How to Retrieve "Network Interfaces" in C#

Environment: C# .NET

The following code is used to retrieve the "network interfaces" in C#. You may recognize the "network interfaces" as "Network and Dial-up Connections": You can access them by using "Start > Setting > Network and Dial-up Connections". C# does not provide a simple way of retrieving this list. The solution includes two main steps, which follow:

Step 1: Retrieve the Network Adapters

Get all the Network Adapters, which are IP-enabled, and their Setting ID. We use the ManagementClass: Win32_NetworkAdapterConfiguration to achieve this. The "SettingID" property of the ManagementObject is actually the Registry key.

Step 2: Extract information from the Registry

According the "SettingID", extract the following value from the Registry:

   HKEY_LOCAL_MACHINE\
      SYSTEM\CurrentControlSet\control\Network\{xxxxxx}\
             <SettingID>\connection

Where {xxxxxx} is an unknown value, there for we go over all the keys under SYSTEM\CurrentControlSet\control\Network\ and <SettingID> is the values we found in Step 1.

using Microsoft.Win32;
using System.Management;

// holds the network interfaces names (such as "Local Area
// Connection")
private string[] networkInterfaces = new string[MAX_CONNECTIONS];

// holds the network interface Registry key (which is the SettingID
// of the adapter, such as: B76D5407-4610-499A-A8A5-50AAD2A2297E)
private string[] networkInterfacesSettingId =
                 new string[MAX_CONNECTIONS];

// holds the number of network interfaces found
private int numberOfNetworkInterfaces = 0;

// extract all the IP-enabled adapters and get their SettingID
// (which is the Registry key)
ManagementClass objMC = new ManagementClass(
                        "Win32_NetworkAdapterConfiguration");
ManagementObjectCollection objMOC = objMC.GetInstances();

foreach(ManagementObject objMO in objMOC)
{
   if( Convert.ToBoolean(objMO["ipEnabled"]) == false )
      continue;

   string SettingID = "";
   try
   {
      networkInterfacesSettingId[numberOfNetworkInterfaces] =
          (string)objMO["SettingID"];
      ++numberOfNetworkInterfaces;
   }
   catch{}
}

if(numberOfNetworkInterfaces == 0)
{
   MessageBox.Show("No Network Interface were found on this local
                    machine", "Error", MessageBoxButtons.OK,
                    MessageBoxIcon.Error);
   return;
}

int j=0;

// The network interfaces are in the following path in the Registry:
// HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\control\
//      Network\{xxxxxx}\SettingID\connection

RegistryKey networkRegistry = currentMachineRegistry.OpenSubKey(
            "SYSTEM\\CurrentControlSet\\control\\Network");
int num = networkRegistry.SubKeyCount;
string[] tmp = networkRegistry.GetSubKeyNames();
for(int i=0; i<num; ++i)
{
   // get all the {xxxxxx} keys under 'Network'
   RegistryKey conReg = networkRegistry.OpenSubKey(tmp[i]);
   if(conReg != null)
   {
      string[] tmp1 = conReg.GetSubKeyNames();
      if(tmp1.Length > 0)
      {
         for(int k=0; k<tmp1.Length; ++k)
         {
            // get all the <SettingID> keys under 'Network\{xxxxxx}'
            RegistryKey reg = conReg.OpenSubKey(tmp1[k]);
            if(reg != null)
            {
               int gg = Array.BinarySearch(
                        networkInterfacesSettingId, 0, 
                        numberOfNetworkInterfaces, tmp1[k]);
               if(gg >= 0)
               {
                  // This subkey was found in the
                  // networkInterfacesSettingId array - which means
                  // that this is a valid network interface -
                  // let's get the interface name
                  // get the 'connection' key under
                  // 'Network\{xxxxxx}\<SettingID>'
                  RegistryKey r = reg.OpenSubKey("connection");
                  if(r != null)
                  {
                     Object obj = r.GetValue("Name");
                     networkInterfaces[gg] = obj.ToString();
                  }
               }
            }
         }
      }
   }
}

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