学步园

 public IPAddressCollection GetDnsAddresses()
         {
             NetworkInterface[] adapters = NetworkInterface.GetAllNetworkInterfaces();
             foreach (NetworkInterface adapter in adapters)
             {

                 IPInterfaceProperties adapterProperties = adapter.GetIPProperties();
                 return adapterProperties.DnsAddresses;
             }
             return null;
         }
         public string getDnsIpv4()
         {
             foreach (var item in GetDnsAddresses())
             {
                 if (item.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
                 {
                   return item.ToString();
                     break;
                 }
             }
             return null;
         }

调用：
  //this.Text = getDnsIpv4();