使用统一xml配置向嵌套泛型注册接口 [英] Using unity xml config to register an interface with nested generics

问题描述

如果我有一个实现通用接口的类，那么使用unity xml config配置它就可以。

If I have a class that implements a generic interface it works fine to configure it using the unity xml config.

public interface IReader<T> { }

public class Fund { }

public class FundReader : IReader<Fund> { }

和unity xml：

and the unity xml:

<unity xmlns="http://schemas.microsoft.com/practices/2010/unity">
  <namespace name="System.ComponentModel" />
  <namespace name="TestUnityIssue" />
  <assembly name="TestUnityIssue" />
  <container>
    <register type="IReader[Fund]" mapTo="FundReader" />
  </container>
</unity>

这个工程只需使用以下代码：

And this works just using the following code:

var container = new UnityContainer().LoadConfiguration();
var fundReader = container.Resolve<IReader<Fund>>();

然而，在某些情况下，在阅读器中使用了一种类型的包装。例如，添加以下两个类：

However, in some cases there is a wrapper around the type used in the reader. For example, adding the following two classes:

public class Wrapper<T> { }

public class WrappedFundReader : IReader<Wrapper<Fund>> { }

如果我将以下内容添加到统一配置中：

and if I add the following to the unity config:

<register type="IReader[Wrapper[Fund]]" mapTo="WrappedFundReader" />

然后尝试使用以下方法解决它：

and then try to resolve it using:

var wrappedReader = container.Resolve<IReader<Wrapper<Fund>>>();

我收到以下异常：

I get the following exception:

InvalidOperationException - The current type,
TestUnityIssue.IReader`1[TestUnityIssue.Wrapper`1[TestUnityIssue.Fund]],
is an interface and cannot be constructed. Are you missing a type
mapping?

我可以通过使用代码而不是xml来配置它：

I can get around this by configuring it using code instead of xml:

container.RegisterType<IReader<Wrapper<Fund>>, WrappedFundReader>();

或者我可以创建一个介于两者之间并使用它的接口：

or I can create an interface that goes between and use that instead:

public interface IWrappedReader<T> : IReader<Wrapper<T>> { }

public class WrappedFundReader : IWrappedReader<Fund>

，配置将变为：

and the config would change to:

<register type="IWrappedReader[Fund]" mapTo="WrappedFundReader" />

它仍然会给我一个实例，可以转换为 IReader< Wrapper< ; Fund>> ，但它似乎应该能够使这个工作与统一配置。

It will still give me an instance that I can cast to IReader<Wrapper<Fund>>, but it seems like I should be able to make this work with the unity config.

我错过了什么来完成这项工作？

What am I missing to make this work?

（如果还尝试创建特定的别名，并且无法使其工作）

(If also tried creating specific aliases and wasn't able to get that to work either)

推荐答案

别名为我工作...

<unity xmlns="http://schemas.microsoft.com/practices/2010/unity">
    <alias alias="WrappedFund" type="TestUnityIssue.Wrapper`1[[TestUnityIssue.Fund, TestUnityIssue, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]], TestUnityIssue, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
    <namespace name="TestUnityIssue" />
    <assembly name="TestUnityIssue" />
    <container>
        <register type="IReader[Fund]" mapTo="FundReader" />
        <register type="IReader[WrappedFund]" mapTo="WrappedFundReader" />
    </container>
</unity>

这些都解决了...

var fundReader = container.Resolve<IReader<Fund>>();
var wrappedReader = container.Resolve<IReader<Wrapper<Fund>>>();

并且根据您的情况，您可能会得到比完整的AssemblyQualifiedName更少的值。 。

and depending on your situation, you may be able to get away with less than the full AssemblyQualifiedName...

<alias alias="WrappedFund" type="TestUnityIssue.Wrapper`1[[TestUnityIssue.Fund, TestUnityIssue]], TestUnityIssue" />

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