[C#] How to programmatically find a COM port by friendly name

When using the SerialPort.GetPortNames() method, you are querying the current computer for a list of valid serial port names. For example, you can use this method to determine whether “COM1” and “COM2” are valid serial ports in your computer. The port names are obtained from the system registry (if the registry contains stale or otherwise incorrect data then this method will return incorrect data). The limit of this approach is that you get just an array of port names (e.g. { “COM1”,”COM2” … }) and nothing else! If the com ports are physical, there’s no problem but what about virtual ports connected for example through an USB adapter? Well, you can determine if a port is valid but you don’t know exactly which COM number was assigned to your device. So you need more information! In the system Device Manager, you can see the COM port friendly name under the "Ports (COM & LPT)" heading. This means that the right COM port number can be found by using WMI 🙂
A solution to this need comes from WMI Code Creator tool which allows you to generate VBScript, C#, and VB .NET code that uses WMI to complete a management task such as querying for management data, executing a method from a WMI class, or receiving event notifications using WMI.
A suitable WMI query is “SELECT * FROM Win32_PnPEntity WHERE ConfigManagerErrorCode = 0”.
Here is a code example showing how to enumerate the information of the COM ports currently available on your system (including the friendly name of course) by executing the query above.

using System.Management;

internal class ProcessConnection {

   public static ConnectionOptions ProcessConnectionOptions()

   {

     ConnectionOptions options = new ConnectionOptions();

     options.Impersonation = ImpersonationLevel.Impersonate;

     options.Authentication = AuthenticationLevel.Default;

     options.EnablePrivileges = true;

     return options;

   }

 

   public static ManagementScope ConnectionScope(string machineName, ConnectionOptions options, string path)

   {

     ManagementScope connectScope = new ManagementScope();

     connectScope.Path = new ManagementPath(@"\\" + machineName + path);

     connectScope.Options = options;

     connectScope.Connect();

     return connectScope;

   }

}

 

public class COMPortInfo

{

   public string Name { get; set; }

   public string Description { get; set; }

 

   public COMPortInfo() { }     

 

   public static List<COMPortInfo> GetCOMPortsInfo()

   {

     List<COMPortInfo> comPortInfoList = new List<COMPortInfo>();

 

     ConnectionOptions options = ProcessConnection.ProcessConnectionOptions();

     ManagementScope connectionScope = ProcessConnection.ConnectionScope(Environment.MachineName, options, @"\root\CIMV2");

 

     ObjectQuery objectQuery = new ObjectQuery("SELECT * FROM Win32_PnPEntity WHERE ConfigManagerErrorCode = 0");

     ManagementObjectSearcher comPortSearcher = new ManagementObjectSearcher(connectionScope, objectQuery);

 

     using (comPortSearcher)

     {

       string caption = null;

       foreach (ManagementObject obj in comPortSearcher.Get())

       {

         if (obj != null)

         {

           object captionObj = obj["Caption"];

           if (captionObj != null)

           {

              caption = captionObj.ToString();

              if (caption.Contains("(COM"))

              {

                COMPortInfo comPortInfo = new COMPortInfo();

                comPortInfo.Name = caption.Substring(caption.LastIndexOf("(COM")).Replace("(", string.Empty).Replace(")",

                                                     string.Empty);

                comPortInfo.Description = caption;

                comPortInfoList.Add(comPortInfo);

              }

           }

         }

       }

     } 

     return comPortInfoList;

   }
}

Finally you can easily get the com port list in this way…

foreach (COMPortInfo comPort in COMPortInfo.GetCOMPortsInfo())

{

  Console.WriteLine(string.Format("{0} – {1}", comPort.Name, comPort.Description));

}

Other solutions?

• A first alternative is SetupAPI. You can find a complete example here.
• Secondly, you can try to use DevCon (a Microsoft tool that allows "device management" from the command line): you could use the

  System.Diagnostics.Process class to parse the standard output of the command line “>devcon find =ports”.