How to get Domain Name (pre-Windows 2000) from FQDN (Fully Qualified Domain Name) using C#

This started when I saw a question on stack overflow and it challenged me to solve it. It may look simple initially but least to say it was challenging. The question was about getting a list of all domain names in your network and displaying it in a friendly way like what you see when you log on to Windows rather than yourdepartment.yourdomain.com.

All you have to do is to refer to a COM Reference called Active DS Library which contains the IADsNameTranslate interface which can translate distinguished names (DNs) among various formats.

Now having that tool, it's just a matter of getting a list of domains which I can get in FQDN format easily by Getting the DomainCollection from the Forest you are in. The last issue is converting that FQDN to a DN format which is easy by using String Methods. We are doing this as the reference I mentioned above can only convert from other formats which is defined here and FQDN is not an option so the easiest would be DN. And here is how I did it.

using System.DirectoryServices.ActiveDirectory;
using ActiveDs;

private void ListDomains()
{
 string sUserName = "xxxx";
 string sPassword = "xxxx";

 DirectoryContext oDirectoryContext = 
	new DirectoryContext(DirectoryContextType.Domain, sUserName, sPassword);

 Domain oCurrentDomain = Domain.GetDomain(oDirectoryContext);
 Forest oForest = oCurrentDomain.Forest;
 DomainCollection oAddDomainsInForest = oForest.Domains;

 foreach (Domain oDomain in oAddDomainsInForest)
 {
 Console.WriteLine(GetName(oDomain.ToString()));
 }
}
private string GetName(string sDomainName)
{
 try
 {
 IADsADSystemInfo oSysInfo = new ADSystemInfoClass();
 IADsNameTranslate oNameTranslate = new NameTranslateClass();
 oNameTranslate.Init((int)ADS_NAME_INITTYPE_ENUM.ADS_NAME_INITTYPE_DOMAIN, sDomainName);

 string[] aSplitDN = sDomainName.Split(new Char[] { '.' });
 string sDistinguishedName = "";

 //Convert Domain Name to Distinguished Name
 foreach (string sDomainPart in aSplitDN)
 {
 sDistinguishedName = sDistinguishedName + "DC=" + sDomainPart + ",";
 }

 oNameTranslate.Set((int)ADS_NAME_TYPE_ENUM.ADS_NAME_TYPE_UNKNOWN, 
    sDistinguishedName.Remove(sDistinguishedName.Length - 1));//Remove the last comma
 string sFriendlyName = oNameTranslate.Get((int)ADS_NAME_TYPE_ENUM.ADS_NAME_TYPE_NT4);
 return sFriendlyName.Replace(@"\", "");
 }
 catch
 {
 return "Access Denied";
 }
}

If there's an easy way just let me know, but for now this works for me!