Namespace System

Classes

Activator

Contains methods to create types of objects locally. This class cannot be inherited.

AggregateException

Initializes a new instance of the AggregateException class with a system-supplied message that describes the error.

AppDomainUnloadedException

The exception that is thrown when an attempt is made to access an unloaded application domain.

ApplicationException

Serves as the base class for application-defined exceptions.

ArgumentException

The exception that is thrown when one of the arguments provided to a method is not valid.

ArgumentNullException

The exception that is thrown when a null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

ArgumentOutOfRangeException

The exception that is thrown when the value of an argument is outside the allowable range of values as defined by the invoked method.

Array

Provides methods for creating, manipulating, searching, and sorting arrays, thereby serving as the base class for all arrays in the common language runtime.

Attribute

Represents the base class for custom attributes.

AttributeUsageAttribute

Specifies the usage of another attribute class. This class cannot be inherited.

BitConverter

Converts base data types to an array of bytes, and an array of bytes to base data types.

CLSCompliantAttribute

Indicates whether a program element is compliant with the Common Language Specification (CLS). This class cannot be inherited.

Console

Writes the specified data, followed by the current line terminator, to the standard output stream.

Convert

Converts a base data type to another base data type.

DBNull

Represents a nonexistent value. This class cannot be inherited.

Delegate

Represents a delegate, which is a data structure that refers to a static method or to a class instance and an instance method of that class.

Enum

Provides the base class for enumerations.

Environment

Provides information about, and means to manipulate, the current environment and platform. This class cannot be inherited.

EventArgs

Represents the base class for classes that contain event data, and provides a value to use for events that do not include event data.

Exception

Represents errors that occur during application execution.

FlagsAttribute

Indicates that an enumeration can be treated as a bit field; that is, a set of flags.

FormatException

The exception that is thrown for invalid casting or explicit conversion.

GC

Controls the system garbage collector, a service that automatically reclaims unused memory.

IndexOutOfRangeException

The exception that is thrown when an attempt is made to access an element of an array with an index that is outside the bounds of the array. This class cannot be inherited.

InvalidCastException

The exception that is thrown for invalid casting or explicit conversion.

InvalidOperationException

The exception that is thrown when a method call is invalid for the object's current state.

MarshalByRefObject

Enables access to objects across application domain boundaries in applications that support remoting.

Math

Provides constants and static methods for trigonometric, logarithmic, and other common mathematical functions.

MTAThreadAttribute

Indicates that the COM threading model for an application is multithreaded apartment (MTA).

MulticastDelegate

Represents a multicast delegate; that is, a delegate that can have more than one element in its invocation list.

NonSerializedAttribute

Indicates that a field of a serializable class should not be serialized. This class cannot be inherited.

NotImplementedException

The exception that is thrown when a requested method or operation is not implemented.

NotSupportedException

The exception that is thrown when an invoked method is not supported, or when there is an attempt to read, seek, or write to a stream that does not support the invoked functionality.

NullReferenceException

The exception that is thrown when there is an attempt to dereference a null object reference.

Supports all classes in the .NET Framework class hierarchy and provides low-level services to derived classes. This is the ultimate base class of all classes in the .NET Framework; it is the root of the type hierarchy.

ObjectDisposedException

The exception that is thrown when an operation is performed on a disposed object.

ObsoleteAttribute

Marks the program elements that are no longer in use. This class cannot be inherited.

OutOfMemoryException

The exception that is thrown when there is not enough memory to continue the execution of a program.

ParamArrayAttribute

Indicates that a method will allow a variable number of arguments in its invocation. This class cannot be inherited.

PlatformNotSupportedException

The exception that is thrown when a feature does not run on a particular platform.

Random

Represents a random number generator, a device that produces a sequence of numbers that meet certain statistical requirements for randomness.

SerializableAttribute

Indicates that a class can be serialized. This class cannot be inherited.

STAThreadAttribute

Indicates that the COM threading model for an application is single-threaded apartment (STA).

String

Represents text as a sequence of UTF-16 code units.

SystemException

Serves as the base class for system exceptions namespace.

TimeoutException

The exception that is thrown when the time allotted for a process or operation has expired.

Type

Represents type declarations: class types, interface types, array types, value types, enumeration types, type parameters, generic type definitions, and open or closed constructed generic types.

Uri

Provides an object representation of a uniform resource identifier (URI) and easy access to the parts of the URI.

ValueType

Provides the base class for value types.

Version

Represents the version number of an assembly, operating system, or the common language runtime. This class cannot be inherited.

WeakReference

Represents a weak reference, which references an object while still allowing that object to be reclaimed by garbage collection.

Structs

Boolean

Represents a Boolean value.

Byte

Represents an 8-bit unsigned integer.

Char

Represents a character as a UTF-16 code unit.

DateTime

Represents an instant in time, typically expressed as a date and time of day.

Double

Represents a double-precision floating-point number.

Guid

Represents a globally unique identifier (GUID).

Int16

Represents a 16-bit signed integer.

Int32

Represents a 32-bit signed integer.

Int64

Represents a 64-bit signed integer.

IntPtr

A platform-specific type that is used to represent a pointer or a handle.

RuntimeArgumentHandle

This value type is used for constructing System.ArgIterator.

RuntimeFieldHandle

Represents a field using an internal metadata token.

RuntimeMethodHandle

RuntimeMethodHandle is a handle to the internal metadata representation of a method.

RuntimeTypeHandle

Represents a type using an internal metadata token.

SByte

Represents an 8-bit signed integer.

Single

Represents a single-precision floating-point number.

SpanByte

Provides a type- and memory-safe representation of a contiguous region of arbitrary byte array

TimeSpan

Represents a time interval.

TypedReference

Describes objects that contain both a managed pointer to a location and a runtime representation of the type that may be stored at that location.

UInt16

Represents a 16-bit unsigned integer.

UInt32

Represents a 32-bit ununsigned integer.

UInt64

Represents a 64-bit ununsigned integer.

UIntPtr

A platform-specific type that is used to represent a pointer or a handle.

Void

Specifies a return value type for a method that does not return a value.

Interfaces

IAsyncResult

Represents the status of an asynchronous operation.

ICloneable

Defines an interface indicating that an object may be cloned.

IComparable

Defines a generalized type-specific comparison method that a value type or class implements to order or sort its instances.

ICustomFormatter

Defines a method that supports custom formatting of the value of an object.

IDisposable

Defines a method to release allocated resources.

IFormatProvider

Provides a mechanism for retrieving an object to control formatting.

IFormattable

Provides functionality to format the value of an object into a string representation.

IServiceProvider

Defines a mechanism for retrieving a service object; that is, an object that provides custom support to other objects.

Enums

AttributeTargets

Specifies the application elements on which it is valid to apply an attribute.

Base64FormattingOptions

Specifies whether relevant Convert.ToBase64CharArray and Convert.ToBase64String methods insert line breaks in their output.

DateTimeKind

Specifies whether a DateTime object represents a local time, a Coordinated Universal Time (UTC), or is not specified as either local time or UTC.

DayOfWeek

Specifies the day of the week.

TypeCode

Specifies the type of an object.

Uri.Flags

Defines flags kept in m_Flags variable.

UriHostNameType

Defines host name types for the http and https protocols. method.

UriKind

Defines the kinds of Uris for the IsWellFormedUriString(String, UriKind) method and several Uri methods.

Namespace System

Classes

Structs

Interfaces

Enums

Delegates