How to access device like PRN, LPT1, COM1

[IAmWind]

i need to access these devices, but i cann't get
information from .net framework document.
i use FileStream("PRN", FileMode.Create,
FileAccess.Write);. when it runs, system reported
exception.

 

[Chris Tacke, eMVP]

You must P/Invoke CreateFile, WriteFile, ReadFile, etc.

http://www.opennetcf.org/Forums/topic.asp?TOPIC_ID=83

 

[Dick Grier]

Hi,

What is it that you really want to do? The procedures required will vary.
As Chris says, you can P/Invoke the underlying APIs. This works for serial
ports, as does using various ActiveX add-ons, or other serial objects.
However, depending on what you want to do with the printer port you may not
need (or be able to) use Windows APIs.

Dick

--
Richard Grier (Microsoft Visual Basic MVP)

See www.hardandsoftware.net for contact information.

Author of Visual Basic Programmer's Guide to Serial Communications, 3rd
Edition ISBN 1-890422-27-4 (391 pages) published February 2002.

 

[David Browne]

You must P/Invoke CreateFile, WriteFile, ReadFile, etc.

http://www.opennetcf.org/Forums/topic.asp?TOPIC_ID=83

--

One more thing.

The handle returned from CreateFile can be passed to the FileStream
constructor.

So CreateFile may be the only API you need. Once you have a handle, just
create a new FileStream around it and use the FileStream to read and write.


David

 

[IAmWind]

i cann't understand your words completely.
but i will study for it.
i wrote a DLL to wrap that operation, then P/Invoke in C#.
thanks again.