BinaryWriter.Write Method (Byte) (System.IO)

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BinaryWriter.Write Method (Byte)
Writes an unsigned byte to the current stream and advances the stream position by one byte.

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

Syntax
Visual Basic (Declaration)
Public Overridable Sub Write ( _
	value As Byte _
)
Visual Basic (Usage)
Dim instance As BinaryWriter
Dim value As Byte

instance.Write(value)
C#
public virtual void Write (
	byte value
)
C++
public:
virtual void Write (
	unsigned char value
)
J#
public void Write (
	byte value
)
JScript
public function Write (
	value : byte
)
XAML
Not applicable.

Parameters

value

The unsigned byte to write.

Exceptions
Exception type Condition

IOException

An I/O error occurs.

ObjectDisposedException

The stream is closed.

Remarks

Because of data formatting conflicts, using this method with the following encodings is not recommended:

  • UTF-7

  • ISO-2022-JP

  • ISCII

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

Example

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.

Visual Basic
Imports System
Imports System.IO

Public Class BinaryRW

    Shared Sub Main()
    
        Dim i As Integer = 0

        ' Create random data to write to the stream.
        Dim writeArray(1000) As Byte
        Dim randomGenerator As New Random()
        randomGenerator.NextBytes(writeArray)

        Dim binWriter As New BinaryWriter(New MemoryStream())
        Dim binReader As New BinaryReader(binWriter.BaseStream)

        Try
        
            ' Write the data to the stream.
            Console.WriteLine("Writing the data.")
            For i = 0 To writeArray.Length - 1
                binWriter.Write(writeArray(i))
            Next i

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

            ' Read and verify the data from the stream.
            For i = 0 To writeArray.Length - 1
                If binReader.ReadByte() <> writeArray(i) Then
                    Console.WriteLine("Error writing the data.")
                    Return
                End If
            Next i
            Console.WriteLine("The data was written and verified.")

        ' Catch the EndOfStreamException and write an error message.
        Catch ex As EndOfStreamException
            Console.WriteLine("Error writing the data: {0}", _
                ex.GetType().Name)
        End Try
    
    End Sub
End Class
C#
using System;
using System.IO;

class BinaryRW
{
    static void Main()
    {
        int i = 0;

        // Create random data to write to the stream.
        byte[] writeArray = new byte[1000];
        new Random().NextBytes(writeArray);

        BinaryWriter binWriter = new BinaryWriter(new MemoryStream());
        BinaryReader binReader = 
            new BinaryReader(binWriter.BaseStream);

        try
        {
            // Write the data to the stream.
            Console.WriteLine("Writing the data.");
            for(i = 0; i < writeArray.Length; i++)
            {
                binWriter.Write(writeArray[i]);
            }

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

            // Read and verify the data from the stream.
            for(i = 0; i < writeArray.Length; i++)
            {
                if(binReader.ReadByte() != writeArray[i])
                {
                    Console.WriteLine("Error writing the data.");
                    return;
                }
            }
            Console.WriteLine("The data was written and verified.");
        }

        // Catch the EndOfStreamException and write an error message.
        catch(EndOfStreamException e)
        {
            Console.WriteLine("Error writing the data.\n{0}",
                e.GetType().Name);
        }
    }
}
C++
using namespace System;
using namespace System::IO;
int main()
{
   int i = 0;
   
   // Create random data to write to the stream.
   array<Byte>^writeArray = gcnew array<Byte>(1000);
   (gcnew Random)->NextBytes( writeArray );
   BinaryWriter^ binWriter = gcnew BinaryWriter( gcnew MemoryStream );
   BinaryReader^ binReader = gcnew BinaryReader( binWriter->BaseStream );
   try
   {
      
      // Write the data to the stream.
      Console::WriteLine( "Writing the data." );
      for ( i = 0; i < writeArray->Length; i++ )
      {
         binWriter->Write( writeArray[ i ] );

      }
      
      // Set the stream position to the beginning of the stream.
      binReader->BaseStream->Position = 0;
      
      // Read and verify the data from the stream.
      for ( i = 0; i < writeArray->Length; i++ )
      {
         if ( binReader->ReadByte() != writeArray[ i ] )
         {
            Console::WriteLine( "Error writing the data." );
            return  -1;
         }

      }
      Console::WriteLine( "The data was written and verified." );
   }
   // Catch the EndOfStreamException and write an error message.
   catch ( EndOfStreamException^ e ) 
   {
      Console::WriteLine( "Error writing the data.\n{0}", e->GetType()->Name );
   }

}
J#
import System.*;
import System.IO.*;

class BinaryRW
{   
    public static void main(String[] args)
    {
        int i = 0;

        // Create random data to write to the stream.
        ubyte writeArray[] = new ubyte[1000];
        new Random().NextBytes(writeArray);

        BinaryWriter binWriter = new BinaryWriter(new MemoryStream());
        BinaryReader binReader = new BinaryReader(binWriter.get_BaseStream());

        try {
            // Write the data to the stream.
            Console.WriteLine("Writing the data.");
            for(i = 0;i < writeArray.length;i++) {
                binWriter.Write(writeArray);                
            } 

            // Set the stream position to the beginning of the stream.
            binReader.get_BaseStream().set_Position(0);

            // Read and verify the data from the stream.
            for(i = 0;i < writeArray.length;i++) {
                if ( binReader.ReadByte() != writeArray[i] ) {
                    Console.WriteLine("Error writing the data.");
                    return;
                }
            }
            Console.WriteLine("The data was written and verified.");
        }
        // Catch the EndOfStreamException and write an error message.
        catch(EndOfStreamException e) {
            Console.WriteLine("Error writing the data.\n{0}",
                e.GetType().get_Name());
        }
    } //main
} //BinaryRW
Platforms

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.

Version Information

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0
See Also