Solved

Parallel Port access with C#

Posted on 2004-05-01
6
437 Views
Last Modified: 2012-06-27
I'm looking for some help on writing to the parallel port within WinXP Pro using C#.  I'm not sure how this is done and I can't find any substantial resources online.  All I want to do is be able to write a byte, that's it, nothing else.

Thanks
0
Comment
Question by:ChaveTech
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 5

Expert Comment

by:jjacksn
ID: 10969965
This should do it:

http://www.codeproject.com/csharp/csppleds.asp?df=100&forumid=21021&exp=0&select=799135

In addition, you could always write it in a C++ com and interop to it.
0
 

Author Comment

by:ChaveTech
ID: 10970057
I've been to that site and have tried it, but it's not working.  I don't know if the DLL the author provides is valid.  I don't have a problem writing it in C++, but I'm not familiar with writing in COM.  Do you have any suggestions?
0
 
LVL 9

Expert Comment

by:glsac
ID: 10970199
0
Online Training Solution

Drastically shorten your training time with WalkMe's advanced online training solution that Guides your trainees to action. Forget about retraining and skyrocket knowledge retention rates.

 
LVL 5

Expert Comment

by:jjacksn
ID: 10970873
ChaveTech,

With com, all you need to do is create an ATL com object.  Use the template.  Add a method called to the COM interface you create called WriteParallelByte which takes in a byte (as an int).  You can then simply include this in a C# project by adding a reference to the COM object (dll).  .NET Studio will then automatically create an interop dll that will allow you to instantiate this com object and make the call.
0
 
LVL 4

Accepted Solution

by:
philippe_leybaert earned 500 total points
ID: 11003906
If you just want to write some bytes or text to the parallel port, you can create an output file stream that maps to the parallel port:

The drawback is that you need to call unmanaged code from kernel32.dll

class myClass
{            
   [DllImport("kernel32.dll", CharSet=CharSet.Unicode)]
   private static extern IntPtr CreateFile(
                    string lpFileName,
                    [MarshalAs(UnmanagedType.U4)] uint dwDesiredAccess,
                    [MarshalAs(UnmanagedType.U4)] int dwShareMode,
                    [MarshalAs(UnmanagedType.U4)] uint lpSecurityAttributes,
                    [MarshalAs(UnmanagedType.U4)] int dwCreationAttributes,
                    [MarshalAs(UnmanagedType.U4)] int dwFlagsAndAttributes,
                    IntPtr hTemplateFile
                   );

   public FileStream createLPT1_FS()
   {
      IntPtr h = CreateFile("LPT1",0xC0000000,0,0,3,0,(IntPtr)0);

      return new FileStream(h,FileAccess.ReadWrite);
   }
}
0
 
LVL 5

Expert Comment

by:jjacksn
ID: 11006866
Windows knows how to Map files like this?  I had no idea....
0

Featured Post

Salesforce Made Easy to Use

On-screen guidance at the moment of need enables you & your employees to focus on the core, you can now boost your adoption rates swiftly and simply with one easy tool.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: Ivo
C# And Nullable Types Since 2.0 C# has Nullable(T) Generic Structure. The idea behind is to allow value type objects to have null values just like reference types have. This concerns scenarios where not all data sources have values (like a databa…
This article describes a simple method to resize a control at runtime.  It includes ready-to-use source code and a complete sample demonstration application.  We'll also talk about C# Extension Methods. Introduction In one of my applications…
In a recent question (https://www.experts-exchange.com/questions/29004105/Run-AutoHotkey-script-directly-from-Notepad.html) here at Experts Exchange, a member asked how to run an AutoHotkey script (.AHK) directly from Notepad++ (aka NPP). This video…

730 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question