Retrieving domain users in a Silverlight application using a WCF Service

When you need to get the domain users in a Silverlight application the best option is to go behind a WCF service.Create your WCF service and expose the end points . The proxy created in the Silverlight application can get the details of the domain users using the methods exposed in the WCF.

WCF Class

[ServiceContract]
 public class UserDomain 
 {
     [OperationContract]
     public List<DomainUser> getDomainUsers()
     {
             DirectorySearcher Search = new DirectorySearcher();
             Search.SearchRoot = new DirectoryEntry("LDAP://dc=abc,dc=com");//here abc represents the domain name
             Search.Filter = "(&(objectclass=user)(objectcategory=person))";
             Search.SearchScope = SearchScope.Subtree;
             Search.PropertiesToLoad.Add("userPrincipalName");

             SearchResultCollection colQueryResults = Search.FindAll();
             List<DomainUser> users = new List<DomainUser>();
             foreach (SearchResult Result in colQueryResults)
             {
                 if (Result.Properties["userPrincipalName"] != null)
                 {
                     if (Result.Properties["userPrincipalName"].Count > 0)
                     {
                         users.Add(new DomainUser() { ID = Result.Properties["userPrincipalName"][0].ToString(), 
                             DisplayName = Result.Properties["name"][0].ToString() });
                     }
                 }
             }
             return users;
      }
   }
 [DataContract]
 public class DomainUser
 {
     [DataMember]
     public string ID { get; set; }
     [DataMember]
     public string DisplayName { get; set; }
 }

Silverlight Implementation

Create the Silverlight application and add a service reference to the above created WCF service.Create the client proxy with the added service and call the WCF method to retrieve the domain users.

Code

public partial class MainPage : UserControl
{
    public MainPage()
    {
        try
        {
            InitializeComponent();
            UserDomainClient Proxy = new UserDomainClient();
            Proxy.getDomainUsersCompleted += new EventHandler<getDomainUsersCompletedEventArgs>(Proxy_getDomainUsersCompleted);
            Proxy.getDomainUsersAsync();
        }
        catch (Exception ex)
        {

            MessageBox.Show(ex.Message);
        }
    }

    void Proxy_getDomainUsersCompleted(object sender, getDomainUsersCompletedEventArgs e)
    {
         List<DirectoryServiceExt.DomainUser> lstUsers=e.Result;
    }
}

Make sure that you use basicHttpbinding while deploying the WCF service