How do I find a user's Active Directory display name in a C# web application?

I'm writing a web application which uses windows authentication and I can happily get the user's login name using something like:

 string login = User.Identity.Name.ToString();

But I don't need their login name I want their DisplayName. I've been banging my head for a couple hours now...

Can I access my organisation's AD via a web application?

From stackoverflow

• See related question: Active Directory: Retrieve User information

  See also: Howto: (Almost) Everything In Active Directory via C# and more specifically section "Enumerate an object's properties".

  If you have a path to connect to a group in a domain, the following snippet may be helpful:

  GetUserProperty("<myaccount>", "DisplayName");
  
  public static string GetUserProperty(string accountName, string propertyName)
  {
   DirectoryEntry entry = new DirectoryEntry();
   // "LDAP://CN=<group name>, CN =<Users>, DC=<domain component>, DC=<domain component>,..."
   entry.Path = "LDAP://...";
   entry.AuthenticationType = AuthenticationTypes.Secure;
  
   DirectorySearcher search = new DirectorySearcher(entry);
   search.Filter = "(SAMAccountName=" + accountName + ")";
   search.PropertiesToLoad.Add(propertyName);
  
   SearchResultCollection results = search.FindAll();
   if (results != null && results.Count > 0)
   {
    return results[0].Properties[propertyName][0].ToString();
   }
   else
   {
           return "Unknown User";
   }
  }
  

• How about this:

  private static string GetFullName()
      {
          try
          {
              DirectoryEntry de = new DirectoryEntry("WinNT://" + Environment.UserDomainName + "/" + Environment.UserName);
              return de.Properties["fullName"].Value.ToString();
          }
          catch { return null; }
      }
  

  thismat : This is the best way to do it for single user propreties.

  DrG : Yeah, I'm liking the simplicity of this ALOT, especially since it works. I owe you a drink!

  DrG : This did work, but the WINNT:// properties are a lot less comprehesive than the LDAP:// properties (see http://www.rlmueller.net/Name_Attributes.htm) so while this did work, I was unable to get say user's email addresses using the WINNT:// binding

• There is a CodePlex project for Linq to AD, if you're interested.

  It's also covered in the book LINQ Unleashed for C# by Paul Kimmel - he uses the above project as his starting point.

  not affiliated with either source - I just read the book recently

• In case anyone cares I managed to crack this one:

        /// This is some imaginary code to show you how to use it
  
        Session["USER"] = User.Identity.Name.ToString();
        Session["LOGIN"] = RemoveDomainPrefix(User.Identity.Name.ToString()); // not a real function :D
        string ldappath = "LDAP://your_ldap_path";
        // "LDAP://CN=<group name>, CN =<Users>, DC=<domain component>, DC=<domain component>,..."
  
  
        Session["cn"] = GetAttribute(ldappath, (string)Session["LOGIN"], "cn");
        Session["displayName"] = GetAttribute(ldappath, (string)Session["LOGIN"], "displayName");
        Session["mail"] = GetAttribute(ldappath, (string)Session["LOGIN"], "mail");
        Session["givenName"] = GetAttribute(ldappath, (string)Session["LOGIN"], "givenName");
        Session["sn"] = GetAttribute(ldappath, (string)Session["LOGIN"], "sn");
  
  
  /// working code
  
  public static string GetAttribute(string ldappath, string sAMAccountName, string attribute)
      {
          string OUT = string.Empty;
  
          try
          {
              DirectoryEntry de = new DirectoryEntry(ldappath);
              DirectorySearcher ds = new DirectorySearcher(de);
              ds.Filter = "(&(objectClass=user)(objectCategory=person)(sAMAccountName=" + sAMAccountName + "))";
  
              SearchResultCollection results = ds.FindAll();
  
              foreach (SearchResult result in results)
              {
                  OUT =  GetProperty(result, attribute);
              }
          }
          catch (Exception t)
          {
              // System.Diagnostics.Debug.WriteLine(t.Message);
          }
  
          return (OUT != null) ? OUT : string.Empty;
      }
  
  public static string GetProperty(SearchResult searchResult, string PropertyName)
      {
          if (searchResult.Properties.Contains(PropertyName))
          {
              return searchResult.Properties[PropertyName][0].ToString();
          }
          else
          {
              return string.Empty;
          }
      }
  

  DrG : typo fixed :D!!

• FYI, there's a typo in the above code...

      SearchResultCollection results = ds.FindAll();
      foreach (SearchResult result in ds.FindAll())
      {
          OUT =  GetProperty(result, attribute);
      }
  

  should read:

      SearchResultCollection results = ds.FindAll();
      foreach (SearchResult result in **results**)
      {
          OUT =  GetProperty(result, attribute);
      }
  

  Hope that helps :-)