Question

我有一个多页MVVM应用程序，它有一些ViewModel。（这是一个爱好应用程序，存储统计数据和东西）

以下课程

GamePageViewModel
MenuViewModel
PlayersViewModel
StartPagePresenter
Controller（这充当PageSwitcher以及存储数据库中所有TableAdapters的模型）

所有这些都有一些相同的变量

Universe
Character
Season

我想要做的是将这些变量移动到我的MainMenuViewModel（所有页面上的菜单栏），在这里您可以选择Universe，Character，Season等，然后填充到另一个的ViewModels。

我的MenuViewModel班级

    public class MenuViewModel : ObservableObject
    {

        private DataView _Universes = Controller.UniverseTableAdapter.GetData().DefaultView;
        private DataRowView _SelectedUniverse;

        public DataView Universes
        {
            get { return _Universes; }
            set
            {
                _Universes = value;
                RaisePropertyChangedEvent("Universes");
            }
        }

        public DataRowView SelectedUniverse
        {
            get { return _SelectedUniverse; }
            set
            {
                _SelectedUniverse = value;
                Controller.SelectedUniverse = _SelectedUniverse;
                RaisePropertyChangedEvent("SelectedUniverse");
            }
        }

        public ICommand GoHome { get { return new DelegateCommand(NavigateHome); } }

        public ICommand GoPlayers { get { return new DelegateCommand(NavigatePlayers); } }

        public ICommand GoGame { get { return new DelegateCommand(NavigateGame); } }


        public void NavigateHome() { Controller.Switch(new StartPage()); }

        public void NavigatePlayers() { Controller.Switch(new PlayerPage()); }

        public void NavigateGame() { Controller.Switch(new GamePage()); }

    }

我以为我会尝试将它们存储在这样的Controller类中，但不确定如何将RaisePropertyChangedEvent事件发送到每个ViewModel

    public static class Controller
    {

        #region Variables

        //Variables
        private static MainWindow _Window;

        private static MaddenDBDataSet _MaddenDB = new MaddenDBDataSet();
        private static CharacterTableAdapter _CharacterTableAdapter = new CharacterTableAdapter();
        private static FranchiseTableAdapter _FranchiseTableAdapter = new FranchiseTableAdapter();
        private static GamePlayerTableAdapter _GamePlayerTableAdatper = new GamePlayerTableAdapter();
        private static GameTableAdapter _GameTableAdapter = new GameTableAdapter();
        private static PersonTableAdapter _PersonTableAdapter = new PersonTableAdapter();
        private static SeasonTableAdapter _SeasonTableAdapter = new SeasonTableAdapter();
        private static UniverseTableAdapter _UniverseTableAdapter = new UniverseTableAdapter();
        private static UserYearTableAdapter _UserYearTableAdapter = new UserYearTableAdapter();
        private static CollegeTableAdapter _CollegeTableAdapter = new CollegeTableAdapter();
        private static view_PlayersTableAdapter _PlayerView = new view_PlayersTableAdapter();
        private static view_UniverseCharactersTableAdapter _UniverseCharacterView = new view_UniverseCharactersTableAdapter();
        private static UniverseCharacterTableAdapter _UniverseCharacterTableAdapter = new UniverseCharacterTableAdapter();
        private static view_ScheduleTableAdapter _ScheduleView = new view_ScheduleTableAdapter();
        private static view_YearsTableAdapter _YearView = new view_YearsTableAdapter();
        private static View_GameStatsTableAdapter _GameStatsView = new View_GameStatsTableAdapter();
        private static view_RegularSeasonTableAdapter _SeasonView = new view_RegularSeasonTableAdapter();
        private static view_PlayoffsTableAdapter _PlayoffsView = new view_PlayoffsTableAdapter();

        //Keep a tab of all of our ViewModels

        private static DataRowView _SelectedUniverse = null;
        public static DataRowView SelectedUniverse { get { return _SelectedUniverse; } set { _SelectedUniverse = value; } }

        #region Methods

        //Navigation
        public static void Switch(UserControl newPage)
        {
            _Window.Navigate(newPage);
        }

        public static void Switch(UserControl newPage, object state)
        {
            _Window.Navigate(newPage, state);
        }

        #endregion  

    }

任何关于存储全局变量的指针都会非常感激！

Answer 1

这是我使用MvvmCross做的事情，其中有一个用于存储所选语言的示例（需要全局变量）。我也对版本等使用相同的模式。这是我的SettingsPreferences类的一部分：

public static class Settings
{
    public static ISettings AppSettings
    {
        get
        {
            return CrossSettings.Current;
        }
    }
}

设置是nuget包的包装，用于保存内容（支持Android，iOS，Windows Store（Windows Phone 8.1和Windows Store 8.1）和WPF项目）：

var lang = SettingsPreferences.SelectedLanguage;

现在我的LanguageViewModel就像这样调用它：

SettingsPreferences.SelectedLanguage = "en";

要更新设置，只需：

template<typename From, typename To>
concept bool ConvertibleNoNarrow = requires(From f, To t) {
    t = { f };
};

template<typename T>
class Wrapper {
    T t;
public:
    Wrapper(ConvertibleNoNarrow<T> u) : t(u) { }

private:
    // should be PRIVATE
    void operator()() { }
};

int main() {
    Wrapper<long> w(1);

    // should not be able to call this!
    w();
}

它可以是真的。

MVVM中的全局变量

1 个答案: