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UnmanagedMemoryStream.Write Method

Writes a block of bytes to the current stream using data from a buffer.

This method is not CLS-compliant.  

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

public override void Write (
	byte[] buffer,
	int offset,
	int count
)
public void Write (
	byte[] buffer, 
	int offset, 
	int count
)
public override function Write (
	buffer : byte[], 
	offset : int, 
	count : int
)
Not applicable.

Parameters

buffer

The byte array from which to copy bytes to the current stream.

offset

The offset in the buffer at which to begin copying bytes to the current stream.

count

The number of bytes to write to the current stream.

Exception typeCondition

ObjectDisposedException

The stream is closed.

NotSupportedException

The underlying memory does not support writing.

- or -

An attempt is made to write to the stream and the CanWrite property is false.

- or -

The count value is greater than the capacity of the stream.

- or -

The position is at the end of the stream capacity.

IOException

An I/O error occurs.

ArgumentOutOfRangeException

One of the specified parameters is less than zero.

ArgumentException

The offset parameter minus the length of the buffer parameter is less than the count parameter.

ArgumentNullException

The buffer parameter is a null reference (Nothing in Visual Basic).

Writing occurs at the current position in the stream.

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 som 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 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

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