How can I find out a COM port number of a bluetooth device in c#?

Question

My company developed a device that communicates with a PC via Bluetooth using a virtual COM port.

Now we need a user to pair a device with a PC (MS Windows OS) firs

Answer 1

First, create a Management Object Searcher to search the WMI database:

ManagementObjectSearcher serialSearcher =
                new ManagementObjectSearcher("root\\CIMV2",
                "SELECT * FROM Win32_SerialPort");

Next, use LINQ to get all the serial ports into a query:

var query = from ManagementObject s in serialSearcher.Get()
            select new { Name = s["Name"], DeviceID = s["DeviceID"], PNPDeviceID = s["PNPDeviceID"] }; // DeviceID -- > PNPDeviceID

You can now print all the COM ports, their friendly names and you can even filter through their PNPDeviceID's to find the bluetooth device address. Here's an example:

foreach (var port in query)
{
    Console.WriteLine("{0} - {1}", port.DeviceID, port.Name);
    var pnpDeviceId = port.PNPDeviceID.ToString();

    if(pnpDeviceId.Contains("BTHENUM"))
    {
        var bluetoothDeviceAddress = pnpDeviceId.Split('&')[4].Split('_')[0];
        if (bluetoothDeviceAddress.Length == 12 && bluetoothDeviceAddress != "000000000000")
        {
            Console.WriteLine(" - Address: {0}", bluetoothDeviceAddress);
        }
    }
}