// Constructor. public BattleViewModel() { Title = "Battle"; SelectedCharacters = new ObservableCollection <Character>(); AvailableCharacters = new ObservableCollection <Character>(); SelectedMonsters = new ObservableCollection <Monster>(); LoadDataCommand = new Command(async() => await ExecuteLoadDataCommand()); BattleEngine = new BattleEngine(); BattleEngine.BattleEngineClearData(); // Load Data ExecuteLoadDataCommand().GetAwaiter().GetResult(); MessagingCenter.Subscribe <OpeningPage, Character>(this, "AddSelectedCharacter", async(obj, data) => { SelectedListAdd(data); }); MessagingCenter.Subscribe <OpeningPage, Character>(this, "RemoveSelectedCharacter", async(obj, data) => { SelectedListRemove(data); }); }