. NET Framework and framework class library

. NET Framework has two main components: Public Language Runtime Library and. NET Framework class library. The public Language Runtime Library is the basis of the. NET Framework. You can regard the Runtime Library as a proxy for managing code during execution. It provides core services such as memory management, thread management, and remote processing, strict type security and other forms of code accuracy that can improve security and reliability are also enforced. In fact, the concept of code management is the basic principle of the Runtime Library. Code with the Runtime Library as the target is called managed code, and code with the Runtime Library as the target is called unmanaged code .. Another major component of the. NET Framework is the class library, which is a comprehensive collection of reusable object-oriented types. You can use it to develop a variety of applications, these applications include traditional command line or graphical user interface (GUI) applications, and also include ASP-based. NET provides the latest innovative applications (such as web forms and XML WebServices ).

. The. NET framework can be carried by unmanaged components that Load Common Language Runtime libraries to their processes and start the execution of managed code, in this way, you can create a software environment that can take advantage of both managed and unmanaged functions .. NET framework not only provides several runtime database hosts, but also supports the development of third-party runtime database hosts.

For example, ASP. NET hosts the runtime to provide a Scalable Server Environment for hosted code. ASP. NET directly uses the Runtime Library to enable ASP. NET applications and XML Web Services (this topic will discuss the two later ).

Internet Explorer is an example of an unmanaged application that hosts the Runtime Library (in the form of mime-type extensions. Using internetexplorer to host the Runtime Library enables you to embed an import pipe component or a Windows Form Control in HTML documents. Running libraries in this way makes it possible to host Mobile Code (similar to Microsoft ActiveX controls), but it requires significant improvements (such as incomplete trusted execution and independent file storage ), this improvement can only be provided by hosted code.

The following illustration shows the relationship between the Common Language Runtime Library and the class library and the application and the entire system. The illustration also shows how managed code runs in a larger structure.

. NET Framework Environment

 

1. Language
Visual Studio. NET contains four languages: Visual Basic, Visual C ++, Visual C #, and JScript. However, the modularization of the. NET framework allows other languages created by a third party to be integrated into Visual Studio. NET. There are more than 20 languages, including Perl, component Pascal, smallscript, and smalltalk.

2. Public language specifications
This specification is the basis for implementing all languages of the. NET Framework and defines the standards of public-type systems and the functions required by all languages. This is the basis for third-party language and framework integration.

3. Windows Forms
All languages share the common Windows Forms engine. The Form Designer is consistent in all languages, so all languages can access the same inherent controls that provide the same attributes and methods. Even if you use different languages for development, the interface has the same appearance.

4. ASP. NET
This is the basic technology for web forms and XML Web Services. Web forms are used for front-end web development, while XML Web Services provide functions through Intranet or Internet.

5. Data Management
Ado. Net replaces ADO as the data processing mechanism in the. NET Framework. It is a highly scalable technology that uses XML for data transmission.

6. Base Class Library
These classes provide consistent and easy-to-use methods for accessing various information (such as system information and user information), which was previously accessed, special components or APIs must be used.

7. Common Language Runtime (CLR)
CLR provides a hosting execution environment and compilation service for the compiler. The CLR compiler compiles the source code into an intermediate language (IL) and then executes il in real-time (JIT) mode. All source languages share Clr and are compiled into the same Il.

8.. NET Framework Structure

 

9.. NET Framework class

10. the. NET Framework Class Library provides the following namespaces:

Microsoft. CSHARP: Contains classes that support C # compilation and code generation.

Microsoft. JScript: Contains JScript runtime libraries and classes that support JScript Language compilation and code generation.

Microsoft. VisualBasic: contains the Visual Basic. Net Runtime Library. This Runtime library is used with the Visual Basic. NET language. This namespace also contains classes that support compiling and code generation using Visual Basic. net.

Microsoft. VSA: contains interfaces that allow you to integrate. NET Framework Script Engine scripts into applications and compile and execute code at runtime.

Microsoft. Win32: provides two types of classes: the class for processing events caused by the operating system and the class for operating the system registry.

System: contains the basic class and base class used to define common values and reference data types, events and event handlers, interfaces, properties, and handle exceptions.

Other types provide services that support data type conversion, method parameter operations, mathematical computing, remote and local program calls, application environment management, and supervision over hosted and unmanaged applications.

System. codedom: Contains classes that can be used to represent elements and structures of source code documents.

System. codedom. compiler: Contains classes that can be used to manage the generation and compilation of source code written in supported programming languages based on the structure of the Code Document Object Model (codedom) source code model.

System. Collections: contains interfaces and classes that define various object sets (such as lists, queues, bit arrays, hash tables, and dictionaries.

System. Collections. Specialized: contains a dedicated set of strong types, such as a chain table dictionary, a bit vector, and a set containing only strings.

System. componentmodel: provides classes used to implement runtime and design-time behavior of components and controls. This namespace includes the basic classes and interfaces used for Attribute and type converter implementation, data source binding, and component authorization.

System. componentmodel. Design: allows developers to generate Custom User interface controls and include them in the design environment for use with supplier controls.

System. componentmodel. Design. serialization: provides support for component serialization by the designer. Classes in this namespace can be used to provide custom serialization programs, manage specific types of serialization, manage designer loading and designer serialization, and optimize designer reload.

System. Configuration: provides classes and interfaces that allow you to programmatically access. NET Framework configuration settings and handle errors in the configuration file (. config file.

System. configuration. assemblies: contains the class used to configure the assembly.

System. configuration. Install: provides a class that allows you to write custom installation programs for your components. The installer class is the base class of all custom installers in the. NET Framework.

System. Data: It is basically composed of classes that constitute the ADO. net structure. The ADO. net structure allows you to generate components that can be used to effectively manage data in multiple data sources. In the disconnected Scheme (such as the Internet), ADO. NET provides some tools to request, update, and coordinate data in a multi-tier system. The ADO. net structure can also be implemented in client applications (such as Windows Forms) or HTML pages created by ASP. NET.

System. Data. Common: Contains classes shared by. NET data providers .. . NET data provider describes a set of classes used to access data sources (such as databases) in a hosted space.

System. Data. oledb: encapsulate the ole db. NET data provider .. . NET data provider describes a set of classes used to access data sources (such as databases) in a hosted space.

System. Data. sqlclient: encapsulate the SQL server. NET data provider .. . NET data provider describes a set of classes used to access data sources (such as databases) in a hosted space.

System. Data. sqltypes: provides a class for the local data type in SQL Server. These classes provide a safer and faster alternative to other data types. Using classes in this namespace helps prevent type conversion errors that may result in loss of precision.

System. Diagnostics: provides classes that allow interaction with system processes, event logs, and performance counters. This namespace also provides classes that enable you to debug applications and trace code execution. For more information, see trace and debug classes.

System. Diagnostics. symbolstore: provides a class that enables you to read and write debugging symbolic information (such as the source row mapped by Microsoft intermediate language (msil. The. NET Framework-oriented compiler can store the debugging symbol information to the programmer's database (PDB) file. The debugger and code analyzer tool can read debugging symbol information at runtime.

System. directoryservices: provides methods to easily access Active Directory from managed code.

System. Drawing: provides access to the GDI + basic graphics function.

The system. Drawing. drawing2d, system. Drawing. imaging, and system. Drawing. Text Namespaces provide more advanced functions.

System. Drawing. Design: contains the user interface (UI) logic and drawn class during the extension design. This design-time feature can be further extended to create a custom toolbox item, type-specific value Editor (editable and graphically representing supported types of values) or type converter (values can be converted between specific types ).

System. Drawing. drawing2d: Provides advanced 2D and vector graphics Functions. This namespace includes gradient paint brushes, matrix classes (used to define geometric conversions), and graphicspath classes.

System. Drawing. Imaging: Provides advanced GDI + image processing functions. The basic graphics function is provided by the system. Drawing namespace.

System. Drawing. Printing: Provides printing-related services.

System. Drawing. Text: Provides advanced GDI + layout functions. The basic graphics function is provided by the system. Drawing namespace. Classes in this namespace allow you to create and use a font set.

System. enterpriseservices: provides an important infrastructure for enterprise-level applications. COM + provides a service structure for the component programming model deployed in an enterprise-level environment. This namespace provides access to the COM + service for. NET Framework objects, so that. NET Framework objects are more suitable for enterprise-level applications.

System. isiseservices. compensatingresourcemanager: provides classes that enable you to use compensation Resource Manager (CRM) in managed code. CRM is a service provided by COM +. It allows you to include non-transactional objects in Microsoft Distributed Transaction Processing Coordinator (DTC) transactions. While CRM does not provide full resource manager functionality, they provide transactional atomicity (full or full Act) and durability by restoring logs.

System. Globalization: A class that defines information about a region. The information includes the language, country, calendar in use, date format, currency, number, and string sorting order.

System. IO: contains the types that allow synchronous and asynchronous reading and writing of data streams and files.

System. Io. isolatedstorage: contains the types that allow the creation and use of independent storage zones. By using these buckets, you can read and write data that cannot be accessed by code with a small degree of trust, and prevent the disclosure of sensitive information stored elsewhere in the file system. Data is stored in a data compartment independent of the current user and the Assembly where the code is located.

System. Management: provides access to a rich set of management information and management events about systems, devices, and applications that comply with the Windows Management specifications (Wmi) infrastructure.

System. Management. instrumentation: Provides the classes necessary to standardize application management and expose management information and events to potential users through WMI. In this way, users such as Microsoft Application Center or Microsoft Operations Manager can easily manage your applications, while administrator scripts or other applications (hosting applications and unmanaged applications) you can also monitor and configure your applications.

System. messaging: provides a class that enables you to connect, monitor, and manage message queues on the network and send, receive, or view messages.

System. Net: Provides simple programming interfaces for various protocols used in the current network. The webrequest and webresponse classes form the foundation of the so-called pluggable protocol. This protocol is a network service implementation that allows you to develop applications that use Internet resources, you do not have to consider the details of each protocol.

System. net. sockets: provides Windows Socket (Winsock) interface hosting for developers who require strict network access control.

System. Reflection: Contains classes and interfaces that provide hosted views for loaded types, methods, and fields, and can dynamically create and call types.

System. reflection. emit: class that allows the compiler or tool to issue metadata and Microsoft intermediate language (msil) and generate PE files on disk (optional. The main clients of these classes are the script engine and compiler.

System. Resources: provides classes and interfaces that allow developers to create, store, and manage specific regional resources used in applications.

System. runtime. compilerservices: provides functions for Compiler writers that use hosted code to specify attributes in the metadata that affects the runtime behavior of the common language runtime. The classes in this namespace are only used by the compiler writer.

System. runtime. interopservices: provides a set of classes used to access COM objects and local APIs from. net. The types in this namespace are divided into the following functional areas: properties, exceptions, managed definitions of COM types, packaging, Type converters, and Marsha classes.

System. runtime. interopservices. expando: contains the iexpando interface, which allows you to modify objects by adding or removing object members.

System. runtime. remoting: provides classes and interfaces that allow developers to create and configure distributed applications.

System. runtime. remoting. Activation: provides classes and objects that support remote object activation on servers and clients.

System. runtime. remoting. channels: Contains classes that support and process channels and Channel Receivers. These channels and Channel Receivers are used as transmission media when clients call methods for remote objects.

System. runtime. remoting. channels. http: contains a channel for transmitting messages and objects between HTTP and remote locations. By default, HTTP channels encode objects and method calls in soap format for transmission, but other encoding and decoding formatting program receivers can also be specified in Channel Configuration attributes.

System. runtime. remoting. channels. TCP: contains a channel for transmitting messages and objects between the TCP protocol and remote locations. By default, the TCP channel encodes the object and method call in binary format for transmission, but other encoding and decoding formatting program receivers can also be specified in the Channel Configuration attributes.

System. runtime. remoting. contexts: contains the object that defines the context where all objects reside. Context is an ordered attribute sequence used to define the environment in which objects reside. Context is created during object activation. These objects are configured to require certain automatic services, such as synchronization, transactions, real-time (JIT) activation, and security. Multiple objects can be stored in one context.

System. runtime. remoting. lifetime: contains the class for managing the lifetime of remote objects. Traditionally, the distributed garbage collection function uses reference counting and Ping to control the object's survival. This mechanism works normally when each service has only a few clients, but it cannot work normally when each service has thousands of clients. The remote processing Lifetime Service Associates each service with a lease. When the lease expires, the service is deleted. The lifetime service can serve as a traditional distributed garbage collector, and can be well adjusted when the number of clients for each service increases.

System. runtime. remoting. messaging: Contains classes used to create and remotely process messages. The basic structure of remote processing uses messages to communicate with remote objects. Messages are used to transmit remote method calls, activate remote objects, and exchange information. A message object carries a group of naming attributes, including operation identifiers, representative information, and parameters.

System. runtime. remoting. Metadata: Contains classes and attributes that can be used to customize soap generation and processing for objects and fields. The classes in this namespace can be used to indicate soapaction, type output, XML element name, and XML namespace URI method.

System. runtime. remoting. Metadata. w3cxsd2001: contains the XML schema definition (XSD) defined by the WWW Federation (W3C) in 2001 ). The XML Schema Part2: Data Types (XML architecture Part 2: Data Types) specification in W3C determines the formats and behaviors of various data types. This namespace contains packages that comply with W3C specifications for data types. All Date and Time types comply with ISO standards.

System. runtime. remoting. metadataservices: Contains classes that are used by the soapsuds.exe command line tool and user code to convert each other between metadata and the XML schema of the remote processing infrastructure.

System. runtime. remoting. Proxies: Contains classes that control and provide Proxy functions. A proxy is a local object used as a remote object image. The proxy allows the client to access objects across remote processing boundaries.

System. runtime. remoting. Services: A service class that provides functions for the. NET Framework.

System. runtime. serialization: Contains classes that can be used to serialize and deserialize objects. Serialization refers to the process of converting an object or object graph to a linear byte sequence for storage or transmission to another location. Deserialization is the process of accepting stored information and re-creating an object with such information.

System. runtime. serialization. formatters: provides general enumeration, interfaces, and classes used by serialized formatting programs.

System. runtime. serialization. formatters. Binary: contains the binaryformatter class that can be used to serialize and deserialize objects in binary format.

System. runtime. serialization. formatters. Soap: contains the soapformatter class that can be used to serialize and deserialize objects in the soap format.

System. Security: Provides the infrastructure of the security system of the Runtime Library in the public language, including the base class of permissions.

System. Security. Cryptography: provides encryption services, including secure data encoding and decoding, and many other operations, such as hash processing, random number generation, and message authentication.

System. Security. cryptography. x509certificates: A Public Language Runtime implementation that contains the Authenticode X.509 V.3 certificate. This certificate uniquely identifies the Private Key signature of the certificate holder.

System. Security. cryptography. xml: contains the XML model exclusively used in the. NET Framework security system. This XML model should not be used for general purposes. This model allows you to digitally sign an XML object.

System. Security. Permissions: defines the class for controlling operations and resource access based on policies.

Lsystem. Security. Policy: Contains code groups, member conditions, and evidence. These three types of classes are used to create rules applied by the security policy system of the public Language Runtime Library. The evidence class is the input of the security policy, and the member condition is the switch. The two jointly create the policy statement and determine the authorized permission set. Policy level and code group are the structure of policy level. Code groups are rules encapsulated and arranged hierarchically at the policy level.

System. Security. Principal: defines the user object that represents the security context of the Code to run.

System. serviceprocess: provides a class that enables you to implement, install, and control Windows service applications. The service is an executable file that does not require long-term running of the user interface. The service implementation process includes: Inheriting from the servicebase class, defining specific actions that are processed when a command is passed in to start, stop, pause, and continue, and define the user-defined behaviors and operations when the system is shut down.

System. text: Contains classes that represent ASCII, Unicode, UTF-7, and UTF-8 character encoding; abstract base classes used to convert between character blocks and byte blocks; and you can operate and format the helper class of the string object without creating an intermediate instance of the string.

System. Text. regularexpressions: class that provides access to the. NET Framework Regular Expression Engine. This namespace provides the regular expression function that can be used in any platform or language that runs on the Microsoft. NET Framework.

System. Threading: provides classes and interfaces that support multi-threaded programming. This namespace includes the threadpool class for managing thread groups, the Timer class that allows the delegate to be called after a specified period of time, and the mutex class for synchronizing mutually exclusive threads. This namespace also provides classes for thread arrangement, waiting for notification, and deadlock resolution.

System. Timers: Provides timer components that allow events to be triggered at specified intervals.

System. Web: provides classes and interfaces that support Browser/Server Communication. This namespace includes the httpresponse class that provides a large amount of information about the current HTTP request and the httpresponse class that manages the output from http to client, and the httpserverutility object that provides access to server utilities and processes. System. Web also includes classes for Cookie operations, file transmission, exception information, and output Cache control.

System. Web. Caching: provides classes for caching common resources on servers. These resources include ASP. NET pages, Web Services, and user controls. In addition, cache dictionaries allow you to store frequently-used resources, such as hash tables and other data structures.

System. Web. Configuration: contains the class used to set ASP. NET configurations.

System. Web. Hosting: provides the ability to host ASP. NET applications from outside Microsoft Internet informationserver (IIS.

System. Web. mail: Contains classes that enable you to construct and send messages using the cdosys message component. Mail messages are sent through the built-in SMTP mail service in Microsoft Windows 2000 or any SMTP server. Classes in this namespace can be used in ASP. NET or any hosted application.

System. Web. Security: Contains classes used to implement ASP. Net Security in Web server applications.

System. Web. services: these classes enable you to generate and use web services. Web services are programmable entities that reside on web servers and are exposed through standard Internet protocols.

System. Web. Services. Configuration: it consists of several classes. These classes are configured to run XML Web Services created using ASP. NET.

System. Web. Services. Description: consists of classes that allow you to publicly describe XML Web Services using the Web Service Description Language (WSDL. Each class in this namespace corresponds to a specific element in the WSDL specification, and the class hierarchy corresponds to the XML structure of a valid WSDL document.

System. Web. Services. Discovery: consists of classes that allow the XML Web Services Client to locate the xmlweb services available on the Web server through a process called "XML Web Services Discovery.

System. web. services. protocols: consists of several classes, which are defined in the XML WebServices client and ASP.. net.

System. Web. sessionstate: provides classes and interfaces for storing data of a single client specific to a web application on the server. Session status data is used to provide the client with the appearance of a persistent connection to the application. The status information can be stored in the local process memory, or, for network farm configuration, ASP. NET status service or SQL Server database can be used to store the status information outside the process.

System. Web. UI: provides classes and interfaces that allow you to create controls and pages that appear in Web applications in the form of user interfaces on Web pages. This namespace includes the control class, which provides a set of common functions for all controls (whether HTML control, web control or user control. It also includes the page control, which is automatically generated whenever a request is sent to a page in a web application. In addition, some classes are provided, which provide the Web forms Server Control Data Binding function, and the ability to save the view status of a given control or page, and analysis functions applicable to both programmable controls and text controls.

System. Web. UI. Design: Contains classes that can be used to extend web forms.

System. Web. UI. Design. webcontrols: Contains classes that can be used to extend the Web server control design.

System. Web. UI. htmlcontrols: provides a class that allows you to create HTML server controls on Web pages. The HTML server controls run on the server and are directly mapped to standard HTML tags supported by all browsers. This allows you to programmatically control HTML elements on Web pages.

System. Web. UI. webcontrols: contains a class that allows you to create Web server controls on a web page. Web controls run on the server and include Form Controls (such as buttons and text boxes) and special-purpose controls (such as calendar ). This allows you to programmatically control these elements on Web pages. Web controls are more abstract than HTML controls. Their object models do not necessarily reflect the HTML syntax.

System. Windows. Forms: Contains classes used to create windows-based applications that take full advantage of the rich user interface functions in the Microsoft Windows operating system.

System. Windows. Forms. Design: Contains classes that can be used to extend the design of Windows Forms.

System. xml: supports standard-based XML processing.

System. xml. Schema: provides standard-based XML architecture (XSD) support.

System. xml. serialization: contains a class used to serialize an object to a document or stream in XML format.

System. xml. XPath: contains the XPath analyzer and computing engine. It supports the W3C XML Path Language (XPath) Version 1.0 recommendation (www.w3.org/tr/xpath ).

System. xml. XSL:

Supports extensible style sheet conversion (XSLT) conversion. It supports W3C XSL conversion (XSLT) Version 1.0 recommendations (www.w3.org/tr/xslt ). You can filter the reference documents of the class libraries by language to view some languages (managed extensions of Visual Basic, C #, C ++ or JScript) you can also view the syntax, instructions, and examples of all these four languages. To filter by language, click the filter icon at the top of any reference page and select a language or show all ".