Question

The below code works on my local machine by returning the user’s full name from Active Directory:

string principal = System.Web.HttpContext.Current.Request.LogonUserIdentity.Name.Remove(0, 12);

string filter = string.Format("(&(ObjectClass={0})(sAMAccountName={1}))", "person", principal);

string[] properties = new string[] { "fullname" };

DirectoryEntry adRoot = new DirectoryEntry("LDAP://myserver.com");
adRoot.AuthenticationType = AuthenticationTypes.Secure;

DirectorySearcher searcher = new DirectorySearcher(adRoot);

searcher.SearchScope = SearchScope.Subtree;

searcher.ReferralChasing = ReferralChasingOption.All;

searcher.PropertiesToLoad.AddRange(properties);

searcher.Filter = filter;

SearchResult result = searcher.FindOne();

DirectoryEntry directoryEntry = result.GetDirectoryEntry();

string displayName = directoryEntry.Properties["displayName"][0].ToString();

if (string.IsNullOrEmpty(displayName) == false)
{
    return displayName;
}

When I publish it to the development server I get the following error:

System.NullReferenceException: Object reference not set to an instance
of an object.

The error is thrown on the following line:

DirectoryEntry directoryEntry = result.GetDirectoryEntry();

I have tried

DirectoryEntry adRoot = new DirectoryEntry("LDAP://" + domain, AdAdminUsername, AdAdminPassword, AuthenticationTypes.Secure);

but still no joy.

Any ideas?

Thanks!

Answer 1

Just from outside : your string called principal is built by the following :

string principal = System.Web.HttpContext.Current.Request.LogonUserIdentity.Name.Remove(0, 12);

Have you log 'System.Web.HttpContext.Current.Request.LogonUserIdentity.Name‘ on your dev server ? This static construction may be the begining of you troubles because if principal is’nt what you think it is, the result of FindOne may be NULL.