C#网络编程：通过IP地址获取主机名称

IPHostEntry hostInfo;

            string IP = "";//填入的IP
            string HostName = "";
            try
            {
                hostInfo= Dns.Resolve(IP);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return;
            }
            HostName = hostInfo.HostName;