C# IoC：实现条件注入

Question

我想创建一个简单的游戏并使用其中一个 IoC 容器。每个游戏都有玩家，所以我想把他们注入Gameclass。问题是，可能有不同类型的玩家。第一个玩家将始终是人类（设备所有者；）），但他的对手：人类（游戏和传球）、机器人或在线（人类，但通过互联网游戏）。

这是代码。有不同的玩家：

public class Human : IPlayer
{
    public int Id { get; set; }
    public string Name { get; set; }
    public PlayerType Type { get; set; }
}

public class Bot : Human
{
}

public class OnlinePlayer : Human
{
}

public interface IPlayer
{
    int Id { get; set; }
    string Name { get; set; }
    PlayerType Type { get; set; }
}

和Game class:

public class Game : IGame
{
    public GameType Type { get; private set; }
    public List<IPlayer> Players { get; private set; }

    public Game(GameType type, List<IPlayer> players)
    {
        Type = type;
        Players = players;
    }
}

public interface IGame
{
    GameType Type { get; }
    List<IPlayer> Players { get; }
}

如您所见，我在游戏容器中注入了玩家列表。这是我的问题：

如果类型不同 GameType，我如何解决 List<IPlayer>？

if GameType = 单人游戏 -> 注入人类和机器人

if GameType = Pass and play -> Inject Human and Human

if GameType = Online game -> Inject Human and OnlinePlayer

Answer 1

你可以使用 Ninject，我在我工作的一些项目中使用了这种方法，非常简单，请参阅 Ninject 项目站点：https://github.com/ninject/Ninject/wiki/Contextual-Binding

关于您的评论，我的建议是将实现 IGame 接口的具体 classes 中的游戏类型分开，参见示例：

public interface IGame
{
    GameType Type { get; }
    ReadOnlyCollection<IPlayer> Players { get; }
}

public class GameSingle : IGame
{
    public GameSingle(List<IPlayer> players)
    {
        Players = players.AsReadOnly();
    }

    public GameType Type => GameType.Single;
    public ReadOnlyCollection<IPlayer> Players { get; }
}

public class GameOnline : IGame
{
    public GameOnline(List<IPlayer> players)
    {
        Players = players.AsReadOnly();
    }

    public GameType Type => GameType.Online;
    public ReadOnlyCollection<IPlayer> Players { get; }
}

public class GamePlayAndPass : IGame
{
    public GamePlayAndPass(List<IPlayer> players)
    {
        Players = players.AsReadOnly();
    }

    public GameType Type => GameType.PassAndPlay;
    public ReadOnlyCollection<IPlayer> Players { get; }
}

现在在ninject的模块中：

        Kernel.Bind<IPlayer>().To<Bott>().WhenInjectedExactlyInto<GameSingle>();
        Kernel.Bind<IPlayer>().To<OnlinePlayer>().WhenInjectedExactlyInto<GameOnline>();
        Kernel.Bind<IPlayer>().To<Human>().WhenInjectedExactlyInto<GamePlayAndPass>();
        Kernel.Bind<IPlayer>().To<Human>();

然后你只需要定义何时何地注入 IGame 具体 class XD。

Answer 2

没有理由让它变得比它必须的更复杂。你可以这样写 in an Abstract Factory:

if (gameType == GameType.Single)
    return new Game(
        GameType.Single,
        new List<IPlayer> { CreateHuman(); CreateBot() });
else if (gameType == GameType.PassAndPlay)
    return new Game(
        GameType.PassAndPlay,
        new List<IPlayer> { CreateHuman(); CreateHuman() });
else
    return new Game(
        GameType.Online,
        new List<IPlayer> { CreateHuman(); CreateOnlinePlayer() });

C# IoC：实现条件注入

C# IoC: Implementing conditional injection

.net

c#

dependency-injection

inversion-of-control