/// <summary>
        /// Loads friends avatars from the web and updates it in UI.
        /// </summary>
        public void LoadAvatars()
        {
            try
            {
                var itemsToLoad = _GetInitialAvatarsToLoad();

                if (!itemsToLoad.Any())
                    _isInited = true; // Only if no one item loaded we may think that nothing was initialized - this is first time.
                else
                {
                    var service = new AsyncAvatarsLoader();
                    service.LoadAvatars(itemsToLoad, _UpdateAvatar, () =>
                    {
                        var dialogsToReloadPicture = Dialogs.Where(d => d.IsConference);

                        Deployment.Current.Dispatcher.BeginInvoke(() =>
                        {
                            try
                            {
                                foreach (var dialog in dialogsToReloadPicture)
                                {
                                    var key = _GenereateGroupChatAvatar(dialog);

                                    if (key == string.Empty)
                                    {
                                        dialog.Photo = DefaultAvatar;
                                    }
                                    else
                                    {
                                        var image = _imageCache.GetItem(key);

                                        if (image != null)
                                            dialog.Photo = image;
                                    }
                                }
                            }
                            catch (Exception ex)
                            {
                                Debug.WriteLine("LoadAvatars failed in EntityService: " + ex.Message);
                            }

                            _isInited = true;
                        });
                    });
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine("LoadAvatars failed " + ex.Message);
            }
        }
        private void _LoadPhotos()
        {
            try
            {
                var service = new AsyncAvatarsLoader();

                // From map of attachment view model and load items get collection of avatar load items...
                var photosToLoad = _photosToLoad.Select(x => x.Value);

                if (photosToLoad.Any())
                    service.LoadAvatars(photosToLoad.ToList(), _UpdatePhoto, null);
            }
            catch (Exception ex)
            {
                Debug.WriteLine("LoadPhotos failed " + ex.Message);
            }
        }
        private bool _AddLocationAttachment()
        {
            if (!string.IsNullOrEmpty(App.Current.EntityService.AttachedLatitude) &&
                !string.IsNullOrEmpty(App.Current.EntityService.AttachedLongitude))
            {
                try
                {
                    string uri = String.Format(AppResources.GeolocationMapUriFormatMessage,
                        App.Current.EntityService.AttachedLatitude.Replace(",", "."),
                        App.Current.EntityService.AttachedLongitude.Replace(",", "."));

                    var avm = new AttachmentViewModel(-1, -1, -1, AttachmentType.Location, uri, null, null, null, null);
                    _model.Add(avm);

                    string filename = CommonHelper.DoDigest(uri);
                    var photosToLoad = new List<AvatarLoadItem>();
                    photosToLoad.Add(new AvatarLoadItem(1, uri, filename));

                    var service = new AsyncAvatarsLoader();

                    if (photosToLoad.Any())
                        service.LoadAvatars(photosToLoad.ToList(), id =>
                        {
                            Deployment.Current.Dispatcher.BeginInvoke(() =>
                            {
                                try
                                {
                                    ImageCache cache = new ImageCache();
                                    BitmapImage image = cache.GetItem(filename);

                                    if (image != null && image.PixelHeight > 0 && image.PixelWidth > 0)
                                    {
                                        avm.AttachPhoto = image;
                                    }
                                }
                                catch (Exception ex)
                                {
                                    Debug.WriteLine("_AddLocationAttachment failed in AttachmentsPage: " + ex.Message);
                                }
                            });
                        }, null);
                }
                catch (Exception ex)
                {
                    Debug.WriteLine("Load attached location photo failed " + ex.Message);
                }

                return true;
            }

            return false;
        }