How to retrieve Users and Groups seperately from a "Person or Group" column via C# code?

Question

I have a field in the discussion list, which allows the initiator of the discussion to specify the people to share the discussion with.

This field is typed as 'Person or Group' that allows selection of both 'People and Groups'.

How can I retrieve a SPUser collection and a SPGroup collection from this field?

Im on SharePoint 2013.

Answer 1

You need to get the values into a collection object and then iterate through them and test it it is a group, if not assume it is a user, as follows:

SPFieldUserValueCollection objUserFieldValueCol = new SPFieldUserValueCollection(web, listitem["UserGroupField"].ToString());
for (int i = 0; i < objUserFieldValueCol.Count; i++)
{
    SPFieldUserValue singlevalue = objUserFieldValueCol[i];
    if (singlevalue.User == null) // value is a SharePoint group if User is null
    {
        SPGroup group = web.Groups[singlevalue.LookupValue];
        foreach (SPUser user in group.Users)
        {
            //do stuff with the user
        }
    }
    else // singlevalue.User value is a user
    {
        //do stuff for the singlevalue.User
    }
}

I am assuming that you will not have any AD security groups in there, otherwise you will need add some code to handle those.

Answer 2

a shot in the dark here, you can try this that iv just put together?

        using (SPSite site = new SPSite("url goes here"))
        {
            using (SPWeb oWebsite = site.OpenWeb())
            {
                SPList oList = oWebsite.Lists["discussion list name"];
                SPListItem item = oList.GetItemById(12);
                SPUserCollection userCollNew = oWebsite.SiteUsers;;
                SPGroupCollection groupCol = oWebsite.SiteGroups;

                foreach (SPFieldUserValue userValue in item["ColumnName(groups and users)"] as SPFieldUserValue[])
                {
                    //need todo some check here if its a group or user.
                    userCollNew.Add(userValue.User.LoginName, userValue.User.Email, userValue.User.Name, userValue.User.Notes);

                }
                foreach (SPGroup group in item["ColumnName(groups and users)"] as SPGroup[])
                {
                    SPMember omem = oWebsite.Groups[group.Name];
                    groupCol.Add(group.Name, omem, null, group.Description);
                }

            }
        }

lol dont take my world on it, just did it in VS without testing! you can refer to these articles for extra help!

How to get users/usergroups from an lookup column from SPField

http://msdn.microsoft.com/en-gb/library/microsoft.sharepoint.spgroupcollection.add(v=office.15).aspx

http://msdn.microsoft.com/en-gb/library/microsoft.sharepoint.spmember.aspx http://snipplr.com/view/25015/

http://www.c-sharpcorner.com/uploadfile/anavijai/get-the-spfielduservaluecollection-values-using-client-object-model-in-sharepoint-2010/

Answer 3

If there is a possibility of an AD group in there and you would like to handle that, have a look at my solution:

public static List<string> GetUserLogins(SPListItem item)
{
    //create empty list of usernames
    List<string> Users = new List<string>();

    //retrieve user value collection from the "AssignedTo" field and iterate
    SPFieldUserValueCollection usersFields = new SPFieldUserValueCollection(item.Web.Site.RootWeb, item["AssignedTo"].ToString());

    foreach (SPFieldUserValue usersField in usersFields)
    {
        if (usersField.User == null)
        {
            //UserField contains a SharePoint group -> extract users from it
            SPGroup group = item.Web.Groups.GetByID(usersField.LookupId);
            Users.AddRange(from SPUser user in @group.Users select user.LoginName);
        }
        else
        {
            if (usersField.User.IsDomainGroup) 
            {
                //UserField is actually an AD group -> Extract users from AD
                Users = RetrieveADGroupUsers(usersField.User);
            }
            else
            {
                //UserField contains a single SharePoint user
                Users.Add(usersField.User.LoginName);
            }
        }
    }
    return Users.Distinct().ToList();
}

public static List<string> RetrieveADGroupUsers(SPUser user)
{
    List<string> loginNames = new List<string>();
    SPSecurity.RunWithElevatedPrivileges(() =>
    {
        var domainName = Environment.UserDomainName;
        var adDomain = string.Format("LDAP://{0}", domainName);
        var group = user.Name.Split('\\')[1];

        using (var entry = new DirectoryEntry(adDomain))
        {
            using (var dSearch = new DirectorySearcher(entry)
                                 {
                                     Filter = string.Format("(&(objectCategory=group)(cn={0}))", group)
                                 })
            {
                var result = dSearch.FindOne();
                foreach (string member in result.Properties["member"])
                {
                    var de = new DirectoryEntry(string.Concat("LDAP://", domainName, "/", member));
                    if (de.Properties["objectClass"].Contains("user") && de.Properties["samAccountName"].Count > 0)
                    {
                        var samAccName = de.Properties["samAccountName"][0].ToString();
                        loginNames.Add(samAccName);
                    }
                }
            }
        }
    });
    return loginNames;
}