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MemoryStream Class

Creates a stream whose backing store is memory.

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

Namespace:  System.IO
Assembly:  mscorlib (in mscorlib.dll)
[SerializableAttribute]
[ComVisibleAttribute(true)]
public class MemoryStream : Stream

The MemoryStream type exposes the following members.

  Name Description
Public method Supported by the XNA Framework Supported by Portable Class Library MemoryStream() Initializes a new instance of the MemoryStream class with an expandable capacity initialized to zero.
Public method Supported by the XNA Framework Supported by Portable Class Library MemoryStream(Byte[]) Initializes a new non-resizable instance of the MemoryStream class based on the specified byte array.
Public method Supported by the XNA Framework MemoryStream(Int32) Initializes a new instance of the MemoryStream class with an expandable capacity initialized as specified.
Public method Supported by the XNA Framework Supported by Portable Class Library MemoryStream(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 method Supported by the XNA Framework Supported by Portable Class Library MemoryStream(Byte[], Int32, Int32) Initializes a new non-resizable instance of the MemoryStream class based on the specified region (index) of a byte array.
Public method Supported by the XNA Framework Supported by Portable Class Library MemoryStream(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 method Supported by the XNA Framework MemoryStream(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.
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  Name Description
Public property Supported by the XNA Framework Supported by Portable Class Library CanRead Gets a value indicating whether the current stream supports reading. (Overrides Stream.CanRead.)
Public property Supported by the XNA Framework Supported by Portable Class Library CanSeek Gets a value indicating whether the current stream supports seeking. (Overrides Stream.CanSeek.)
Public property Supported by the XNA Framework Supported by Portable Class Library CanTimeout Gets a value that determines whether the current stream can time out. (Inherited from Stream.)
Public property Supported by the XNA Framework Supported by Portable Class Library CanWrite Gets a value indicating whether the current stream supports writing. (Overrides Stream.CanWrite.)
Public property Supported by the XNA Framework Supported by Portable Class Library Capacity Gets or sets the number of bytes allocated for this stream.
Public property Supported by the XNA Framework Supported by Portable Class Library Length Gets the length of the stream in bytes. (Overrides Stream.Length.)
Public property Supported by the XNA Framework Supported by Portable Class Library Position Gets or sets the current position within the stream. (Overrides Stream.Position.)
Public property Supported by the XNA Framework Supported by Portable Class Library 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 property Supported by the XNA Framework Supported by Portable Class Library WriteTimeout Gets or sets a value, in miliseconds, that determines how long the stream will attempt to write before timing out. (Inherited from Stream.)
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  Name Description
Public method Supported by the XNA Framework Supported by Portable Class Library BeginRead Begins an asynchronous read operation. (Inherited from Stream.)
Public method Supported by the XNA Framework Supported by Portable Class Library BeginWrite Begins an asynchronous write operation. (Inherited from Stream.)
Public method Supported by the XNA Framework Close Closes the current stream and releases any resources (such as sockets and file handles) associated with the current stream. (Inherited from Stream.)
Public method CopyTo(Stream) Reads the bytes from the current stream and writes them to the destination stream. (Inherited from Stream.)
Public method 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 method CreateObjRef Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)
Protected method Supported by the XNA Framework CreateWaitHandle Obsolete. Allocates a WaitHandle object. (Inherited from Stream.)
Public method Supported by the XNA Framework Supported by Portable Class Library Dispose() Releases all resources used by the Stream. (Inherited from Stream.)
Protected method Supported by the XNA Framework Supported by Portable Class Library Dispose(Boolean) Releases the unmanaged resources used by the MemoryStream class and optionally releases the managed resources. (Overrides Stream.Dispose(Boolean).)
Public method Supported by the XNA Framework Supported by Portable Class Library EndRead Waits for the pending asynchronous read to complete. (Inherited from Stream.)
Public method Supported by the XNA Framework Supported by Portable Class Library EndWrite Ends an asynchronous write operation. (Inherited from Stream.)
Public method Supported by the XNA Framework Supported by Portable Class Library Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected method Supported by the XNA Framework Supported by Portable Class Library Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method Supported by the XNA Framework Supported by Portable Class Library Flush Overrides Stream.Flush so that no action is performed. (Overrides Stream.Flush().)
Public method Supported by the XNA Framework GetBuffer Returns the array of unsigned bytes from which this stream was created.
Public method Supported by the XNA Framework Supported by Portable Class Library GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method GetLifetimeService Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Public method Supported by the XNA Framework Supported by Portable Class Library GetType Gets the Type of the current instance. (Inherited from Object.)
Public method InitializeLifetimeService Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Protected method Supported by the XNA Framework Supported by Portable Class Library MemberwiseClone() Creates a shallow copy of the current Object. (Inherited from Object.)
Protected method MemberwiseClone(Boolean) Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject.)
Protected method ObjectInvariant Infrastructure. Provides support for a Contract. (Overrides Stream.ObjectInvariant().)
Public method Supported by the XNA Framework Supported by Portable Class Library Read Reads a block of bytes from the current stream and writes the data to a buffer. (Overrides Stream.Read(Byte[], Int32, Int32).)
Public method Supported by the XNA Framework Supported by Portable Class Library ReadByte Reads a byte from the current stream. (Overrides Stream.ReadByte().)
Public method Supported by the XNA Framework Supported by Portable Class Library Seek Sets the position within the current stream to the specified value. (Overrides Stream.Seek(Int64, SeekOrigin).)
Public method Supported by the XNA Framework Supported by Portable Class Library SetLength Sets the length of the current stream to the specified value. (Overrides Stream.SetLength(Int64).)
Public method Supported by the XNA Framework Supported by Portable Class Library ToArray Writes the stream contents to a byte array, regardless of the Position property.
Public method Supported by the XNA Framework Supported by Portable Class Library ToString Returns a string that represents the current object. (Inherited from Object.)
Public method Supported by the XNA Framework Supported by Portable Class Library Write Writes a block of bytes to the current stream using data read from a buffer. (Overrides Stream.Write(Byte[], Int32, Int32).)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteByte Writes a byte to the current stream at the current position. (Overrides Stream.WriteByte(Byte).)
Public method Supported by the XNA Framework Supported by Portable Class Library WriteTo Writes the entire contents of this memory stream to another stream.
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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.

The following code example shows how to read and write data using memory as a backing store.


using System;
using System.IO;
using System.Text;

class MemStream
{
    static void Main()
    {
        int count;
        byte[] byteArray;
        char[] charArray;
        UnicodeEncoding uniEncoding = new UnicodeEncoding();

        // Create the data to write to the stream.
        byte[] firstString = uniEncoding.GetBytes(
            "Invalid file path characters are: ");
        byte[] secondString = uniEncoding.GetBytes(
            Path.GetInvalidPathChars());

        using(MemoryStream memStream = new MemoryStream(100))
        {
            // Write the first string to the stream.
            memStream.Write(firstString, 0 , firstString.Length);

            // Write the second string to the stream, byte by byte.
            count = 0;
            while(count < secondString.Length)
            {
                memStream.WriteByte(secondString[count++]);
            }

            // Write the stream properties to the console.
            Console.WriteLine(
                "Capacity = {0}, Length = {1}, Position = {2}\n",
                memStream.Capacity.ToString(),
                memStream.Length.ToString(),
                memStream.Position.ToString());

            // Set the position to the beginning of the stream.
            memStream.Seek(0, SeekOrigin.Begin);

            // Read the first 20 bytes from the stream.
            byteArray = new byte[memStream.Length];
            count = memStream.Read(byteArray, 0, 20);

            // Read the remaining bytes, byte by byte.
            while(count < memStream.Length)
            {
                byteArray[count++] =
                    Convert.ToByte(memStream.ReadByte());
            }

            // Decode the byte array into a char array
            // and write it to the console.
            charArray = new char[uniEncoding.GetCharCount(
                byteArray, 0, count)];
            uniEncoding.GetDecoder().GetChars(
                byteArray, 0, count, charArray, 0);
            Console.WriteLine(charArray);
        }
    }
}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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