DependencyResolver：传递参数 [英] DependencyResolver: Pass parameters

问题描述

我用autofac，可以传递参数给我的决心的方法。

I use autofac and can pass parameters to my resolve method.

我怎样才能做到这一点使用微软DependencyResolver接口？

How can I do this using microsofts DependencyResolver interface?

推荐答案

的的IDependencyResolver 不支持直接传递参数，因为我相信你已经注意到了。不过，既然你有Autofac引擎盖下，你能解决工厂的委托，使您能够在参数传递到底层服务：

The IDependencyResolver does not support passing parameters directly, as I'm sure you have noticed. However, since you have Autofac under the hood, you're able to resolve a factory delegate that enables you to pass on parameters to the underlying service:

var factory = dependencyResolver.GetService<Func<int, string, IService>>();
var service = factory(5, "42");

请注意：您可以使用函数功能代表或明确定义的工厂代表。更多关于此这里。

Note: you can either use Func delegates or explicitly defined factory delegates. More on this here.

对于生命周期范围：工厂代表必须从范围来解决所请求的服务可以达到了。考虑这个设置模拟MVC和的WebAPI怎么会是这样的：

Regarding lifetime scopes: factory delegates must be resolved from a scope where the requested service can be "reached". Consider this setup simulating how MVC or WebApi would look like:

var cb = new ContainerBuilder();
cb.RegisterType<X>().InstancePerMatchingLifetimeScope("http");
var application = cb.Build();
var request = application.BeginLifetimeScope("http");

通过这种设置，我们的 X 服务将只能在HTTP范围内使用。试图解决 X 从应用范围将失败，此消息：

With this setup, our X service will only be available in the http scope. Trying to resolve X from application scope will fail with this message:

没有一个标签匹配'HTTP'范围从可见光范围
      其中要求该实例。

No scope with a Tag matching 'http' is visible from the scope in which the instance was requested.

从要求范围将作为解决预期的：

Resolving from the request scope will work as expected:

var f = request.Resolve<Func<IX>>();
var x = f();

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