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UnmanagedMemoryStream Class
Visual Studio 2010
Provides access to unmanaged blocks of memory from managed code.
System.Object
System.MarshalByRefObject
System.IO.Stream
System.IO.UnmanagedMemoryStream
System.IO.MemoryMappedFiles.MemoryMappedViewStream
System.MarshalByRefObject
System.IO.Stream
System.IO.UnmanagedMemoryStream
System.IO.MemoryMappedFiles.MemoryMappedViewStream
Assembly: mscorlib (in mscorlib.dll)
The UnmanagedMemoryStream type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | UnmanagedMemoryStream | Initializes a new instance of the UnmanagedMemoryStream class. |
![]() | UnmanagedMemoryStream(Byte*, Int64) | Initializes a new instance of the UnmanagedMemoryStream class using the specified location and memory length. |
![]() | UnmanagedMemoryStream(SafeBuffer, Int64, Int64) | Initializes a new instance of the UnmanagedMemoryStream class in a safe buffer with a specified offset and length. |
![]() | UnmanagedMemoryStream(Byte*, Int64, Int64, FileAccess) | Initializes a new instance of the UnmanagedMemoryStream class using the specified location, memory length, total amount of memory, and file access values. |
![]() | UnmanagedMemoryStream(SafeBuffer, Int64, Int64, FileAccess) | Initializes a new instance of the UnmanagedMemoryStream class in a safe buffer with a specified offset, length, and file access. |
| Name | Description | |
|---|---|---|
![]() | CanRead | Gets a value indicating whether a stream supports reading. (Overrides Stream.CanRead.) |
![]() | CanSeek | Gets a value indicating whether a 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 a stream supports writing. (Overrides Stream.CanWrite.) |
![]() | Capacity | Gets the stream length (size) or the total amount of memory assigned to a stream (capacity). |
![]() | Length | Gets the length of the data in a stream. (Overrides Stream.Length.) |
![]() | Position | Gets or sets the current position in a stream. (Overrides Stream.Position.) |
![]() | PositionPointer | Gets or sets a byte pointer to a stream based on the current position in the stream. |
![]() | 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 UnmanagedMemoryStream 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 the Flush method so that no action is performed. (Overrides Stream.Flush.) |
![]() | 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.) |
![]() | Initialize(Byte*, Int64, Int64, FileAccess) | Initializes a new instance of the UnmanagedMemoryStream class by using a pointer to an unmanaged memory location. |
![]() | Initialize(SafeBuffer, Int64, Int64, FileAccess) | Initializes a new instance of the UnmanagedMemoryStream class in a safe buffer with a specified offset, length, and file access. |
![]() | 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. (Inherited from Stream.) |
![]() | Read | Reads the specified number of bytes into the specified array. (Overrides Stream.Read(Byte(), Int32, Int32).) |
![]() | ReadByte | Reads a byte from a stream and advances the position within the stream by one byte, or returns -1 if at the end of the stream. (Overrides Stream.ReadByte.) |
![]() | Seek | Sets the current position of the current stream to the given value. (Overrides Stream.Seek(Int64, SeekOrigin).) |
![]() | SetLength | Sets the length of a stream to a specified value. (Overrides Stream.SetLength(Int64).) |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
![]() | Write | Writes a block of bytes to the current stream using data from a buffer. (Overrides Stream.Write(Byte(), Int32, Int32).) |
![]() | WriteByte | Writes a byte to the current position in the file stream. (Overrides Stream.WriteByte(Byte).) |
The following code example demonstrates how to read from and write to unmanaged memory using the UnmanagedMemoryStream class. A block of unmanaged memory is allocated and de-allocated using the Marshal class.
// Note: you must compile this sample using the unsafe flag. // From the command line, type the following: csc sample.cs /unsafe using System; using System.IO; using System.Text; using System.Runtime.InteropServices; unsafe class TestWriter { static void Main() { // Create some data to read and write. byte[] message = UnicodeEncoding.Unicode.GetBytes("Here is some data."); // Allocate a block of unmanaged memory and return an IntPtr object. IntPtr memIntPtr = Marshal.AllocHGlobal(message.Length); // Get a byte pointer from the IntPtr object. byte* memBytePtr = (byte*) memIntPtr.ToPointer(); // Create an UnmanagedMemoryStream object using a pointer to unmanaged memory. UnmanagedMemoryStream writeStream = new UnmanagedMemoryStream(memBytePtr, message.Length, message.Length, FileAccess.Write); // Write the data. writeStream.Write(message, 0, message.Length); // Close the stream. writeStream.Close(); // Create another UnmanagedMemoryStream object using a pointer to unmanaged memory. UnmanagedMemoryStream readStream = new UnmanagedMemoryStream(memBytePtr, message.Length, message.Length, FileAccess.Read); // Create a byte array to hold data from unmanaged memory. byte[] outMessage = new byte[message.Length]; // Read from unmanaged memory to the byte array. readStream.Read(outMessage, 0, message.Length); // Close the stream. readStream.Close(); // Display the data to the console. Console.WriteLine(UnicodeEncoding.Unicode.GetString(outMessage)); // Free the block of unmanaged memory. Marshal.FreeHGlobal(memIntPtr); Console.ReadLine(); } }
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.
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