Check active directory group membership recursively - c#-4.0

Question

So I have a question regarding recursive groups in active directory. I have a little method that checks if a user id is in a group or not. Works great. Found out today that it doesn't check recursive group membership and I'm not too sure how (or if) there is a way to do that. Here's what I have so far for non-recursive:
public static bool CheckGroupMembership(string userID, string groupName, string Domain)
{
bool isMember = false;
PrincipalContext ADDomain = new PrincipalContext(ContextType.Domain, Domain);
UserPrincipal user = UserPrincipal.FindByIdentity(ADDomain, userID);
if (user.IsMemberOf(ADDomain, IdentityType.Name, groupName.Trim()))
{
isMember = true;
}
return isMember;
}
I've seen some things about a directory searcher or something but I'm somewhat new to working directly with AD and while I understand the concepts, some other things are still a little lost on me.
Thanks!

Answer 1

You can also check by using the recursive option of GroupPrincipal.GetMembers.
public static bool CheckGroupMembership(string userID, string groupName, string Domain) {
bool isMember = false;
PrincipalContext ADDomain = new PrincipalContext(ContextType.Domain, Domain);
UserPrincipal user = UserPrincipal.FindByIdentity(ADDomain, userID);
GroupPrincipal group = GroupPrincipal.FindByIdentity(ADDomain, groupName);
if ((user != null) && (group != null)) {
isMember = group.GetMembers(true).Contains(user);
}
return isMember;
}

Answer 2

Here is a solution using System.DirectoryServices.AccountManagement Namespace. It's a kind of recursive solution. In Find Recursive Group Membership (Active Directory) using C#, I give a recursive solution that also works with distribution groups.
/* Retreiving a principal context
*/
Console.WriteLine("Retreiving a principal context");
PrincipalContext domainContext = new PrincipalContext(ContextType.Domain, "WM2008R2ENT:389", "dc=dom,dc=fr", "jpb", "PWD");
/* Look for all the groups a user belongs to
*/
UserPrincipal aUser = UserPrincipal.FindByIdentity(domainContext, "user1");
PrincipalSearchResult<Principal> a = aUser.GetAuthorizationGroups();
foreach (GroupPrincipal gTmp in a)
{
Console.WriteLine(gTmp.Name);
}