private async void addSong(Music.Song song) { if (songTable != null) { if (operationMode == OPERATION_MODE.ONLINE) { try { IEnumerable<ParseObject> findSong = await ((ParseQuery<ParseObject>)songTable.findSong(song.Title)).FindAsync(); foreach (ParseObject item in findSong) { if (item.Get<string>(Music.SongTableOnline.COLUMN_TITLE).ToLower().Equals(song.Title.ToLower())) { song.modifyOnline(item); return; } } song.upLoad(); } catch (Exception e) { MessageBox.Show(e.ToString()); } } else if (operationMode == OPERATION_MODE.OFFLINE) { song.saveLocal(LOAD_LOCATION); } } }