MemoryStream Class

July 28, 2014

Creates a stream whose backing store is memory.

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

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

'Declaration
Public Class MemoryStream _
	Inherits Stream

The MemoryStream type exposes the following members.

  NameDescription
Public methodMemoryStreamInitializes a new instance of the MemoryStream class with an expandable capacity initialized to zero.
Public methodMemoryStream(Byte())Initializes a new non-resizable instance of the MemoryStream class based on the specified byte array.
Public methodMemoryStream(Int32)Initializes a new instance of the MemoryStream class with an expandable capacity initialized as specified.
Public methodMemoryStream(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 methodMemoryStream(Byte(), Int32, Int32)Initializes a new non-resizable instance of the MemoryStream class based on the specified region (index) of a byte array.
Public methodMemoryStream(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 methodMemoryStream(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

  NameDescription
Public propertyCanReadGets a value indicating whether the current stream supports reading. (Overrides Stream.CanRead.)
Public propertyCanSeekGets a value indicating whether the current stream supports seeking. (Overrides Stream.CanSeek.)
Public propertyCanTimeoutGets a value that determines whether the current stream can time out. (Inherited from Stream.)
Public propertyCanWriteGets a value indicating whether the current stream supports writing. (Overrides Stream.CanWrite.)
Public propertyCapacityGets or sets the number of bytes allocated for this stream.
Public propertyLengthGets the length of the stream in bytes. (Overrides Stream.Length.)
Public propertyPositionGets or sets the current position within the stream. (Overrides Stream.Position.)
Public propertyReadTimeoutGets or sets a value, in miliseconds, that determines how long the stream will attempt to read before timing out. (Inherited from Stream.)
Public propertyWriteTimeoutGets or sets a value, in miliseconds, that determines how long the stream will attempt to write before timing out. (Inherited from Stream.)
Top

  NameDescription
Public methodBeginReadBegins an asynchronous read operation. (Inherited from Stream.)
Public methodBeginWriteBegins an asynchronous write operation. (Inherited from Stream.)
Public methodCloseCloses the current stream and releases any resources (such as sockets and file handles) associated with the current stream. (Inherited from Stream.)
Public methodCopyTo(Stream)Reads all the bytes from the current stream and writes them to the destination stream. (Inherited from 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. (Inherited from Stream.)
Public methodCopyToAsync(Stream)Asynchronously reads the bytes from the current stream and writes them to another stream. (Inherited from Stream.)
Public methodCopyToAsync(Stream, Int32)Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size. (Inherited from Stream.)
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. (Inherited from Stream.)
Public methodDisposeReleases all resources used by the Stream. (Inherited from Stream.)
Protected methodDispose(Boolean)Releases the unmanaged resources used by the MemoryStream class and optionally releases the managed resources. (Overrides Stream.Dispose(Boolean).)
Public methodEndReadWaits for the pending asynchronous read to complete. (Inherited from Stream.)
Public methodEndWriteEnds an asynchronous write operation. (Inherited from Stream.)
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 methodFlushOverrides Stream.Flush so that no action is performed. (Overrides Stream.Flush.)
Public methodFlushAsyncAsynchronously clears all buffers for this stream and causes any buffered data to be written to the underlying device. (Inherited from Stream.)
Public methodFlushAsync(CancellationToken)Asynchronously clears all buffers for this stream, and monitors cancellation requests. (Overrides Stream.FlushAsync(CancellationToken).)
Public methodGetBufferReturns the array of unsigned bytes from which this stream was created.
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 methodReadReads a block of bytes from the current stream and writes the data to a buffer. (Overrides Stream.Read(Byte(), Int32, Int32).)
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. (Inherited from Stream.)
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. (Overrides Stream.ReadAsync(Byte(), Int32, Int32, CancellationToken).)
Public methodReadByteReads a byte from the current stream. (Overrides Stream.ReadByte.)
Public methodSeekSets the position within the current stream to the specified value. (Overrides Stream.Seek(Int64, SeekOrigin).)
Public methodSetLengthSets the length of the current stream to the specified value. (Overrides Stream.SetLength(Int64).)
Public methodToArrayWrites the stream contents to a byte array, regardless of the Position property.
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodWriteWrites a block of bytes to the current stream using data read from a buffer. (Overrides Stream.Write(Byte(), Int32, Int32).)
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. (Inherited from Stream.)
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. (Overrides Stream.WriteAsync(Byte(), Int32, Int32, CancellationToken).)
Public methodWriteByteWrites a byte to the current stream at the current position. (Overrides Stream.WriteByte(Byte).)
Public methodWriteToWrites the entire contents of this memory stream to another stream.
Top

  NameDescription
Public Extension MethodAsInputStream (Defined by WindowsRuntimeStreamExtensions.)
Public Extension MethodAsOutputStream (Defined by WindowsRuntimeStreamExtensions.)
Public Extension MethodGetWindowsRuntimeBufferOverloaded. Returns a Windows.Storage.Streams.IBuffer interface that represents the same memory as the specified memory stream. (Defined by WindowsRuntimeBufferExtensions.)
Public Extension MethodGetWindowsRuntimeBuffer(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

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.

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