testing for missing attributes on an AD search

I'm doing an active directory search (code below).  Some of the attributes I'm searching for don't exist on some of the people.  I'm trying to test for the values which may not be there before I access them and generate an error.  I found some code below to test for the existence of the values but it doesn't work.  I know I can always use Try & Catch but I'd rather have a method that can actually test than catch errors.

       DirectorySearcher search = new DirectorySearcher(entry);
       search.Filter = "(&(objectClass=user) (mail=" + account + "))";
// I'm adding in the fields that I want returned in my search

      SearchResult result = search.FindOne();

      if (result != null)
// I was expecting the next two lines to tell me if the mail element exists
          Type t = result.GetType();
// p=null even though the mail element does exist
          PropertyInfo p = t.GetProperty("mail");
//mail contains the correct value even though p was null in the line above
          string mail=result.Properties["mail"][0].ToString();
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Carl TawnSystems and Integration DeveloperCommented:
p is null because "mail" isn't actually a property of the object, its purely a piece of metadata exposed through what is basically a HashTable.

So you can test for the existence of a element using the Contains() method:
if (result != null)
     string mail;

     if (result.Properties.Contains("mail"))
         mail = result.Properties["mail"][0];

Open in new window


Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
dr761Author Commented:
Works great!  Thanks!
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
.NET Programming

From novice to tech pro — start learning today.