Get subnet mask from network key stored in Registry : Registry Network « Windows « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Windows
3. Registry Network

using System;
using Microsoft.Win32;

class MainClass
{
    public static void Main()
    {
      RegistryKey start = Registry.LocalMachine;
      RegistryKey cardServiceName, networkKey;
      string networkcardKey = "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\NetworkCards";
      string serviceKey = "SYSTEM\\CurrentControlSet\\Services\\";
      string networkcardKeyName, deviceName, deviceServiceName, serviceName;
    
      RegistryKey serviceNames = start.OpenSubKey(networkcardKey);
      if (serviceNames == null)
      {
          Console.WriteLine("Bad registry key");
          return;
      }
    
      string[] networkCards = serviceNames.GetSubKeyNames();
      serviceNames.Close();
    
      foreach(string keyName in networkCards)
      {
          networkcardKeyName = networkcardKey + "\\" + keyName;
          cardServiceName = start.OpenSubKey(networkcardKeyName);
          if (cardServiceName == null)
          {
            Console.WriteLine("Bad registry key: {0}", networkcardKeyName);
            return;
          }
          deviceServiceName = (string)cardServiceName.GetValue("ServiceName");
          deviceName = (string)cardServiceName.GetValue("Description");

          serviceName = serviceKey + deviceServiceName + "\\Parameters\\Tcpip";
          networkKey = start.OpenSubKey(serviceName);
          if (networkKey == null)
          {
            Console.WriteLine("    No IP configuration set");
            return;
          }
          string[] subnetmasks = (string[])networkKey.GetValue("SubnetMask");

          foreach(string subnetmask in subnetmasks)
          {
              Console.WriteLine("    Subnet Mask: {0}", subnetmask);
          }
          networkKey.Close();
      }
      start.Close();
    }
}

Subnet Mask: 0.0.0.0
    Subnet Mask: 0.0.0.0