Question

我使用Structuremap作为我的依赖关系解析器。我正在尝试在我的Global.asax.cs文件上实现Container Per Request Pattern。

    public IContainer Container
    {
        get
        {
            return (IContainer)HttpContext.Current.Items["_Container"];
        }
        set
        {
            HttpContext.Current.Items["_Container"] = value;
        }
    }


   public void Application_BeginRequest()
   {
       Container = ObjectFactory.Container.GetNestedContainer();
   }

由于在未来的Structuremap版本中不支持ObjectFactory，我希望从DependencyResolver访问容器。怎么可能？

先谢谢。

Noufal

Answer 1

我自己遇到了这个问题，this was the best guide我可以找到用ASP.NET MVC的依赖性解析器注册StructureMap（通过CommonServiceLocator package）。

我已经复制并粘贴了上述文章的解决方案，但我建议您在原始文章中了解此解决方案的好处。

public class StructureMapDependencyResolver : ServiceLocatorImplBase
{
    private const string StructuremapNestedContainerKey = "Structuremap.Nested.Container";
    public IContainer Container { get; set; }

    private HttpContextBase HttpContext
    {
        get
        {
            var ctx = Container.TryGetInstance<HttpContextBase>();
            return ctx ?? new HttpContextWrapper(System.Web.HttpContext.Current);
        }
    }

    public IContainer CurrentNestedContainer
    {
        get { return (IContainer)HttpContext.Items[StructuremapNestedContainerKey]; }
        set { HttpContext.Items[StructuremapNestedContainerKey] = value; }
    }

    public StructureMapDependencyResolver(IContainer container)
    {
        Container = container;
    }

    protected override IEnumerable<object> DoGetAllInstances(Type serviceType)
    {
        return (CurrentNestedContainer ?? Container).GetAllInstances(serviceType).Cast<object>();
    }

    protected override object DoGetInstance(Type serviceType, string key)
    {
        var container = (CurrentNestedContainer ?? Container);

        if (string.IsNullOrEmpty(key))
        {
            return serviceType.IsAbstract || serviceType.IsInterface
                       ? container.TryGetInstance(serviceType)
                       : container.GetInstance(serviceType);
        }

        return container.GetInstance(serviceType, key);
    }

    public void Dispose()
    {
        if (CurrentNestedContainer != null)
        {
            CurrentNestedContainer.Dispose();
        }

        Container.Dispose();
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        return DoGetAllInstances(serviceType);
    }

    public void DisposeNestedContainer()
    {
        if (CurrentNestedContainer != null)
            CurrentNestedContainer.Dispose();
    }

    public void CreateNestedContainer()
    {
        if (CurrentNestedContainer != null) return;
        CurrentNestedContainer = Container.GetNestedContainer();
    }
}

然后您可以像这样设置解析器：

public class MvcApplication : System.Web.HttpApplication
{
    public static StructureMapDependencyResolver StructureMapResolver { get; set; }

    protected void Application_Start()
    {
        ...

        // Setup your Container before 
        var container = IoC.Initialize();
        StructureMapResolver = new StructureMapDependencyResolver(container);
        DependencyResolver.SetResolver(StructureMapResolver);
    }

    protected void Application_BeginRequest(object sender, EventArgs e)
    {
        StructureMapResolver.CreateNestedContainer();
    }

    protected void Application_EndRequest(object sender, EventArgs e)
    {
        StructureMapResolver.DisposeNestedContainer();
    }    
}

这种配置的最佳结果是每个请求都会收到一个新的子容器，并在每个请求结束时处理容器。

Answer 2

我只是尝试了这个和它的工作，请让我，如果它不是最好的方式。

StructuremapMvc.StructureMapDependencyScope.Container

Answer 3

有两个依赖项解析器，一个用于ASP.NET MVC，另一个用于ASP.NET Web Api

Web Api：使用 WebApiContrib.IoC.StructureMap.StructureMapResolver

MVC：使用 StructureMapDependencyResolver

public class StructureMapDependencyResolver : StructureMapDependencyScope, IDependencyResolver
{
    public StructureMapDependencyResolver(IContainer container)
        : base(container)
    {
    }

    public IDependencyScope BeginScope()
    {
        var child = Container.GetNestedContainer();
        return new StructureMapDependencyResolver(child);
    }
}

public class StructureMapDependencyScope : ServiceLocatorImplBase, IDependencyScope
{
    protected readonly IContainer Container;

    public StructureMapDependencyScope(IContainer container)
    {
        if (container == null)
        {
            throw new ArgumentNullException(nameof(container));
        }
        Container = container;
    }

    public void Dispose()
    {
        Container.Dispose();
    }

    public override object GetService(Type serviceType)
    {
        if (serviceType == null)
        {
            return null;
        }
        return serviceType.IsAbstract || serviceType.IsInterface
            ? Container.TryGetInstance(serviceType)
            : Container.GetInstance(serviceType);
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        return Container.GetAllInstances(serviceType).Cast<object>();
    }

    protected override IEnumerable<object> DoGetAllInstances(Type serviceType)
    {
        return Container.GetAllInstances(serviceType).Cast<object>();
    }

    protected override object DoGetInstance(Type serviceType, string key)
    {
        if (string.IsNullOrEmpty(key))
        {
            return serviceType.IsAbstract || serviceType.IsInterface
                ? Container.TryGetInstance(serviceType)
                : Container.GetInstance(serviceType);
        }
        return Container.GetInstance(serviceType, key);
    }
}

用法如下......

public static class Ioc
{
    public static void Config()
    {
        var container = InitializeContainer();

        var webApiDependencyResolver = new StructureMapResolver(container);
        GlobalConfiguration.Configuration.DependencyResolver = webApiDependencyResolver;

        var mvcDependencyResolver = new StructureMapDependencyResolver(container);
        DependencyResolver.SetResolver(mvcDependencyResolver);
    }
}

public class WebApiApplication : System.Web.HttpApplication
{
    protected void Application_Start()
    {
        Ioc.Config();
        ...
    }
}

如何从Asp.Net MVC 5依赖解析器获取Structuremap IContainer实例

3 个答案: