یافتن MAC آدرس کارت شبکه

using System.Management;
 
private void GetMACAddress()
{
    ManagementObjectSearcher searcher;
    string qry = "select * FROM Win32_NetworkAdapter";
    searcher = new ManagementObjectSearcher(qry);
    foreach (ManagementObject wmi_HD in searcher.Get())
        if (wmi_HD["MacAddress"] != null)
            MessageBox.Show(wmi_HD["MacAddress"].ToString());