FileStream::WriteByte Method (Byte)

 
System_CAPS_noteNote

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

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

public:
virtual void WriteByte(
	unsigned char value
) override

Parameters

value
Type: System::Byte

A byte to write to the stream.

Exception Condition
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.

System_CAPS_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.

For a list of common file and directory operations, see Common I-O Tasks.

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 namespace System;
using namespace System::IO;
int main()
{
   String^ fileName =  "Test@##@.dat";

   // Create random data to write to the file.
   array<Byte>^dataArray = gcnew array<Byte>(100000);
   (gcnew Random)->NextBytes( dataArray );
   FileStream^ fileStream = gcnew 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->Length; i++ )
      {
         if ( dataArray[ i ] != fileStream->ReadByte() )
         {
            Console::WriteLine( "Error writing data." );
            return  -1;
         }

      }
      Console::WriteLine( "The data was written to {0} "
      "and verified.", fileStream->Name );
   }
   finally
   {
      fileStream->Close();
   }

}

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
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