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FileStream.WriteByte Method

Writes a byte to the current position in the file stream.

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

public override void WriteByte (
	byte value
)
public void WriteByte (
	byte value
)
public override function WriteByte (
	value : byte
)

Parameters

value

A byte to write to the stream.

Exception typeCondition

ObjectDisposedException

The stream is closed.

NotSupportedException

The stream does not support writing.

This method overrides WriteByte.

Use WriteByte to write a byte to a FileStream efficiently. If the stream is closed or not writable, an exception will be thrown.

NoteNote

Use the CanWrite property to determine whether the current instance supports writing. For additional information, see CanWrite.

Notes to Implementers The default implementation on Stream creates a new single-byte array and then calls Write. While this is formally correct, it is inefficient. Any stream with an internal buffer should override this method and provide a much more efficient version that reads the buffer directly, avoiding the extra array allocation on every call. The following table lists examples of other typical or related I/O tasks.

To do this...

See the example in this topic...

Create a text file.

How to: Write Text to a File

Write to a text file.

How to: Write Text to a File

Read from a text file.

How to: Read Text from a File

Append text to a file.

How to: Open and Append to a Log File

File.AppendText

FileInfo.AppendText

Rename or move a file.

File.Move

FileInfo.MoveTo

Copy a file.

File.Copy

FileInfo.CopyTo

Get the size of a file.

FileInfo.Length

Get the attributes of a file.

File.GetAttributes

Set the attributes of a file.

File.SetAttributes

Determine if a file exists.

File.Exists

Read from a binary file.

How to: Read and Write to a Newly Created Data File

Write to a binary file.

How to: Read and Write to a Newly Created Data File

Create a directory.

Directory.CreateDirectory

Directory.CreateDirectory

The following code example shows how to write data to a file, byte by byte, and then verify that the data was written correctly.

using System;
using System.IO;

class FStream
{
    static void Main()
    {
        const string fileName = "Test#@@#.dat";

        // Create random data to write to the file.
        byte[] dataArray = new byte[100000];
        new Random().NextBytes(dataArray);

        using(FileStream  
            fileStream = new FileStream(fileName, FileMode.Create))
        {
            // Write the data to the file, byte by byte.
            for(int i = 0; i < dataArray.Length; i++)
            {
                fileStream.WriteByte(dataArray[i]);
            }

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

            // Read and verify the data.
            for(int i = 0; i < fileStream.Length; i++)
            {
                if(dataArray[i] != fileStream.ReadByte())
                {
                    Console.WriteLine("Error writing data.");
                    return;
                }
            }
            Console.WriteLine("The data was written to {0} " +
                "and verified.", fileStream.Name);
        }
    }
}

import System.*;
import System.IO.*;

class FStream
{   
    public static void main(String[] args)
    {
        final String fileName = "Test#@@#.dat";

        // Create random data to write to the file.
        ubyte dataArray[] = new ubyte[100000];
        new Random().NextBytes(dataArray);        

        FileStream fileStream = new FileStream(fileName, FileMode.Create);
        try {
            // Write the data to the file, byte by byte.
            for(int i=0;i < dataArray.length;i++) {
                fileStream.WriteByte(dataArray[i]);
            } 

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

            // Read and verify the data.
            for(int i=0;i < fileStream.get_Length();i++) {
                if ( dataArray[i] != fileStream.ReadByte()  ) {
                    Console.WriteLine("Error writing data.");
                    return;
                }
            } 
            Console.WriteLine("The data was written to {0} "
                + "and verified.", fileStream.get_Name());
        }
        finally {
            fileStream.Dispose();
        }        
    } //main
} //FStream

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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