Enumerating a List of systems Com Ports in Delphi

Question

Objective: I would like to be able to list the available COM Ports on a system in Delphi.

Homework: I have read this SO thread on enumerating the LPT ports of a system using the registry. I have also found that the COM ports are listed in the registry at HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\SERIALCOMM but found unanswered gesticulation in the same thread that this might not be reliable on different machines and different versions of windows.

I also found articles referencing the use of QueryDosDevice() but upon trying this sample code, I found that it did not appear to list any COM ports at all.

Question: What is the most reliable way (across unknown Windows Versions) to list the COM ports on a Windows Machine?

Sedat Kapanoglu · Accepted Answer · 2009-03-05T18:57:46.547

1

DEVICEMAP\SERIALCOMM is good for all NT versions. You'll probably need to look under DYN_DATA for Win9x.

Use this method if you need runtime reliability.

edited Mar 05 '09 at 18:57

answered Mar 05 '09 at 01:14

Sedat Kapanoglu

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This looks to be the best way but if I'm reading the documentation correctly it is created on start-up. Does that mean that Serial Devices added after boot up will not be present? – jamiei Mar 05 '09 at 18:37
Probably not. But as the device actually uses a USB to Serial Bridge it may confuse a few people who are used to plugging in USB devices after boot. – jamiei Mar 05 '09 at 18:57
I added an alternative way of doing it which can handle runtime. – Sedat Kapanoglu Mar 05 '09 at 18:58
The Same as posted @lakshmanaraj below. I'm guessing that someone must have translated this for Delphi use before? – jamiei Mar 05 '09 at 19:21
It's pure Win32 API you should be able to write it in Delphi in an hour. – Sedat Kapanoglu Mar 05 '09 at 23:17
1

I had a lot of trouble getting the codeproject.com sample working with Cygwin (ANSI C), and ended up creating a simple function based on `GetDefaultCommConfig()`. See http://stackoverflow.com/questions/1205383/listing-serial-com-ports-on-windows/3018813#3018813 – tomlogic Jun 10 '10 at 21:54

score 1 · Answer 2 · answered Mar 05 '09 at 12:18

1

Please go through URL which is written in C++

http://www.codeproject.com/KB/system/serial_portsenum_fifo.aspx

and same approach can be implemented in delphi too.. or somebody can convert for you in SO..

This will work for all windows versions since this works from the principle of device manager which is available for all window versions.

answered Mar 05 '09 at 12:18

lakshmanaraj

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Simpler method (in C) in my answer to another SO question: http://stackoverflow.com/questions/1205383/listing-serial-com-ports-on-windows/3018813#3018813 – tomlogic Jun 10 '10 at 21:55

score 0 · Answer 3 · edited Apr 19 '13 at 12:54

0

This is code for LINUX not for WINDOWS....

function GetSerialPortNames: string;
var
  Index: Integer;
  Data: string;
  TmpPorts: String;
  sr : TSearchRec;
begin
  try
    TmpPorts := '';
    if FindFirst('/dev/ttyS*', $FFFFFFFF, sr) = 0 then
    begin
      repeat
        if (sr.Attr and $FFFFFFFF) = Sr.Attr then
        begin
          data := sr.Name;
          index := length(data);
          while (index > 1) and (data[index] <> '/') do
            index := index - 1;
          TmpPorts := TmpPorts + ' ' + copy(data, 1, index + 1);
        end;
      until FindNext(sr) <> 0;
    end;
    FindClose(sr);
  finally
    Result:=TmpPorts;
  end;
end;

edited Apr 19 '13 at 12:54

Warren P

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answered Mar 05 '09 at 11:50

SimaWB

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Thanks but this gave me an empty string on the target machine. – jamiei Mar 05 '09 at 18:36
You know you can EDIT your answers and FIX them so they aren't WRONG, right? Or delete them to save people from figuring out that they are wrong by trying them out. – Warren P Apr 19 '13 at 12:55

Enumerating a List of systems Com Ports in Delphi

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