Array subset

[MontgomeryBurns]

Can you describe what you're trying to do in more detail?

Hi!
one of my classes that takes care of socket communication between devices returns an array (byte []) containing a whole message. The message consists of some initial bytes and then a data part. A need to operate to the data part without loss of performances due to Copy stuff (and actually I don't need a copy for any other reason). I represent the message here as follows:

[P] [P] [P] [P] [P] [D] [D] [D] ... [D] [D] [D] [CHK]

[P] bytes are the bytes needed by protocol communication
[D] bytes are the "sub buffer" of data bytes
[CHK] final checksum

The thing is that for every message that arrives I now create a copy of the data bytes to create an array that contains only the [D] bytes.
I need to use the sub buffer for every futher management of the data, after the message arrives. I do not need the [P] bytes anymore, after the message is decoded.

On a Desktop PC machine everything works fine, but when the application is run on a PDA, all of those useless copies consume a lot in matter of RAM and CPU-time, sometimes the PDA goes also into OutOfMemoryException. Consider that my message is usually composed by a few [P] bytes and many [D] bytes. For example a message might be 5000 bytes and only 10 of them are [P] bytes.
That is why I would like to operate onto the original array and not onto a copy of it. I understand now that this may not by possible in C#. Everything would have been much easier in C++ when you could simply use a pointer to a byte in the middle as an array of bytes and pass it as an argument of array of byte.