Stream Class

July 28, 2014

Provides a generic view of a sequence of bytes.

Namespace:  System.IO
Assembly:  mscorlib (in mscorlib.dll)

public abstract class Stream : IDisposable

The Stream type exposes the following members.

  NameDescription
Protected methodStreamInitializes a new instance of the Stream class.
Top

  NameDescription
Public propertyCanReadWhen overridden in a derived class, gets a value indicating whether the current stream supports reading.
Public propertyCanSeekWhen overridden in a derived class, gets a value indicating whether the current stream supports seeking.
Public propertyCanTimeoutGets a value that determines whether the current stream can time out.
Public propertyCanWriteWhen overridden in a derived class, gets a value indicating whether the current stream supports writing.
Public propertyLengthWhen overridden in a derived class, gets the length in bytes of the stream.
Public propertyPositionWhen overridden in a derived class, gets or sets the position within the current stream.
Public propertyReadTimeoutGets or sets a value, in miliseconds, that determines how long the stream will attempt to read before timing out.
Public propertyWriteTimeoutGets or sets a value, in miliseconds, that determines how long the stream will attempt to write before timing out.
Top

  NameDescription
Public methodBeginReadBegins an asynchronous read operation.
Public methodBeginWriteBegins an asynchronous write operation.
Public methodCloseCloses the current stream and releases any resources (such as sockets and file handles) associated with the current stream.
Public methodCopyTo(Stream)Reads all the bytes from the current stream and writes them to the destination stream.
Public methodCopyTo(Stream, Int32)Reads all the bytes from the current stream and writes them to a destination stream, using a specified buffer size.
Public methodCopyToAsync(Stream)Asynchronously reads the bytes from the current stream and writes them to another stream.
Public methodCopyToAsync(Stream, Int32)Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size.
Public methodCopyToAsync(Stream, Int32, CancellationToken)Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size and cancellation token.
Public methodDispose()Releases all resources used by the Stream.
Protected methodDispose(Boolean)Releases the unmanaged resources used by the Stream and optionally releases the managed resources.
Public methodEndReadWaits for the pending asynchronous read to complete.
Public methodEndWriteEnds an asynchronous write operation.
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodFlushWhen overridden in a derived class, clears all buffers for this stream and causes any buffered data to be written to the underlying device.
Public methodFlushAsync()Asynchronously clears all buffers for this stream and causes any buffered data to be written to the underlying device.
Public methodFlushAsync(CancellationToken)Asynchronously clears all buffers for this stream, causes any buffered data to be written to the underlying device, and monitors cancellation requests.
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodReadWhen overridden in a derived class, reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.
Public methodReadAsync(Byte[], Int32, Int32)Asynchronously reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.
Public methodReadAsync(Byte[], Int32, Int32, CancellationToken)Asynchronously reads a sequence of bytes from the current stream, advances the position within the stream by the number of bytes read, and monitors cancellation requests.
Public methodReadByteReads a byte from the stream and advances the position within the stream by one byte, or returns -1 if at the end of the stream.
Public methodSeekWhen overridden in a derived class, sets the position within the current stream.
Public methodSetLengthWhen overridden in a derived class, sets the length of the current stream.
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodWriteWhen overridden in a derived class, writes a sequence of bytes to the current stream and advances the current position within this stream by the number of bytes written.
Public methodWriteAsync(Byte[], Int32, Int32)Asynchronously writes a sequence of bytes to the current stream and advances the current position within this stream by the number of bytes written.
Public methodWriteAsync(Byte[], Int32, Int32, CancellationToken)Asynchronously writes a sequence of bytes to the current stream, advances the current position within this stream by the number of bytes written, and monitors cancellation requests.
Public methodWriteByteWrites a byte to the current position in the stream and advances the position within the stream by one byte.
Top

  NameDescription
Public fieldStatic memberNullA Stream with no backing store.
Top

Streams involve three fundamental operations:

  1. You can read from streams. Reading is the transfer of data from a stream into a data structure, such as an array of bytes.

  2. You can write to streams. Writing is the transfer of data from a data structure into a stream.

  3. Streams can support seeking. Seeking is the querying and modifying of the current position within a stream. Seek capability depends on the kind of backing store a stream has. For example, network streams have no unified concept of a current position, and therefore typically do not support seeking.

Stream is the abstract base class of all streams. A stream is an abstraction of a sequence of bytes, such as a file, an input/output device, an inter-process communication pipe, or a TCP/IP socket. The Stream class and its derived classes provide a generic view of these different types of input and output, isolating the programmer from the specific details of the operating system and the underlying devices.

Depending on the underlying data source or repository, streams might support only some of these capabilities. An application can query a stream for its capabilities by using the CanRead, CanWrite, and CanSeek properties.

The Read and Write methods read and write data in a variety of formats. For streams that support seeking, use the Seek and SetLength methods and the Position and Length properties to query and modify the current position and length of a stream.

Some stream implementations perform local buffering of the underlying data to improve performance. For such streams, the Flush method can be used to clear any internal buffers and ensure that all data has been written to the underlying data source or repository.

Calling Close on a Stream flushes any buffered data, essentially calling Flush for you. Close also releases operating system resources such as file handles, network connections, or memory used for any internal buffering.

If you need a stream with no backing store (also known as a bit bucket), use Null.

Notes to Implementers

When implementing a derived class of Stream, you must provide implementations for the Read and Write methods. The asynchronous methods BeginRead, EndRead, BeginWrite, and EndWrite are implemented through the synchronous methods Read and Write. Similarly, your implementations of Read and Write will work correctly with the asynchronous methods. The default implementations of ReadByte and WriteByte create a new single-element byte array, and then call your implementations of Read and Write. When deriving from Stream, if you have an internal byte buffer, it is strongly recommended that you override these methods to access your internal buffer for substantially better performance. You must also provide implementations of CanRead, CanSeek, CanWrite, Flush, Length, Position, Seek, and SetLength.

Do not override the Close method, instead, put all of the Stream cleanup logic in the Dispose method.

TopicLocation
How to: Write Text to a File.NET Framework: Programming Fundamentals
How to: Read Text from a File.NET Framework: Programming Fundamentals
How to: Write Text to a File.NET Framework: Programming Fundamentals
How to: Read Text from a File.NET Framework: Programming Fundamentals
How to: Write Text to a File

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Show:
© 2014 Microsoft