读取本机所有com端口

 RegistryKey keyCom = Registry.LocalMachine.OpenSubKey("Hardware\\DeviceMap\\SerialComm");
            if (keyCom != null)
            {
                string[] sSubKeys = keyCom.GetValueNames();
                this.cbbPort.Items.Clear();
                foreach (string sName in sSubKeys)
                {
                    string sValue = (string)keyCom.GetValue(sName);
                    this.cbbPort.Items.Add(sValue);
                }
            }