Heap
=Unused objects and buffers are cleaned up automatically through Garbage Collection
--Some of the worst bugs in software development are not possible with managed code
--Leaked memory or objects
--References to freed or non-existent objects
=Reading of uninitialized variables
=Pointerless environment

What is The Framework Class Library ?
-A huge collection of reusable types
Classes, interfaces, enumerations and structures
-For use by any managed code
Including code written in any managed programming language
-Types for
-Common tasks such as collections, file IO, memory and thread management
-GUI and window manipulation
Web form and web service applications
-Totally object oriented toolbox for developers
-Ships as part of the .NET Framework

Using FCL

Types are arranged in a hierarchy of Namespaces
-A type’s full name includes its namespaces
-Form class is actually System.Windows.Forms.Form
Use ‘imports’ to indicate namespaces in source code
Assembly references are necessary for many types
-The SDK documentation is critical for using SDK types
-Includes descriptions
-Often includes useful code samples
-Indicates namespaces and assemblies for types

Namespace
-It is a physical representation of dll.
-The .net framework class library is available as a collection of namespaces.
-Namespace contain types, such as classes and enumerations, which is use in a program.
-When you want use a Windows form, you must use the System.windows.forms.
-Here ‘system’ includes essential classes and base classes that define commonly used data types events and event handlers,interfaces,attributes,exceptions and so on.

Asp.Net technology
-It is a technology which is used for designing Web forms and Web services.
-Asp. net is an important component of the .net framework.asp.net provides advanced capabilities, such as efficient database access and easy to use application and session stae capabilities.
-Asp. net application can b created using .net language.

Types of Managed Applications
-Common application
-GUI or windowed applications (Windows. Forms)
Console applications or command line apps
-Web applications (ASP.net)
-Web forms applications
Web services
-Scripted code
-Applications like word processors or database servers can host the CLR
-Use any managed language (C#, VB, etc.) as a script or macro language