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BinaryReader.ReadBytes Method

Reads count bytes from the current stream into a byte array and advances the current position by count bytes.

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

'Declaration
Public Overridable Function ReadBytes ( _
	count As Integer _
) As Byte()
'Usage
Dim instance As BinaryReader 
Dim count As Integer 
Dim returnValue As Byte()

returnValue = instance.ReadBytes(count)

Parameters

count
Type: System.Int32

The number of bytes to read.

Return Value

Type: System.Byte()
A byte array containing data read from the underlying stream. This might be less than the number of bytes requested if the end of the stream is reached.

ExceptionCondition
IOException

An I/O error occurs.

ObjectDisposedException

The stream is closed.

ArgumentOutOfRangeException

count is negative.

BinaryReader does not restore the file position after an unsuccessful read.

For a list of common I/O tasks, see Common I/O Tasks.

The following code example shows how to write binary data using memory as a backing store, and then verify that the data was written correctly.

Imports System
Imports System.IO

Public Class BinaryRW

    Shared Sub Main()

        Const upperBound As Integer = 1000

        ' Create random data to write to the stream. 
        Dim dataArray(upperBound) As Byte
        Dim randomGenerator As New Random
        randomGenerator.NextBytes(dataArray)

        Dim binWriter As New BinaryWriter(New MemoryStream())

        ' Write the data to the stream.
        Console.WriteLine("Writing the data.")
        binWriter.Write(dataArray)

        ' Create the reader using the stream from the writer. 
        Dim binReader As New BinaryReader(binWriter.BaseStream)

        ' Set the stream position to the beginning of the stream.
        binReader.BaseStream.Position = 0

        ' Read and verify the data. 
        Dim verifyArray() As Byte = _
            binReader.ReadBytes(dataArray.Length)
        If verifyArray.Length <> dataArray.Length Then
            Console.WriteLine("Error writing the data.")
            Return 
        End If 
        For i As Integer = 0 To upperBound
            If verifyArray(i) <> dataArray(i) Then
                Console.WriteLine("Error writing the data.")
                Return 
            End If 
        Next i
        Console.WriteLine("The data was written and verified.")

    End Sub 
End Class

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0
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