如何在与 Castle Windsor DI 容器相同的上下文中重用瞬态依赖项

Question

如果我有以下设置，当在同一上下文中创建对象时，如何配置我的容器以使用同一数据库

public class Database { }
public interface IRepository { Database Database { get; } }
public interface IFooRepository : IRepository { }
public interface IBarRepository : IRepository { }

public class FooRepository : IFooRepository
{
    public Database Database { get; private set; }
    public FooRepository(Database database) { this.Database = database; }
}

public class BarRepository : IBarRepository
{
    public Database Database { get; private set; }
    public BarRepository(Database database) { this.Database = database; }
}

public class Consumer
{
    public IFooRepository fooRepository { get; private set; }
    public IBarRepository barRepository { get; private set; }
    public Consumer(IFooRepository fooRepository, IBarRepository barRepository)
    {
        this.fooRepository = fooRepository;
        this.barRepository = barRepository;
    }
}

[TestClass]
public class ConfigurationTest
{
    private IWindsorContainer container;

    [TestMethod]
    public void SameDatabaseIsUsed()
    {
        Consumer consumer = container.Resolve<Consumer>();
        IFooRepository fooRepository = consumer.fooRepository;
        IBarRepository barRepository = consumer.barRepository;
        Assert.AreEqual(fooRepository.Database, barRepository.Database); //FAILS
    }

    [TestMethod]
    public void DifferentDatabaseIsUsed()
    {
        Consumer consumer = container.Resolve<Consumer>();
        IFooRepository fooRepository = consumer.fooRepository;
        Consumer consumer2 = container.Resolve<Consumer>();
        IBarRepository barRepository = consumer2.barRepository;
        Assert.AreNotEqual(fooRepository.Database, barRepository.Database); //PASSES
    }

    [TestInitialize]
    public void SetUp()
    {
        container = new WindsorContainer();
        container.Register(
            Component.For<Database>().ImplementedBy<Database>().LifeStyle.Transient,
            AllTypes.FromThisAssembly()
                    .BasedOn<IRepository>().WithService.FromInterface()
                    .Configure(c => c.LifeStyle.Transient),
            Component.For<Consumer>().ImplementedBy<Consumer>().LifeStyle.Transient
                    );

    }
}

编辑： 我尝试过使用自定义生活方式，但我无法弄清楚我可以使用什么来检测我已经切换了上下文

public class DatabaseLifestyleManager : AbstractLifestyleManager
{
    private CreationContext context;
    private Database database;

    private Database Database
    {
        get
        {
            if (database == null) database = new Database();
            return database;
        }
        set 
        {
            database = null;
        }
    }

    public override object Resolve(CreationContext context)
    {
        if (this.context!=null && this.context.??? == context.???)
            return Database;
        else
        {
            this.context = context;
            Database = null;
            return Database;
        }

    }

    public override void Dispose()
    {
        database = null;
        context = null;
    }
}
......
Component.For<Database>().ImplementedBy<Database>().LifeStyle.Custom(typeof(DatabaseLifestyleManager)

Answer 1

在请求瞬态组件时，您总是会得到一个新实例，如果它不是您想要的，请不要使用瞬态生活方式:-)

为什么你要注册一个瞬态组件，却试图根据某种“上下文”来解析同一个对象？很可能这种生活方式不适合这种情况，如果你试图强迫它变成不合适的东西，你会遇到麻烦。

您想要的是一种情境式生活方式，在 this article 中提到。 以下两个要点对此有一个实现：

• http://gist.github.com/400979
• http://gist.github.com/400980

这将允许您这样做：

Register(Component.For<Database>().LifeStyle.Scoped())

[TestMethod]
public void SameDatabaseIsUsed()
{
    using (container.BeginScope())
    {
        Consumer consumer = container.Resolve<Consumer>();
        IFooRepository fooRepository = consumer.fooRepository;
        IBarRepository barRepository = consumer.barRepository;
        Assert.AreEqual(fooRepository.Database, barRepository.Database); // YAY!
    }
}

希望这会有所帮助！

Answer 2

contextual lifestyle 包含在 Castle.Windsor.Lifestyles contrib project 中。

Answer 3

我自己通过实现 IDisposable 提出了这个解决方案，这样我就可以为数据库使用一种 sessionscope

这是处理这种情况的有效方法吗？

所有测试都通过了，但有一些附加功能，必须在我未来的所有存储库使用者中实现：

public class Database { }
public interface IRepository : IDisposable { Database Database { get; } }
public interface IFooRepository : IRepository { }
public interface IBarRepository : IRepository { }

public abstract class BaseRepository : IDisposable
{
    public BaseRepository(Database database) { this.Database = database; }
    public Database Database { get; private set; }
    public void Dispose() { Database = null; }
}

public class FooRepository : BaseRepository, IFooRepository
{
    public FooRepository(Database database) : base(database) { }
}

public class BarRepository : BaseRepository, IBarRepository
{
    public BarRepository(Database database) : base(database) { }
}

public abstract class BaseConsumer : IDisposable
{
    public abstract void Dispose();
}

public class Consumer : BaseConsumer
{
    public IFooRepository fooRepository { get; private set; }
    public IBarRepository barRepository { get; private set; }

    public Consumer(IFooRepository fooRepository, IBarRepository barRepository)
    {
        this.fooRepository = fooRepository;
        this.barRepository = barRepository;
    }

    public override void Dispose()
    {
        this.fooRepository.Dispose();
        this.barRepository.Dispose();
    }
}

[TestClass]
public class ConfigurationTest
{
    private IWindsorContainer container;

    [TestMethod]
    public void SameDatabaseIsUsed()
    {
        IFooRepository fooRepository;
        IBarRepository barRepository;
        using (Consumer consumer = container.Resolve<Consumer>())
        {
            fooRepository = consumer.fooRepository;
            barRepository = consumer.barRepository;
            Assert.AreEqual(fooRepository.Database, barRepository.Database); //FAILS
        }
        Assert.IsNull(fooRepository.Database);
        Assert.IsNull(barRepository.Database);

    }

    [TestMethod]
    public void DifferentDatabaseIsUsed()
    {
        IFooRepository fooRepository;
        IBarRepository barRepository;

        using (Consumer consumer = container.Resolve<Consumer>())
            fooRepository = consumer.fooRepository;

        Assert.IsNull(fooRepository.Database);

        using (Consumer consumer2 = container.Resolve<Consumer>())
            barRepository = consumer2.barRepository;

        Assert.IsNull(barRepository.Database);
    }

    [TestInitialize]
    public void SetUp()
    {
        container = new WindsorContainer().Register(
            Component.For<Database>().ImplementedBy<Database>().LifeStyle.Singleton,
            AllTypes.FromThisAssembly()
                    .BasedOn<IRepository>().WithService.FromInterface()
                    .Configure(c => c.LifeStyle.Transient),
            Component.For<Consumer>().ImplementedBy<Consumer>().LifeStyle.Transient
                    );
    }
}