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The. NET Framework class library is a library composed of classes, interfaces, and value types in the Microsoft. NET Framework SDK. This library provides access to system functions and serves as the basis for creating. NET Framework applications, components, and controls.
The. NET Framework Class Library provides the following namespaces:
Microsoft. CSHARP Contains classes that support C # compilation and code generation.
Microsoft. JScript Contains classes that support JScript Language compilation and code generation.
Microsoft. VisualBasic Contains classes that support Visual Basic. NET language compilation and code generation.
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 classes and basic classes used to define common values and reference data types, events and event handlers, interfaces, properties, and handle exceptions.
Other types provide services that support the following operations: 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. These elements can be used to create the structure of the source code document. By using the functions provided by the system. codedom. compiler namespace, You can output source code documents as source code written in Supported languages.
System. codedom. compiler contains types used to manage source code generation and compilation in supported programming languages. Each code generator can be based on the structure of the source code model of the "Code Document Object Model" (codedom. the elements provided by The codedom namespace). The source code is generated using a specific programming language.
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 that only contains 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 Contains classes that can be used by developers to generate component behavior during custom design and to configure the user interface of components during design. The design environment provides a system that allows developers to arrange components and configure their attributes.
System. componentmodel. Design. serialization provides support for customizing and controlling serialization types during design.
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 allows you to write a class for a custom installer for your components. The installer class is the base class of all custom installers in. NET Framework.
System. Data 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 from 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 Framework data providers .. NET framework data provider describes a set of classes used to access data sources (such as databases) in a hosted space.
System. Data. ODBC encapsulates the ODBC. NET Framework data provider .. NET framework data provider describes a set of classes used to access data sources (such as databases) in a hosted space. Use
The odbcdataadapter class can be used to populate the dataset residing in the memory and query and update data sources.
For more information about how to use this namespace, see odbcdatareader, odbccommand, and odbcconnection.
Note: This namespace is only supported in. NET Framework 1.1.
System. Data. oledb encapsulates the ole db. NET Framework data provider. The ole db. NET Framework data provider describes a collection of classes used to access the ole db data source in a hosted space.
System. Data. oracleclient encapsulates the Oracle. NET Framework data provider. The Oracle. NET Framework data provider describes a collection of classes used to access Oracle data sources in a hosted space.
Note: This namespace is only supported in. NET Framework 1.1.
System. Data. sqlclient encapsulates the SQL server. NET Framework data provider. The SQL Server. NET Framework data provider describes a set of classes used to access the SQL Server database in a hosted space.
System. Data. sqlserverce: A class set used to access the database in SQL Server ce from a Windows CE-based device in a hosted environment. This namespace allows you to create an SQL Server ce database on one device and establish a connection with an SQL Server database on another device or remote server.
Note: This namespace is only supported in. NET Framework 1.1.
System. Data. sqltypes provides classes 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. Because other data types and sqltypes are converted to each other in the background, explicit creation and use of objects in this namespace also produce fast code.
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.
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 a way to easily access Active Directory from managed code. This namespace contains two component classes: directoryentry and directorysearcher. These two classes use the Active Directory Service Interface (ADSI) technology. ADSI is a set of interfaces provided by Microsoft and a tool that can flexibly process various network providers. ADSI allows administrators to easily search for and manage network resources, regardless of the network size.
System. Drawing provides access to the basic graphics Functions of GDI +.
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 drawing class for the extension design. This design-time function can be further extended to create the following objects: Custom toolbox items, value editors of specific types, and Type converters, the type-specific value editor is used to edit and graphically represent supported types of values. The type converter is used to convert values between specific types. This namespace provides a basic framework for user interface extension during development and design.
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. Generally, you can create an instance of the printdocument class, set attributes that describe the printed content, and call the print method to actually print the document.
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. enterpriseservices. Internal provides the infrastructure support for the COM + service. The classes and interfaces in this namespace are used to support the transfer of system. isiseservices from an unmanaged COM + class.
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. These classes are useful for writing global (international) applications.
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 Instrumentation (Wmi) infrastructure.
System. Management. instrumentation provides the classes required 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 allows 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 Contains classes that allow compilers or tools to issue metadata and Microsoft intermediate language (msil) and generate PE files on disks (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 various members that support the com InterOP and platform call services. If you are not familiar with these services, see interacting with non-hosted code.
System. runtime. interopservices. custom‑alers supports the. NET infrastructure and is not directly used in code.
System. runtime. interopservices. expando contains the iexpando interface, which allows you to modify objects by adding or removing objects.
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, which are used as transmission media when clients call methods on 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 objects that define 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 classes 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 remote processing infrastructure 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 World Wide Web 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 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 contains services that provide functions for. 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 the serialized formatter.
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 basic structure of the. NET Framework security system, 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 implements the Common Language Runtime library containing the Authenticode X.509 V.3 certificate. This certificate uniquely identifies the Private Key signature of the certificate holder.
System. Security. cryptography. xml Contains classes that support creating and verifying XML digital signatures. The classes in this namespace comply with the W3C recommendation "XML-signature syntax and processing" (XML Signature syntax and processing). For details, see http://www.w3.org/tr/xmldsig-core /.
System. Security. Permissions defines the classes used to control operations and access resources based on policies.
System. Security. Policy contains the code group, member conditions, and evidence. These three types of classes are used to create rules applied by the. NET Framework security policy system. 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 subject object that represents the security context of the Code to run.
System. serviceprocess provides classes that enable you to implement, install, and control Windows service applications. A service is an executable file that runs for a long time without a 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 Contains classes that provide access to the. NET Framework Regular Expression Engine. The Regular Expression feature provided by this namespace can be used on any platform or language running in Microsoft. NET Framework.
System. Threading provides classes and interfaces that support multi-threaded programming. In addition to the classes used to synchronize thread activity and data access (mutex, monitor, interlocked, autoresetevent, and so on, this namespace also includes a threadpool class (which enables you to use the thread pool provided by the system) and a Timer class (which executes the callback Method for threads in the thread pool ).
System. Timers provides the timer component that allows the event to be triggered at a specified interval.
System. Web provides classes and interfaces that support Browser/Server Communication. This namespace includes the httprequest class (which provides a large amount of information about the current HTTP request) and the httpresponse class (which manages the output from http to client) and httpserverutility object (which provides access to server-side 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 data on servers. This includes a cache class, which is a dictionary in which you can store any data objects, such as hash tables and datasets. It also provides invalid functions for these objects and provides you with methods to add and remove these objects. You can also add objects dependent on other files or cache items, and execute a callback when an object is removed from the cache to notify your application.
System. Web. Configuration Contains classes used to set ASP. NET configurations.
System. Web. Hosting provides the ability to host ASP. NET applications from an external hosted application of Microsoft Internet Information Service (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. Mobile contains the core functions required to generate ASP. NET mobile Web applications, including identity authentication and error handling.
System. Web. Security contains classes used to implement ASP. Net Security in Web server applications.
System. Web. Services allows you to use ASP. NET and XML Web Services clients to create XML Web Services classes. XML Web Services are some applications that provide the ability to exchange messages in a loosely coupled environment using standard protocols (such as HTTP, XML, XSD, soap, and WSDL. XML Web Services can generate modular applications within and between companies in a heterogeneous environment, enabling them to interact with various implementations, platforms, and devices. Each part of the soap-based XML message of these applications can be strictly defined (structured and typed) or loosely defined (using any XML ). These messages can develop over time without disrupting the Protocol. This capability is fundamental to the flexibility and reliability of XML Web Services as Web construction blocks in the future.
System. Web. Services. configuration 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 several classes that allow the XML Web Services Client to locate available XML Web Services on the Web server through a process called "XML Web Services Discovery.
System. web. services. protocols is composed of several classes, which are defined in the XML Web Services Client and ASP.. net.
System. Web. sessionstate provides classes and interfaces for storing data of a single client specific to Web applications 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 allows you to create controls and page classes and interfaces 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 the design of web forms.
System. Web. UI. Design. webcontrols Contains classes that can be used to extend the Web server control design.
System. Web. UI. htmlcontrols allows you to create a class set of HTML server controls on the web form page. The HTML server controls run on the server and are directly mapped to standard HTML tags supported by most browsers. This allows you to programmatically control HTML elements on web forms pages.
System. Web. UI. mobilecontrols contains a set of ASP. NET Server controls that intelligently present your applications to different mobile devices.
System. Web. UI. mobilecontrols. adapters contains the core device adapter classes that are used by ASP. NET mobile controls to customize devices and support extended devices.
System. Web. UI. webcontrols Contains classes that allow you to create Web server controls on Web pages. The Web server control runs on the server and includes buttons, text boxes, and other form controls. They also include special controls similar to calendars. Since Web server controls run on servers, these elements can be controlled programmatically. Web server controls are more abstract than HTML server controls. Their object models do not necessarily reflect the HTML syntax.
System. Windows. Forms Contains classes used to create windows-based applications. These applications can take full advantage of the rich user interface functions in the Microsoft Windows operating system.
System. Windows. Forms. Design Contains classes that support design-time configuration and behavior of Windows Forms components. These classes include: designer classes supported by Windows Forms components (a group of design-time services), uitypeeditor classes used to configure specific property types, and classes used to import ActiveX controls.
System. xml supports standard-based XML processing.
System. xml. schema contains XML classes supported by the standard XML Schema Definition Language (XSD) architecture.
System. xml. serialization contains a class used to serialize objects into documents or streams 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 provides support for extensible style table conversion (XSLT. It supports W3C XSL conversion (XSLT) Version 1.0 recommendations (www.w3.org/tr/xslt ).
You can filter the class library reference documents by language to view a language (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 ".
When you try to call an instance method and the basic object contains a null reference, all instance methods in the class library will cause an instance of nullreferenceexception. This exception may occur in any instance method. This exception is not explicitly listed for each instance method in the reference document.
The class library documentation lists other exceptions caused by each member, as well as descriptions of the conditions for each exception.
All public static members (methods, attributes, fields, and events) in. NET Framework Support concurrent access in a multi-threaded environment. Therefore, any. NET Framework static member can be called from both threads without contention conditions, deadlocks, or faults.
For all classes and structures in. NET Framework, see the "thread security" section in the API reference documentation to determine whether it is thread-safe. If you want to use a non-thread-safe class in a multi-threaded environment, you must use the code that provides the necessary synchronization structure to wrap the instance of this class.
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