Autofac註冊多個容器

Question

我有一個MVC應用程序，我正在使用Autofac解決依賴關係。

我有一種情況，我必須創建2個容器，運行時應根據條件決定使用哪個容器。

條件是如果控制器Home被調用，我需要使用container1，否則我必須使用container2。

Application_Start是我註冊容器的地方。

我不知道如何在運行時發生這種情況。任何幫助，高度讚賞。

感謝來自不同的容器，讓控制器決心

Answer 1

的一個原因是，如果你的應用程序由多個獨立的模塊。在這種情況下，您可能不希望模塊互相影響，並且每個模塊都有一個容器是合理的。然而，在幾乎所有其他情況下，擁有多個容器實例都沒有意義。

所以，如果你需要這個，你需要建立自己的定製IControllerFactory，可以根據控制器類型切換容器。舉例來說，這樣的事情：

internal sealed class MultiplContainerControllerFactory : IControllerFactory 
{ 
    public IController CreateController(RequestContext requestContext, string controllerName) 
    { 
     var factory = this.GetFactory(requestContext); 
     var controller = factory.CreateController(requestContext, controllerName); 

     // By storing the factory in the request items for this controller, 
     // we allow it to be easily retrieved 
     // during ReleaseController and delegate releasing to the correct controller. 
     HttpContext.Current.Items["ContrFct_" + controller.GetType().FullName] = factory; 

     return controller; 
    } 

    public SessionStateBehavior GetControllerSessionBehavior(RequestContext requestContext, 
     string controllerName) 
    { 
     var factory = this.GetFactory(requestContext); 
     return factory.GetControllerSessionBehavior(requestContext, controllerName); 
    } 

    public void ReleaseController(IController controller) 
    { 
     var controllerFactory = (IControllerFactory)HttpContext.Current.Items["ContrFct_" + 
      controller.GetType().FullName]; 

     controllerFactory.ReleaseController(controller); 
    } 

    private IControllerFactory GetFactory(RequestContext context) 
    { 
     // return the module specific factory based on the requestcontext 
    } 
} 

除此之外，您將需要有每個集裝箱特殊AutofacControllerFactory。這可能看起來像這樣：

public sealed class AutofacControllerFactory : DefaultControllerFactory 
{ 
    public readonly IContainer Container; 
    private readonly string moduleName; 

    public AutofacControllerFactory(IContainer container, string moduleName) 
    { 
     this.Container = container; 
     this.moduleName = moduleName; 
    } 

    protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType) 
    { 
     if (controllerType == null) 
     { 
      // The base method throws an expressive 404 HTTP error. 
      base.GetControllerInstance(requestContext, controllerType); 
     } 

     // We need to start a new lifetime scope when resolving a controller. 
     // NOTE: We can apply MatchingScopeLifetimeTags.RequestLifetimeScopeTag to the BeginLifetimeScope 
     // method and in this case we can use .InstancePerRequest(), but in that case it becomes impossible to 
     // verify the DI configuration in an integration test. 
     ILifetimeScope lifetimeScope = this.Container.BeginLifetimeScope(); 

     // We need to store this lifetime scope during the request to allow to retrieve it when the controller 
     // is released and to allow to dispose the scope. Memory leaks will be ensured if we don't do this. 
     HttpContext.Current.Items[controllerType.FullName + "_lifetimeScope"] = lifetimeScope; 

     // This call will throw an exception when we start making registrations with .InstancePerRequest, 
     // because the WebRequest functionality of Autofac is tied to the AutofacDependencyResolver, which we 
     // don't use here. We can't use the AutofacDependencyResolver here, since it stores the created lifetime 
     // scope in the HttpContext.Items, but it uses a fixed key, which means that if we resolve multiple 
     // controllers for different application modules, they will all reuse the same lifetime scope, while 
     // this scope originates from a single container. 
     try 
     { 
      return (IController)lifetimeScope.Resolve(controllerType); 
     } 
     catch (Exception ex) 
     { 
      lifetimeScope.Dispose(); 

      throw new InvalidOperationException("The container of module '" + this.moduleName + 
       "' failed to resolve controller " + controllerType.FullName + ". " + ex.Message, ex); 
     } 
    } 

    [DebuggerStepThrough] 
    public override void ReleaseController(IController controller) 
    { 
     try 
     { 
      base.ReleaseController(controller); 
     } 
     finally 
     { 
      var scope = (ILifetimeScope)HttpContext.Current 
       .Items[controller.GetType().FullName + "_lifetimeScope"]; 

      scope.Dispose(); 
     } 
    } 
}