MemoryStream Class
Creates a stream whose backing store is memory.
Assembly: mscorlib (in mscorlib.dll)
The MemoryStream type exposes the following members.
| Name | Description | |
|---|---|---|
![]() ![]() ![]() | MemoryStream | Initializes a new instance of the MemoryStream class with an expandable capacity initialized to zero. |
![]() ![]() ![]() | MemoryStream(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(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(Byte(), Int32, Int32) | Initializes a new non-resizable instance of the MemoryStream class based on the specified region (index) of a byte array. |
![]() ![]() ![]() | 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. |
![]() ![]() | 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. |
| 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.) |
| 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 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.) |
![]() | 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.) |
![]() ![]() | CreateWaitHandle | Obsolete. Allocates a WaitHandle object. (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 it is reclaimed by garbage collection. (Inherited from Object.) |
![]() ![]() ![]() | Flush | Overrides Stream.Flush so that no action is performed. (Overrides Stream.Flush.) |
![]() ![]() | 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.) |
![]() | GetLifetimeService | Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.) |
![]() ![]() ![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | InitializeLifetimeService | Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.) |
![]() ![]() ![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | MemberwiseClone(Boolean) | Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject.) |
![]() | ObjectInvariant | Infrastructure. Provides support for a Contract. (Overrides Stream.ObjectInvariant.) |
![]() ![]() ![]() | Read | Reads a block of bytes from the current stream and writes the data to a buffer. (Overrides Stream.Read(Byte(), Int32, Int32).) |
![]() ![]() ![]() | 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(Byte(), Int32, Int32).) |
![]() ![]() ![]() | 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. |
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.
Imports System Imports System.IO Imports System.Text Module MemStream Sub Main() Dim count As Integer Dim byteArray As Byte() Dim charArray As Char() Dim uniEncoding As New UnicodeEncoding() ' Create the data to write to the stream. Dim firstString As Byte() = _ uniEncoding.GetBytes("Invalid file path characters are: ") Dim secondString As Byte() = _ uniEncoding.GetBytes(Path.GetInvalidPathChars()) Dim memStream As New MemoryStream(100) Try ' 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)) count += 1 End While ' Write the stream properties to the console. Console.WriteLine( _ "Capacity = {0}, Length = {1}, Position = {2}", _ memStream.Capacity.ToString(), _ memStream.Length.ToString(), _ memStream.Position.ToString()) ' Set the stream position to the beginning of the stream. memStream.Seek(0, SeekOrigin.Begin) ' Read the first 20 bytes from the stream. byteArray = _ New Byte(CType(memStream.Length, Integer)){} count = memStream.Read(byteArray, 0, 20) ' Read the remaining Bytes, Byte by Byte. While(count < memStream.Length) byteArray(count) = _ Convert.ToByte(memStream.ReadByte()) count += 1 End While ' 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) Finally memStream.Close() End Try End Sub End Module
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.

