private void AddFeed(object obj) { var f = new FeedViewModel(new FeedModel("about:blank")); var dialog = new AddFeedDialog(f); bool?res = dialog.ShowDialog(); if (!((res == null) || !res.Value)) { if (!string.IsNullOrEmpty(f.Link)) { FeedsList.Add(f); _model.AddFeed(f.GetModel()); } } }