//Define the Decorated Stream Object.

//Define the StreamDecorator class which "decorates" the built-in Stream .NET class.
//The StreamDecorator class inherits from the Stream base class and implements the standard class functionality.
public class StreamDecorator : Stream
{
Stream _mStream;
int _mTotalBytesRead;
int _mNumBytesToRead;
int _mMaxBytesToRead = 5;
string _mReadText = string.Empty;

public StreamDecorator(Stream s)
{
_mStream = s;
_mTotalBytesRead = 0;
_mNumBytesToRead = (int) s.Length;
}

public override bool CanRead
{
get { return _mStream.CanRead; }
}

public override bool CanSeek
{
get { return _mStream.CanSeek; }
}

public override bool CanWrite
{
get { return _mStream.CanWrite; }
}

public override void Flush()
{
_mStream.Flush();
}

public override long Length
{
get { return _mStream.Length; }
}

public override long Position
{
get { return _mStream.Position; }
set { _mStream.Position = Position; }
}

public override int Read(byte[] buffer, int offset, int count)
{
return _mStream.Read(buffer, offset, count);
}

public override long Seek(long offset, SeekOrigin origin)
{
return _mStream.Seek(offset, origin);
}

public override void SetLength(long value)
{
_mStream.SetLength(value);
}

public override void Write(byte[] buffer, int offset, int count)
{
_mStream.Write(buffer, offset, count);
}

//The StreamDecorator class then defines additional operations that form part of the new "decorated" class.
//These new operations are not available in the standard Stream class.
public string ReadText
{
get { return _mReadText; }
}

public int MaxBytesToRead
{
get { return _mMaxBytesToRead; }
set { _mMaxBytesToRead = value; }
}

public int NumBytesToRead
{
get { return _mNumBytesToRead; }
}

public int TotalBytesRead
{
get { return _mTotalBytesRead; }
}

public intpublic int Read(byte[] buffer)
{
int numBytesRead;
var maxBytesToRead = _mMaxBytesToRead;
UTF7Encoding byteString = new UTF7Encoding();
if (_mNumBytesToRead < maxBytesToRead)
{
maxBytesToRead = NumBytesToRead;
}

numBytesRead = _mStream.Read(buffer, _mTotalBytesRead, maxBytesToRead);
_mTotalBytesRead += numBytesRead;
_mNumBytesToRead = (int) Length - _mTotalBytesRead;
_mReadText = byteString.GetString(buffer);
return _mNumBytesToRead;
}
}