MemoryStream Class

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Creates a stream whose backing store is memory.

Inheritance Hierarchy

System..::.Object
System.IO..::.Stream
System.IO..::.MemoryStream

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

Syntax

Public Class MemoryStream _
    Inherits Stream
public class MemoryStream : Stream

The MemoryStream type exposes the following members.

Constructors

Name Description
MemoryStream()()() Initializes a new instance of the MemoryStream class with an expandable capacity initialized to zero.
MemoryStream(array<Byte>[]()[]) Initializes a new non-resizable instance of the MemoryStream class based on the specified byte array.
MemoryStream(Int32) Initializes a new instance of the MemoryStream class with an expandable capacity initialized as specified.
MemoryStream(array<Byte>[]()[], Boolean) Initializes a new non-resizable instance of the MemoryStream class based on the specified byte array with the CanWrite property set as specified.
MemoryStream(array<Byte>[]()[], Int32, Int32) Initializes a new non-resizable instance of the MemoryStream class based on the specified region (index) of a byte array.
MemoryStream(array<Byte>[]()[], Int32, Int32, Boolean) Initializes a new non-resizable instance of the MemoryStream class based on the specified region of a byte array, with the CanWrite property set as specified.
MemoryStream(array<Byte>[]()[], Int32, Int32, Boolean, Boolean) Initializes a new instance of the MemoryStream class based on the specified region of a byte array, with the CanWrite property set as specified, and the ability to call GetBuffer set as specified.

Top

Properties

Name Description
CanRead Gets a value indicating whether the current stream supports reading. (Overrides Stream..::.CanRead.)
CanSeek Gets a value indicating whether the current stream supports seeking. (Overrides Stream..::.CanSeek.)
CanTimeout Gets a value that determines whether the current stream can time out. (Inherited from Stream.)
CanWrite Gets a value indicating whether the current stream supports writing. (Overrides Stream..::.CanWrite.)
Capacity Gets or sets the number of bytes allocated for this stream.
Length Gets the length of the stream in bytes. (Overrides Stream..::.Length.)
Position Gets or sets the current position within the stream. (Overrides Stream..::.Position.)
ReadTimeout Gets or sets a value, in miliseconds, that determines how long the stream will attempt to read before timing out. (Inherited from Stream.)
WriteTimeout Gets or sets a value, in miliseconds, that determines how long the stream will attempt to write before timing out. (Inherited from Stream.)

Top

Methods

Name Description
BeginRead Begins an asynchronous read operation. (Inherited from Stream.)
BeginWrite Begins an asynchronous write operation. (Inherited from Stream.)
Close Closes the current stream and releases any resources (such as sockets and file handles) associated with the current stream. (Inherited from Stream.)
CopyTo(Stream) Reads all the bytes from the current stream and writes them to the destination stream. (Inherited from Stream.)
CopyTo(Stream, Int32) Reads all the bytes from the current stream and writes them to a destination stream, using a specified buffer size. (Inherited from Stream.)
CopyToAsync(Stream) Asynchronously reads the bytes from the current stream and writes them to another stream. (Inherited from Stream.)
CopyToAsync(Stream, Int32) Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size. (Inherited from Stream.)
CopyToAsync(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. (Inherited from Stream.)
Dispose()()() Releases all resources used by the Stream. (Inherited from Stream.)
Dispose(Boolean) Releases the unmanaged resources used by the MemoryStream class and optionally releases the managed resources. (Overrides Stream..::.Dispose(Boolean).)
EndRead Waits for the pending asynchronous read to complete. (Inherited from Stream.)
EndWrite Ends an asynchronous write operation. (Inherited from Stream.)
Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Finalize Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Flush Overrides Stream..::.Flush so that no action is performed. (Overrides Stream..::.Flush()()().)
FlushAsync()()() Asynchronously clears all buffers for this stream and causes any buffered data to be written to the underlying device. (Inherited from Stream.)
FlushAsync(CancellationToken) Asynchronously clears all buffers for this stream, and monitors cancellation requests. (Overrides Stream..::.FlushAsync(CancellationToken).)
GetBuffer Returns the array of unsigned bytes from which this stream was created.
GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
GetType Gets the Type of the current instance. (Inherited from Object.)
MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Read Reads a block of bytes from the current stream and writes the data to a buffer. (Overrides Stream..::.Read(array<Byte>[]()[], Int32, Int32).)
ReadAsync(array<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. (Inherited from Stream.)
ReadAsync(array<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. (Overrides Stream..::.ReadAsync(array<Byte>[]()[], Int32, Int32, CancellationToken).)
ReadByte Reads a byte from the current stream. (Overrides Stream..::.ReadByte()()().)
Seek Sets the position within the current stream to the specified value. (Overrides Stream..::.Seek(Int64, SeekOrigin).)
SetLength Sets the length of the current stream to the specified value. (Overrides Stream..::.SetLength(Int64).)
ToArray Writes the stream contents to a byte array, regardless of the Position property.
ToString Returns a string that represents the current object. (Inherited from Object.)
Write Writes a block of bytes to the current stream using data read from a buffer. (Overrides Stream..::.Write(array<Byte>[]()[], Int32, Int32).)
WriteAsync(array<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. (Inherited from Stream.)
WriteAsync(array<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. (Overrides Stream..::.WriteAsync(array<Byte>[]()[], Int32, Int32, CancellationToken).)
WriteByte Writes a byte to the current stream at the current position. (Overrides Stream..::.WriteByte(Byte).)
WriteTo Writes the entire contents of this memory stream to another stream.

Top

Extension Methods

Name Description
AsInputStream (Defined by WindowsRuntimeStreamExtensions.)
AsOutputStream (Defined by WindowsRuntimeStreamExtensions.)
GetWindowsRuntimeBuffer()()() Overloaded. Returns a Windows.Storage.Streams.IBuffer interface that represents the same memory as the specified memory stream. (Defined by WindowsRuntimeBufferExtensions.)
GetWindowsRuntimeBuffer(Int32, Int32) Overloaded. Returns a Windows.Storage.Streams.IBuffer interface that represents a region within the memory that the specified memory stream represents. (Defined by WindowsRuntimeBufferExtensions.)

Top

Remarks

The MemoryStream class creates streams that have memory as a backing store instead of a disk or a network connection. MemoryStream encapsulates data stored as an unsigned byte array that is initialized upon creation of a MemoryStream object, or the array can be created as empty. The encapsulated data is directly accessible in memory. Memory streams can reduce the need for temporary buffers and files in an application.

The current position of a stream is the position at which the next read or write operation could take place. The current position can be retrieved or set through the Seek method. When a new instance of MemoryStream is created, the current position is set to zero.

Memory streams created with an unsigned byte array provide a non-resizable stream of the data. When using a byte array, you can neither append to nor shrink the stream, although you might be able to modify the existing contents depending on the parameters passed into the constructor. Empty memory streams are resizable, and can be written to and read from.

If a MemoryStream object is added to a ResX file or a .resources file, call the GetStream method at runtime to retrieve it.

If a MemoryStream object is serialized to a resource file it will actually be serialized as an UnmanagedMemoryStream. This behavior provides better performance, as well as the ability to get a pointer to the data directly, without having to go through Stream methods.

Version Notes

Windows Phone

ArrayTypeMismatchException is not thrown when your application tries to store Stream.Null in a MemoryStream object.

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Platforms

Windows Phone

Thread Safety

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

See Also

Reference

System.IO Namespace