Partager via


MemoryStream Class

Microsoft Silverlight will reach end of support after October 2021. Learn more.

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

'Declaration
<ComVisibleAttribute(True)> _
Public Class MemoryStream _
    Inherits Stream
[ComVisibleAttribute(true)]
public class MemoryStream : Stream

The MemoryStream type exposes the following members.

Constructors

  Name Description
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 MemoryStream() Initializes a new instance of the MemoryStream class with an expandable capacity initialized to zero.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 MemoryStream(array<Byte[]) Initializes a new non-resizable instance of the MemoryStream class based on the specified byte array.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 MemoryStream(Int32) Initializes a new instance of the MemoryStream class with an expandable capacity initialized as specified.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 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.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 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.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 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.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 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
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 CanRead Gets a value indicating whether the current stream supports reading. (Overrides Stream.CanRead.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 CanSeek Gets a value indicating whether the current stream supports seeking. (Overrides Stream.CanSeek.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 CanTimeout Gets a value that determines whether the current stream can time out. (Inherited from Stream.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 CanWrite Gets a value indicating whether the current stream supports writing. (Overrides Stream.CanWrite.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 Capacity Gets or sets the number of bytes allocated for this stream.
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 Length Gets the length of the stream in bytes. (Overrides Stream.Length.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 Position Gets or sets the current position within the stream. (Overrides Stream.Position.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 ReadTimeout Gets or sets a value, in miliseconds, that determines how long the stream will attempt to read before timing out. (Inherited from Stream.)
Public propertySupported by Silverlight for Windows PhoneSupported by Xbox 360 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
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 BeginRead Begins an asynchronous read operation. (Inherited from Stream.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 BeginWrite Begins an asynchronous write operation. (Inherited from Stream.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 Close Closes the current stream and releases any resources (such as sockets and file handles) associated with the current stream. (Inherited from Stream.)
Public methodSupported by Silverlight for Windows Phone CopyTo(Stream) Reads all the bytes from the current stream and writes them to the destination stream. (Inherited from Stream.)
Public methodSupported by Silverlight for Windows Phone 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.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 Dispose() Releases all resources used by the Stream. (Inherited from Stream.)
Protected methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 Dispose(Boolean) Releases the unmanaged resources used by the MemoryStream class and optionally releases the managed resources. (Overrides Stream.Dispose(Boolean).)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 EndRead Waits for the pending asynchronous read to complete. (Inherited from Stream.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 EndWrite Ends an asynchronous write operation. (Inherited from Stream.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 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.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 Flush Overrides Stream.Flush so that no action is performed. (Overrides Stream.Flush().)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetBuffer Returns the array of unsigned bytes from which this stream was created.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 GetType Gets the Type of the current instance. (Inherited from Object.)
Protected methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 Read Reads a block of bytes from the current stream and writes the data to a buffer. (Overrides Stream.Read(array<Byte[], Int32, Int32).)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 ReadByte Reads a byte from the current stream. (Overrides Stream.ReadByte().)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 Seek Sets the position within the current stream to the specified value. (Overrides Stream.Seek(Int64, SeekOrigin).)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 SetLength Sets the length of the current stream to the specified value. (Overrides Stream.SetLength(Int64).)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 ToArray Writes the stream contents to a byte array, regardless of the Position property.
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 ToString Returns a string that represents the current object. (Inherited from Object.)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 Write Writes a block of bytes to the current stream using data read from a buffer. (Overrides Stream.Write(array<Byte[], Int32, Int32).)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 WriteByte Writes a byte to the current stream at the current position. (Overrides Stream.WriteByte(Byte).)
Public methodSupported by Silverlight for Windows PhoneSupported by Xbox 360 WriteTo Writes the entire contents of this memory stream to another stream.

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.

Platform Notes

Silverlight for Windows Phone Silverlight for Windows Phone

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

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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