温莎城堡与多个构造函数 [英] Castle Windsor with Multiple Constructors

问题描述

我目前正在进行一个简单的C＃.NET应用程序的转换，从使用Ninject到最新版本的Castle Windsor。

I am currently undertaking a conversion, from to the use of Ninject, to the current release of Castle Windsor for a simple C# .NET application.

在大多数情况下，转换进行得很好，并且容器的实现已完美执行。但是我的存储库对象有一个小问题。

For the most part, the conversion has gone well and the implementation of the containers has executed flawlessly. I am however having a small issue with my repository objects.

我有一个用户存储库对象，其编码方式如下：

I have a user repository object that is coded in the following fashion:

public class UserRepository : IUserRepository {
    public UserRepository(IObjectContext objectContext)  {
        // Check that the supplied arguments are valid.
        Validate.Arguments.IsNotNull(objectContext, "objectContext");

        // Initialize the local fields.
        ObjectContext = objectContext;
    }

    public UserRepository(IObjectContextFactory factory) 
        : this(factory.CreateObjectContext()) { 
    }

    // -----------------------------------------------
    // Insert methods and properties...
    // -----------------------------------------------
}

对应于此代码，我已经在应用程序的配置文件中设置了以下条目：

To correspond to this code, I have setup the following entries in my application's configuration file:

<castle>
    <components>
        <component id="objectContextFactory" lifestyle="custom"
                   customLifestyleType="Common.Infrastructure.PerWebRequestLifestyleManager, Common.Castle"
                   service="Project.DAL.Context.IObjectContextFactory, Project.DAL.LINQ"
                   type="project.DAL.Context.ObjectContextFactory, Project.DAL.LINQ">
        </component>
        <component id="userRepository" lifestyle="custom"
                   customLifestyleType="Common.Infrastructure.PerWebRequestLifestyleManager, Common.Castle"
                   service="Project.BL.Repository.IUserRepository, Project.BL"
                   type="Project.BL.Repository.UserRepository, Project.BL.LINQ">
            <parameters>
              <factory>${objectContextFactory}</factory>
            </parameters>
        </component>
    </components>
</castle>

对我来说，一切看起来都应该如此。当我尝试解析IObjectContextFactory服务的实例时，我检索了一个ObjectContextFactory对象。当我尝试解决IUserRepository服务的实例时，就会出现我的问题。我受到以下令人愉快的例外对待：

To me, everything looks like it should. When I attempt to resolve an instance of the IObjectContextFactory service, I retrieve an ObjectContextFactory object. My problem comes in when I try and resolve an instance of the IUserRepository service. I am treated to the following delightful exception:

无法创建组件 userRepository，因为它具有要满足的依赖关系。
userRepository正在等待以下依赖项：

Can't create component 'userRepository' as it has dependencies to be satisfied. userRepository is waiting for the following dependencies:

服务：

-未注册的SandCastle.DAL.Context.IObjectContext。

我已经尽力了想想这个。因此，对您来说，stackoverflow的读者来说，我说：有任何想法吗？

I've tried everything I can think of on this. So, unto you stackoverflow readers, I say: got any ideas?

推荐答案

这可能被认为是一个错误（对于

This might be regarded as a bug (and indeed for cases like this it's fixable) but it's kindof a by-design feature.

Windsor尝试匹配它可以满足的最贪婪的构造函数（参数最多的一个）。

Windsor tries to match the greediest constructor (one with the most parameters) it can satisfy.

但是，在您的情况下，有两个构造函数的参数数量最多（一个），因此Windsor只会选择第一个，其中第一个的含义是不确定的

However in your case, there are two constructors that have the greatest number of parameters (of one), so Windsor just picks the first, where what the "first" means is undefined.

实际上，如果您在源代码中切换了构造函数的顺序，则您的代码将开始工作，尽管这是一种hack，它依赖于未记录的行为并且不执行此操作。 。

indeed if you switch the order of your constructors in your source code your code will start working, although it's a hack, relying on undocumented behavior and don't do it.

让我们回到开始的地方吗？

Let's go back to where we started shall we?

我说温莎很困惑，因为没有<

I said Windsor is confused because there's no single greediest constructor it can satisfy.

快速且定义明确的修复方法是在其中一个c中添加一个伪参数从而使它们具有不同数量的参数：

Quick and well-defined fix would be to add a fake parameter to one of th constructors so that they have different numbers of parameters:

public class UserRepository : IUserRepository {
    public UserRepository(IObjectContext objectContext, object fakeIgnoreMe)  {
        // Check that the supplied arguments are valid.
        Validate.Arguments.IsNotNull(objectContext, "objectContext");
        // ignoring fake additional argument
        // Initialize the local fields.
        ObjectContext = objectContext;
    }

    public UserRepository(IObjectContextFactory factory) 
        : this(factory.CreateObjectContext()) { 
    }

    // -----------------------------------------------
    // Insert methods and properties...
    // -----------------------------------------------
}

请将此问题报告给城堡用户列表或直接发布跟踪器，以便对其进行修复。

Please report this issue to Castle users list or straight to issue tracker so that it will get fixed.

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