public MainViewModel() { this.Items = new ObservableCollectionWithItemNotification<ItemViewModel>(); _friends = new ObservableCollection<FriendViewModel>(); GroupedItems = _friends.GroupFriends(); streamUpdater = new Timer(streamUpdater_Tick, null, Timeout.Infinite, Timeout.Infinite); //We do not start the updater here. It will be started by the callback of the reponse //Warning: Possible issue where a internet conenction is not stable loadData(); loadFriends(); }