C# FileStream Read

Description

FileStream Read Reads a block of bytes from the stream and writes the data in a given buffer.

Syntax

FileStream.Read has the following syntax.

public override int Read(
  byte[] array,//  w  w w  . ja  va  2 s .c  o  m
  int offset,
  int count
)

Parameters

FileStream.Read has the following parameters.

• array - When this method returns, contains the specified byte array with the values between offset and (offset + count - 1) replaced by the bytes read from the current source.
• offset - The byte offset in array at which the read bytes will be placed.
• count - The maximum number of bytes to read.

Returns

FileStream.Read method returns The total number of bytes read into the buffer. This might be less than the number of bytes requested if that number of bytes are not currently available, or zero if the end of the stream is reached.

Example

The following example reads the contents from a FileStream and writes it into another FileStream.

/* ww  w.  j a  va  2  s .co  m*/
using System;
using System.IO;

class Test
{
    public static void Main()
    {
        string pathSource = @"c:\tests\source.txt";
        string pathNew = @"c:\tests\newfile.txt";

        using (FileStream fsSource = new FileStream(pathSource, FileMode.Open, FileAccess.Read))
        {

            byte[] bytes = new byte[fsSource.Length];
            int numBytesToRead = (int)fsSource.Length;
            while (numBytesToRead > 0)
            {
                int n = fsSource.Read(bytes, 3, numBytesToRead);
                Console.WriteLine(bytes.Length);
                if (n == 0)
                    break;
            }
        }
    }
}