detect_usb_serial.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Management;

namespace SuperPuperNamespace
{
    static partial class Program
    {
        static List<USBDeviceInfo> GetUSBDevices()
        {
            List<USBDeviceInfo> devices = new List<USBDeviceInfo>();

            ManagementObjectCollection collection;
            using (var searcher = new ManagementObjectSearcher(@"Select * From Win32_PnPEntity "))
                collection = searcher.Get();

            foreach (var device in collection)
            {
                devices.Add(new USBDeviceInfo(
                                (string)device.GetPropertyValue("DeviceID"),
                                (string)device.GetPropertyValue("PNPDeviceID"),
                                (string)device.GetPropertyValue("Description"),
                                (string)device.GetPropertyValue("Name")
                           ));
            }

            collection.Dispose();
            return devices;
        }

		// Выдаёт первый попавшийся usb-com с нужным вид-пидом
        static string GetSerialByUSB()
        {
            var usb = GetUSBDevices();

            foreach(var U in usb)
            {
				// Вид-пид проверяем
                if(U.CheckVidPid(0x1234, 0x5678))
                {
                    string Name = U.Name;

                    int Start = Name.IndexOf('(');
                    int End = Name.IndexOf(')');

                    return Name.Substring(Start + 1, End - Start - 1);
                }
            }

            return null;
        }
    }

    class USBDeviceInfo
    {
        public USBDeviceInfo(string deviceID, string pnpDeviceID, string description, string Name)
        {
            this.DeviceID = deviceID;
            this.PnpDeviceID = pnpDeviceID;
            this.Description = description;
            this.Name = Name;
        }
        public string DeviceID { get; private set; }
        public string PnpDeviceID { get; private set; }
        public string Description { get; private set; }
        public string Name { get; private set; }

        public bool CheckVidPid(int Vid, int Pid)
        {
            var VidS = String.Format("VID_{0:X4}", Vid);
            var PidS = String.Format("PID_{0:X4}", Pid);

            return DeviceID.Contains(VidS) && DeviceID.Contains(PidS);
        }
    }
}