判断串口号是否存在 通过访问注册表

    /// <summary>
    /// 判断串口号是否存在
    /// </summary>
    /// <param name="portName"></param>
    /// <returns></returns>
    private bool IsComExits(string portName)
    {
        //这个方法是有BUG的
        //SerialPort.GetPortNames().Contains(portName);
        List<string> result = new List<string>();
        try
        {
            //搜索设备管理器中的所有条目
            using (ManagementObjectSearcher searcher = new ManagementObjectSearcher("select * from Win32_PnPEntity"))
            {
                var hardInfos = searcher.Get();
                foreach (var hardInfo in hardInfos)
                {
                    if (hardInfo.Properties["Name"].Value != null)
                    {
                        string name = hardInfo.Properties["Name"].Value.ToString();
                        if (name.Contains("(COM") && name.EndsWith(")"))
                        {
                            if (name.Contains("->"))
                            {
                                result.Add(name.Substring(name.IndexOf('(') + 1, name.IndexOf(')') - name.IndexOf('-') - 2));
                            }
                            else
                            {
                                result.Add(name.Substring(name.IndexOf('(') + 1, name.IndexOf(')') - name.IndexOf('(') - 1));
                            }
                        }
                    }
                }
                searcher.Dispose();
            }
        }
        catch
        {
            result = new List<string>();
        }
        return result.Contains(portName);
    }