The Microsoft .NET Framework is a software component that can be added to or is included with Microsoft Windows operating system. It provides a large body of pre-coded solutions to common program requirements, and manages the execution of programs written specifically for the framework. The .NET Framework is a key Microsoft offering, and is intended to be used by most new applications created for the Windows platform.
The pre-coded solutions that form the framework's class library cover a large range of programming needs in areas including: user interface, data access, database connectivity, cryptography, web application development, numeric algorithms, and network communications. The functions of the class library are used by programmers who combine them with their own code to produce applications.
Programs written for the .NET Framework execute in a software environment that manages the program's runtime requirements. This runtime environment, which is also a part of the .NET Framework, is known as the Common Language Runtime (CLR). The CLR provides the appearance of an application virtual machine, so that programmers need not consider the capabilities of the specific CPU that will execute the program. The CLR also provides other important services such as security mechanisms, memory management, and exception handling. The class library and the CLR together compose the .NET Framework. The framework is intended to make it easier to develop computer applications and to reduce the vulnerability of applications and computers to security threats.
It is included with Windows Server 2003 and Windows Vista, and can be installed on most older versions of Windows.
Design goals and principal features
Microsoft .NET Framework was designed with several intentions:
* Interoperability - Because interaction between new and older applications is commonly required, the .NET Framework provides means to access functionality that is implemented in programs that execute outside the .NET environment. Access to COM components is provided in the System.Runtime.InteropServices and System.EnterpriseServices namespaces of the framework, and access to other functionality is provided using the P/Invoke feature.
* Common Runtime Engine - Programming languages on the .NET Framework compile into an intermediate language known as the Common Intermediate Language, or CIL (formerly known as Microsoft Intermediate Language, or MSIL). In Microsoft's implementation, this intermediate language is not interpreted, but rather compiled in a manner known as just-in-time compilation (JIT) into native code. The combination of these concepts is called the Common Language Infrastructure (CLI), a specification; Microsoft's implementation of the CLI is known as the Common Language Runtime (CLR).
* Language Independence - The .NET Framework introduces a Common Type System, or CTS. The CTS specification defines all possible datatypes and programming constructs supported by the CLR and how they may or may not interact with each other. Because of this feature, the .NET Framework supports development in multiple programming languages. This is discussed in more detail in Microsoft .NET Languages.
* Base Class Library - The Base Class Library (BCL), part of the Framework Class Library (FCL), is a library of types available to all languages using the .NET Framework. The BCL provides classes which encapsulate a number of common functions, including file reading and writing, graphic rendering, database interaction and XML document manipulation.
* Simplified Deployment - Installation of computer software must be carefully managed to ensure that it does not interfere with previously installed software, and that it conforms to increasingly stringent security requirements. The .NET framework includes design features and tools that help address these requirements.
* Security - .NET allows for code to be run with different trust levels without the use of a separate sandbox.
A design goal of the .NET Framework was to support platform independence[citation needed]. That is, a program written to use the framework should run without change on any type of computer for which the framework is implemented. However, Microsoft has only implemented the full .NET framework on the Windows operating system. Microsoft and others have implemented portions of the framework on non-Windows systems, but to date these implementations are neither complete nor widely used, so full cross-platform support has not been achieved.
[edit] .NET Framework architecture
Visual overview of the Common Language Infrastructure (CLI)
Visual overview of the Common Language Infrastructure (CLI)
[edit] Common Language Infrastructure (CLI)
Main article: Common Language Infrastructure
The important component of the .NET Framework lies within the Common Language Infrastructure, or CLI. The purpose of the CLI is to provide a language-agnostic platform for application development and execution, including, but not limited to, components for exception handling, garbage collection, security, and interoperability. Microsoft's implementation of the CLI is called the Common Language Runtime, or CLR. The CLR is composed of four primary parts:
* Common Type System (CTS)
* Common Language Specification (CLS)
* Just-In-Time Compiler (JIT)
* Virtual Execution System (VES)
[edit] Assemblies
Main article: .NET assembly
The intermediate CIL code is housed in .NET assemblies, which for the Windows implementation means a Portable Executable (PE) file (EXE or DLL). Assemblies are the .NET unit of deployment, versioning and security. The assembly consists of one or more files, but one of these must contain the manifest, which has the metadata for the assembly. The complete name of an assembly contains its simple text name, version number, culture and public key token; it must contain the name, but the others are optional. The public key token is generated when the assembly is created, and is a value that uniquely represents the name and contents of all the assembly files, and a private key known only to the creator of the assembly. Two assemblies with the same public key token are guaranteed to be identical. If an assembly is tampered with (for example, by hackers), the public key can be used to detect the tampering.
[edit] Metadata
Main article: .NET metadata
All CIL is Self-Describing through .NET metadata. The CLR checks on metadata to ensure that the correct method is called. Metadata is usually generated by language compilers but developers can create their own metadata through custom attributes. Metadata also contain all the information about assembly.
--> The Base Class Library , sometimes incorrectly referred to as the Framework Class Library (FCL) (which is a superset including the Microsoft.* namespaces), is a library of classes available to all languages using the .NET Framework. The BCL provides classes which encapsulate a number of common functions such as file reading and writing, graphic rendering, database interaction, XML document manipulation, and so forth. The BCL is much larger than other libraries, but has much more functionality in one package.
[edit] Security
.NET has its own security mechanism, with two general features: Code Access Security (CAS), and validation and verification. Code Access Security is based on evidence that is associated with a specific assembly. Typically the evidence is the source of the assembly (whether it is installed on the local machine, or has been downloaded from the intranet or Internet). Code Access Security uses evidence to determine the permissions granted to the code. Other code can demand that calling code is granted a specified permission. The demand causes the CLR to perform a call stack walk: every assembly of each method in the call stack is checked for the required permission and if any assembly is not granted the permission then a security exception is thrown.
When an assembly is loaded the CLR performs various tests. Two such tests are validation and verification. During validation the CLR checks that the assembly contains valid metadata and CIL, and it checks that the internal tables are correct. Verification is not so exact. The verification mechanism checks to see if the code does anything that is 'unsafe'. The algorithm used is quite conservative and hence sometimes code that is 'safe' is not verified. Unsafe code will only be executed if the assembly has the 'skip verification' permission, which generally means code that is installed on the local machine.
[edit] Standardization and licensing
In August 2000, Microsoft, Hewlett-Packard, and Intel worked to standardize CLI and the C# programming language. By December 2001, both were ratified ECMA standards (ECMA 335 and ECMA 334). ISO followed in April 2003 (ISO/IEC 23271 and ISO/IEC 23270).
While Microsoft and their partners hold patents for CLI and C#, ECMA and ISO require that all patents essential to implementation be made available under "reasonable and non-discriminatory (RAND) terms." In addition to meeting these terms, the companies have agreed to make the patents available royalty-free.
However, this does not apply for the part of the .NET Framework which is not covered by the ECMA/ISO standard, which includes Windows Forms, ADO.NET, and ASP.NET. Patents that Microsoft holds in these areas may deter non-Microsoft implementations of the full framework.
[edit] Versions
Microsoft started development on the .NET Framework in the late 90s originally under the name of Next Generation Windows Services (NGWS). By late 2000 the first beta versions of .NET 1.0 were being released.
Version Name Version Number Release Date
1.0 Beta 1 1.0.????.0 2000-11
1.0 Beta 2 1.0.2914.0 2001-06-20
1.0 RTM 1.0.3705.0 2002-01-05
1.0 SP1 1.0.3705.209 2002-03-19
1.0 SP2 1.0.3705.288 2002-08-07
1.0 SP3 1.0.3705.6018 2004-08-31
1.1 RTM 1.1.4322.573 2003-04-01
1.1 SP1 1.1.4322.2032 2004-08-30
1.1 SP1 (Windows Server 2003 Version) 1.1.4322.2300 2005-03-30
2.0 RTM 2.0.50727.42 2005-11-07
3.0 RTM 3.0.4506.30 2006-11-06
3.5 Beta 2 3.5.20706.1 2007-07-26
[edit] .NET Framework 1.0
This is the first release of the .NET Framework. Released on February 13, 2002. It is available on its own as a redistributable package or in a software development kit. It is also part of the first release of Microsoft Visual Studio .NET (also known as Visual Studio .NET 2002).
[edit] .NET Framework 1.1
This is the first major .NET Framework upgrade. It is available on its own as a redistributable package or in a software development kit, and was published April 3, 2003. It is also part of the second release of Microsoft Visual Studio .NET (released as Visual Studio .NET 2003). This is the first version of the .NET Framework to be included as part of the Windows operating system, shipping with Windows Server 2003.
[edit] Changes since 1.0
* Built-in support for mobile ASP.NET controls. Previously available as an add-on for .NET Framework, now part of the framework.
* Security changes - enable Windows Forms assemblies to execute in a semi-trusted manner from the Internet, and enable Code Access Security in ASP.NET applications.
* Built-in support for ODBC and Oracle databases. Previously available as an add-on for .NET Framework 1.0, now part of the framework.
* .NET Compact Framework - a version of the .NET Framework for small devices.
* Internet Protocol version 6 (IPv6) support.
* Numerous API changes.
[edit] .NET Framework 2.0
Released with Visual Studio .NET 2005, Microsoft SQL Server 2005 and BizTalk 2006.
* The 2.0 Redistributable Package can be downloaded for free from Microsoft, and was published on 2006-01-22.
* The 2.0 Software Development Kit (SDK) can be downloaded for free from Microsoft.
* It is included as part of Visual Studio 2005 and Microsoft SQL Server 2005.
* Version 2.0 is the last version with support for Windows 2000.
* It shipped with Windows Server 2003 R2 (not installed by default).
[edit] Changes since 1.1
* Numerous API changes.
* A new hosting API for native applications wishing to host an instance of the .NET runtime. The new API gives a fine grain control on the behavior of the runtime with regards to multithreading, memory allocation, assembly loading and more (detailed reference). It was initially developed to efficiently host the runtime in Microsoft SQL Server, which implements its own scheduler and memory manager.
* Full 64-bit support for both the x64 and the IA64 hardware platforms.
* Language support for Generics built directly into the .NET CLR.
* Many additional and improved ASP.NET web controls.
* New data controls with declarative data binding.
* New personalization features for ASP.NET, such as support for themes, skins and webparts.
* .NET Micro Framework - a version of the .NET Framework related to the Smart Personal Objects Technology initiative more....
[edit] .NET Framework 3.0
Architecture of the .NET Framework 3.0
Architecture of the .NET Framework 3.0
.NET Framework 3.0, formerly called WinFX,[1] includes a new set of managed code APIs that are an integral part of Windows Vista and Windows Server 2008 operating systems. It is also available for Windows XP SP2 and Windows Server 2003 as a download. There are no major architectural changes included with this release; .NET Framework 3.0 includes version 2.0 of the Common Language Runtime.[2]
.NET Framework 3.0 consists of four major new components:
* Windows Presentation Foundation (WPF), formerly code-named Avalon; a new user interface subsystem and API based on XML and vector graphics, which uses 3D computer graphics hardware and Direct3D technologies. See WPF SDK for developer articles and documentation on WPF.
* Windows Communication Foundation (WCF), formerly code-named Indigo; a service-oriented messaging system which allows programs to interoperate locally or remotely similar to web services.
* Windows Workflow Foundation (WWF) allows for building of task automation and integrated transactions using workflows.
* Windows CardSpace (WCS), formerly code-named InfoCard; a software component which securely stores a person's digital identities and provides a unified interface for choosing the identity for a particular transaction, such as logging in to a website.
[edit] .NET Framework 3.5
This article or section contains information about computer software currently in development.
The content may change as the software development progresses.
* This version of the framework uses version 2.0 of the CLR (the same model as the use of CLR 2.0 in .NET Framework 3.0). However changes are applied to the installed CLR 2.0.
* Full support for .NET Framework 3.5 project types, as well as targeting .NET Framework 3.5 in builds, will be included in Visual Studio 2008.
Changes
* New language features in C# 3.0 and VB.NET 9.0 compiler
* C# 3.0 adds support for expression trees and lambda methods
* Extension methods
* Anonymous types with static type inference
* Language Integrated Query (LINQ) along with its various providers
o LINQ to Objects
o LINQ to XML
o LINQ to SQL
* Paging support for ADO.NET
* ADO.NET synchronization API to synchronize local caches and server side datastores
* Asynchronous network I/O API[3]
* Peer-to-peer networking stack, including a managed PNRP resolver[4]
* Managed wrappers for WMI and Active Directory APIs[5]
* Enhancements to the WCF and WF runtimes that let WCF work with POX and JSON data, as well as expose WF workflows as WCF services.[6]
* Support for HTTP pipelining and syndication feeds.[6]
The pre-coded solutions that form the framework's class library cover a large range of programming needs in areas including: user interface, data access, database connectivity, cryptography, web application development, numeric algorithms, and network communications. The functions of the class library are used by programmers who combine them with their own code to produce applications.
Programs written for the .NET Framework execute in a software environment that manages the program's runtime requirements. This runtime environment, which is also a part of the .NET Framework, is known as the Common Language Runtime (CLR). The CLR provides the appearance of an application virtual machine, so that programmers need not consider the capabilities of the specific CPU that will execute the program. The CLR also provides other important services such as security mechanisms, memory management, and exception handling. The class library and the CLR together compose the .NET Framework. The framework is intended to make it easier to develop computer applications and to reduce the vulnerability of applications and computers to security threats.
It is included with Windows Server 2003 and Windows Vista, and can be installed on most older versions of Windows.
Design goals and principal features
Microsoft .NET Framework was designed with several intentions:
* Interoperability - Because interaction between new and older applications is commonly required, the .NET Framework provides means to access functionality that is implemented in programs that execute outside the .NET environment. Access to COM components is provided in the System.Runtime.InteropServices and System.EnterpriseServices namespaces of the framework, and access to other functionality is provided using the P/Invoke feature.
* Common Runtime Engine - Programming languages on the .NET Framework compile into an intermediate language known as the Common Intermediate Language, or CIL (formerly known as Microsoft Intermediate Language, or MSIL). In Microsoft's implementation, this intermediate language is not interpreted, but rather compiled in a manner known as just-in-time compilation (JIT) into native code. The combination of these concepts is called the Common Language Infrastructure (CLI), a specification; Microsoft's implementation of the CLI is known as the Common Language Runtime (CLR).
* Language Independence - The .NET Framework introduces a Common Type System, or CTS. The CTS specification defines all possible datatypes and programming constructs supported by the CLR and how they may or may not interact with each other. Because of this feature, the .NET Framework supports development in multiple programming languages. This is discussed in more detail in Microsoft .NET Languages.
* Base Class Library - The Base Class Library (BCL), part of the Framework Class Library (FCL), is a library of types available to all languages using the .NET Framework. The BCL provides classes which encapsulate a number of common functions, including file reading and writing, graphic rendering, database interaction and XML document manipulation.
* Simplified Deployment - Installation of computer software must be carefully managed to ensure that it does not interfere with previously installed software, and that it conforms to increasingly stringent security requirements. The .NET framework includes design features and tools that help address these requirements.
* Security - .NET allows for code to be run with different trust levels without the use of a separate sandbox.
A design goal of the .NET Framework was to support platform independence[citation needed]. That is, a program written to use the framework should run without change on any type of computer for which the framework is implemented. However, Microsoft has only implemented the full .NET framework on the Windows operating system. Microsoft and others have implemented portions of the framework on non-Windows systems, but to date these implementations are neither complete nor widely used, so full cross-platform support has not been achieved.
[edit] .NET Framework architecture
Visual overview of the Common Language Infrastructure (CLI)
Visual overview of the Common Language Infrastructure (CLI)
[edit] Common Language Infrastructure (CLI)
Main article: Common Language Infrastructure
The important component of the .NET Framework lies within the Common Language Infrastructure, or CLI. The purpose of the CLI is to provide a language-agnostic platform for application development and execution, including, but not limited to, components for exception handling, garbage collection, security, and interoperability. Microsoft's implementation of the CLI is called the Common Language Runtime, or CLR. The CLR is composed of four primary parts:
* Common Type System (CTS)
* Common Language Specification (CLS)
* Just-In-Time Compiler (JIT)
* Virtual Execution System (VES)
[edit] Assemblies
Main article: .NET assembly
The intermediate CIL code is housed in .NET assemblies, which for the Windows implementation means a Portable Executable (PE) file (EXE or DLL). Assemblies are the .NET unit of deployment, versioning and security. The assembly consists of one or more files, but one of these must contain the manifest, which has the metadata for the assembly. The complete name of an assembly contains its simple text name, version number, culture and public key token; it must contain the name, but the others are optional. The public key token is generated when the assembly is created, and is a value that uniquely represents the name and contents of all the assembly files, and a private key known only to the creator of the assembly. Two assemblies with the same public key token are guaranteed to be identical. If an assembly is tampered with (for example, by hackers), the public key can be used to detect the tampering.
[edit] Metadata
Main article: .NET metadata
All CIL is Self-Describing through .NET metadata. The CLR checks on metadata to ensure that the correct method is called. Metadata is usually generated by language compilers but developers can create their own metadata through custom attributes. Metadata also contain all the information about assembly.
--> The Base Class Library , sometimes incorrectly referred to as the Framework Class Library (FCL) (which is a superset including the Microsoft.* namespaces), is a library of classes available to all languages using the .NET Framework. The BCL provides classes which encapsulate a number of common functions such as file reading and writing, graphic rendering, database interaction, XML document manipulation, and so forth. The BCL is much larger than other libraries, but has much more functionality in one package.
[edit] Security
.NET has its own security mechanism, with two general features: Code Access Security (CAS), and validation and verification. Code Access Security is based on evidence that is associated with a specific assembly. Typically the evidence is the source of the assembly (whether it is installed on the local machine, or has been downloaded from the intranet or Internet). Code Access Security uses evidence to determine the permissions granted to the code. Other code can demand that calling code is granted a specified permission. The demand causes the CLR to perform a call stack walk: every assembly of each method in the call stack is checked for the required permission and if any assembly is not granted the permission then a security exception is thrown.
When an assembly is loaded the CLR performs various tests. Two such tests are validation and verification. During validation the CLR checks that the assembly contains valid metadata and CIL, and it checks that the internal tables are correct. Verification is not so exact. The verification mechanism checks to see if the code does anything that is 'unsafe'. The algorithm used is quite conservative and hence sometimes code that is 'safe' is not verified. Unsafe code will only be executed if the assembly has the 'skip verification' permission, which generally means code that is installed on the local machine.
[edit] Standardization and licensing
In August 2000, Microsoft, Hewlett-Packard, and Intel worked to standardize CLI and the C# programming language. By December 2001, both were ratified ECMA standards (ECMA 335 and ECMA 334). ISO followed in April 2003 (ISO/IEC 23271 and ISO/IEC 23270).
While Microsoft and their partners hold patents for CLI and C#, ECMA and ISO require that all patents essential to implementation be made available under "reasonable and non-discriminatory (RAND) terms." In addition to meeting these terms, the companies have agreed to make the patents available royalty-free.
However, this does not apply for the part of the .NET Framework which is not covered by the ECMA/ISO standard, which includes Windows Forms, ADO.NET, and ASP.NET. Patents that Microsoft holds in these areas may deter non-Microsoft implementations of the full framework.
[edit] Versions
Microsoft started development on the .NET Framework in the late 90s originally under the name of Next Generation Windows Services (NGWS). By late 2000 the first beta versions of .NET 1.0 were being released.
Version Name Version Number Release Date
1.0 Beta 1 1.0.????.0 2000-11
1.0 Beta 2 1.0.2914.0 2001-06-20
1.0 RTM 1.0.3705.0 2002-01-05
1.0 SP1 1.0.3705.209 2002-03-19
1.0 SP2 1.0.3705.288 2002-08-07
1.0 SP3 1.0.3705.6018 2004-08-31
1.1 RTM 1.1.4322.573 2003-04-01
1.1 SP1 1.1.4322.2032 2004-08-30
1.1 SP1 (Windows Server 2003 Version) 1.1.4322.2300 2005-03-30
2.0 RTM 2.0.50727.42 2005-11-07
3.0 RTM 3.0.4506.30 2006-11-06
3.5 Beta 2 3.5.20706.1 2007-07-26
[edit] .NET Framework 1.0
This is the first release of the .NET Framework. Released on February 13, 2002. It is available on its own as a redistributable package or in a software development kit. It is also part of the first release of Microsoft Visual Studio .NET (also known as Visual Studio .NET 2002).
[edit] .NET Framework 1.1
This is the first major .NET Framework upgrade. It is available on its own as a redistributable package or in a software development kit, and was published April 3, 2003. It is also part of the second release of Microsoft Visual Studio .NET (released as Visual Studio .NET 2003). This is the first version of the .NET Framework to be included as part of the Windows operating system, shipping with Windows Server 2003.
[edit] Changes since 1.0
* Built-in support for mobile ASP.NET controls. Previously available as an add-on for .NET Framework, now part of the framework.
* Security changes - enable Windows Forms assemblies to execute in a semi-trusted manner from the Internet, and enable Code Access Security in ASP.NET applications.
* Built-in support for ODBC and Oracle databases. Previously available as an add-on for .NET Framework 1.0, now part of the framework.
* .NET Compact Framework - a version of the .NET Framework for small devices.
* Internet Protocol version 6 (IPv6) support.
* Numerous API changes.
[edit] .NET Framework 2.0
Released with Visual Studio .NET 2005, Microsoft SQL Server 2005 and BizTalk 2006.
* The 2.0 Redistributable Package can be downloaded for free from Microsoft, and was published on 2006-01-22.
* The 2.0 Software Development Kit (SDK) can be downloaded for free from Microsoft.
* It is included as part of Visual Studio 2005 and Microsoft SQL Server 2005.
* Version 2.0 is the last version with support for Windows 2000.
* It shipped with Windows Server 2003 R2 (not installed by default).
[edit] Changes since 1.1
* Numerous API changes.
* A new hosting API for native applications wishing to host an instance of the .NET runtime. The new API gives a fine grain control on the behavior of the runtime with regards to multithreading, memory allocation, assembly loading and more (detailed reference). It was initially developed to efficiently host the runtime in Microsoft SQL Server, which implements its own scheduler and memory manager.
* Full 64-bit support for both the x64 and the IA64 hardware platforms.
* Language support for Generics built directly into the .NET CLR.
* Many additional and improved ASP.NET web controls.
* New data controls with declarative data binding.
* New personalization features for ASP.NET, such as support for themes, skins and webparts.
* .NET Micro Framework - a version of the .NET Framework related to the Smart Personal Objects Technology initiative more....
[edit] .NET Framework 3.0
Architecture of the .NET Framework 3.0
Architecture of the .NET Framework 3.0
.NET Framework 3.0, formerly called WinFX,[1] includes a new set of managed code APIs that are an integral part of Windows Vista and Windows Server 2008 operating systems. It is also available for Windows XP SP2 and Windows Server 2003 as a download. There are no major architectural changes included with this release; .NET Framework 3.0 includes version 2.0 of the Common Language Runtime.[2]
.NET Framework 3.0 consists of four major new components:
* Windows Presentation Foundation (WPF), formerly code-named Avalon; a new user interface subsystem and API based on XML and vector graphics, which uses 3D computer graphics hardware and Direct3D technologies. See WPF SDK for developer articles and documentation on WPF.
* Windows Communication Foundation (WCF), formerly code-named Indigo; a service-oriented messaging system which allows programs to interoperate locally or remotely similar to web services.
* Windows Workflow Foundation (WWF) allows for building of task automation and integrated transactions using workflows.
* Windows CardSpace (WCS), formerly code-named InfoCard; a software component which securely stores a person's digital identities and provides a unified interface for choosing the identity for a particular transaction, such as logging in to a website.
[edit] .NET Framework 3.5
This article or section contains information about computer software currently in development.
The content may change as the software development progresses.
* This version of the framework uses version 2.0 of the CLR (the same model as the use of CLR 2.0 in .NET Framework 3.0). However changes are applied to the installed CLR 2.0.
* Full support for .NET Framework 3.5 project types, as well as targeting .NET Framework 3.5 in builds, will be included in Visual Studio 2008.
Changes
* New language features in C# 3.0 and VB.NET 9.0 compiler
* C# 3.0 adds support for expression trees and lambda methods
* Extension methods
* Anonymous types with static type inference
* Language Integrated Query (LINQ) along with its various providers
o LINQ to Objects
o LINQ to XML
o LINQ to SQL
* Paging support for ADO.NET
* ADO.NET synchronization API to synchronize local caches and server side datastores
* Asynchronous network I/O API[3]
* Peer-to-peer networking stack, including a managed PNRP resolver[4]
* Managed wrappers for WMI and Active Directory APIs[5]
* Enhancements to the WCF and WF runtimes that let WCF work with POX and JSON data, as well as expose WF workflows as WCF services.[6]
* Support for HTTP pipelining and syndication feeds.[6]
