Get group members with Azure AD Graph Client Library

When using the latest (2.1.0) version of the Azure AD Graph Client Library, it is not trivial to figure out how to get a group’s members. Even with the code samples there is still some trickery needed. This post shows you how. It assumes you’ve got the authentication part figured out already, of course.

List results = new List();
ActiveDirectoryClient adClient = CreateClient(userId);
IUser user = await adClient.Users.Where(x => x.Mail == model.Email).ExecuteSingleAsync();
if (user != null)
{
    var pagedCollection = await ((IUserFetcher)user).MemberOf.ExecuteAsync();
    do
    {
        results.AddRange(pagedCollection.CurrentPage.OfType().Select(role => role.DisplayName));
        pagedCollection = await pagedCollection.GetNextPageAsync();
    }
    while (pagedCollection != null);
}
return results;

A few comments are in place.

1. The creation of the ActiveDirectoryClient on line 2 is ‘hidden’ in the helper method `CreateClient()`. Not relevant here.
2. We retrieve a matching user by doing comparison on the `Email` field. Change this to anything you like.
3. We use the very convenient `ExecuteSingleAsync()` since we know we only want one, and don’t care about paging results.
4. IMPORTANT we cast the user (on line 6) to an `IUserFetcher`, this enables us to retrieve (paged) results of all group members.
5. On line 9 we use a simple LINQ filter (`OfType()`) to get only users. Group members can be of type groups and principals too, but we don’t care about them.

If you need other samples, take a look at this page on Github, it contains a lot of relevant sample code.