Public Shared Function GetUserMemberOf(ByVal domain As String, ByVal username As String, ByVal password As String, Optional ByRef exeption As Exception = Nothing) As Collections.Generic.List(Of String) 
Dim searcher As DirectorySearcher = Nothing
Dim colEntry As New Collections.Generic.List(Of String) 
Try

'Objet de notre utilisateur de la hiérarchie Active Directory.
searcher = New DirectorySearcher(New DirectoryEntry("LDAP://" & domain, username, password)) 
'On va chercher ici un objet de type user et dont le nom d'ouverture de session = <username>.
searcher.Filter = String.Concat("(&(objectClass=User) (sAMAccountName=", username, "))") 
'Ne récupère que la propriété MemberOf.
searcher.PropertiesToLoad.Add("MemberOf") 
'Recherche et retourne la première entrée trouvée.
Dim result As SearchResult = searcher.FindOne 
'Parcours le contenu de la propriété MemberOf de notre entrée trouvée.
For i As Integer = 0 To result.Properties("MemberOf").Count - 1 
'Récupère la chaine LDAP.
Dim sProp As String = result.Properties("MemberOf")(i) 
'Extrait le nom du groupe de la chaine.
colEntry.Add(sProp.Substring(3, sProp.IndexOf(",") - 3)) 
Next
Catch ex As Exception 
exeption = ex

Finally

'Libère les ressources.

searcher.Dispose()

End Try
Return colEntry 
End Function

public static List<String> GetUserMemberOf(string domain, string username, string password) 
{
DirectorySearcher searcher = null; 
List<string> lMembers = new List<string>();
try


{
searcher = new DirectorySearcher(new DirectoryEntry(string.Concat(@"LDAP://", domain), username, password)); 
searcher.Filter = string.Concat(@"(&(objectClass=User) (sAMAccountName=", username, "))");searcher.PropertiesToLoad.Add(
@"MemberOf"); 
SearchResult result = searcher.FindOne();
for (int i = 0; i < result.Properties[@"MemberOf"].Count; i++) 
{
string szProp = result.Properties[@"MemberOf"][i].ToString();lMembers.Add(szProp.Substring(3, szProp.IndexOf(@",") - 3)); 
}

}
catch (Exception) 
{
throw; 
}

finally

{

searcher.Dispose();

}

return lMembers;