Question

我正在使用Castle Windsor的ASP.NET MVC 4项目。其中一个控制器依赖于MembershipService：

public class FooController : Controller
{
    private readonly MembershipService MembershipService;

    public FooController( MembershipService membershipService )
    {
        MembershipService = membershipService;
    }

    [Authorize( Roles = "Administrator" )]
    public ActionResult DoSomething()
    {
        var user = MembershipService.GetUser( User.Identity.Name );

        // etc...
    }
}

当我开始为这个控制器编写单元测试时（使用Moq），我遇到了一个问题：

private Mock<MembershipService> membershipServiceMock;

[TestInitialize]
public void MyTestInitialize()
{
    membershipServiceMock = new Mock<MembershipService>();
}

[TestMethod]
public void DoSomethingReturnsWhatever()
{
    var controller = new FooController( membershipServiceMock.Object );

    // etc...
}

测试失败，因为Castle抛出异常：

Castle.DynamicProxy.InvalidProxyConstructorArgumentsException: Can not instantiate proxy of class: MembershipService.
Could not find a parameterless constructor.

我决定创建一个MembershipService可以实现的接口，因为这就是我们的应用程序通常是如何设计的：

public interface IMembershipService
{
    User GetCurrentUser( string userName );
}

我更新了控制器以使用界面，但现在Castle引发了另一个异常：

[HandlerException: Handler for IMembershipService was not found.]
   Castle.MicroKernel.Resolvers.DefaultDependencyResolver.TryGetHandlerFromKernel(DependencyModel dependency, CreationContext context) +210
   Castle.MicroKernel.Resolvers.DefaultDependencyResolver.ResolveFromKernelByType(CreationContext context, ComponentModel model, DependencyModel dependency) +38

[DependencyResolverException: Missing dependency.
Component FooController has a dependency on IMembershipService, which could not be resolved.
Make sure the dependency is correctly registered in the container as a service, or provided as inline argument.]

显然我没有在Castle上注册IMembershipService，所以我改变了我的安装程序：

container.Register( Component.For<MembershipService>() );

对此：

container.Register( Component.For( typeof(IMembershipService) )
         .ImplementedBy( typeof(MembershipService) ) );

现在Castle引发了另一个例外：

Configuration Error
Parser Error Message: Activation error occurred while trying to get instance of type MembershipService, key ""

这是web.config文件的相关部分。违规行是以add name="MyRoleProvider"：

开头的行

<authentication mode="Windows" />
<roleManager enabled="true" defaultProvider="MyRoleProvider">
  <providers>
    <clear />
    <add name="MyRoleProvider" type="MyRoleProvider" applicationName="MyApplication" autoCreateRole="true" autoCreateUser="true" />
    <add name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider" applicationName="/" />
  </providers>
</roleManager>

这是因为MyRoleProvider也引用了MembershipService：

public class MyRoleProvider : RoleProvider
{
    private MembershipService MembershipService;

    public override void Initialize( string name, NameValueCollection config )
    {
        MembershipService = ServiceLocator.Current.GetInstance<MembershipService>();

        // blah blah blah...
    }
}

我尝试更改MyRoleProvider中MembershipService字段的类型，如下所示：

public class MyRoleProvider : RoleProvider
{
    private IMembershipService MembershipService;

但它仍会抛出相同的异常（“尝试获取MembershipService类型的实例时发生激活错误...”）。到目前为止我管理的唯一方法就是通过像这样注册IMembershipService 和 MembershipService：

container.Register( Component.For<MembershipService>() );
container.Register( Component.For( typeof(IMembershipService) )
         .ImplementedBy( typeof(MembershipService) ) );

我很确定我不应该两次注册。那么我怎么能解决这个问题呢？在这一点上，如果我能继续编写单元测试，我会很高兴将应用程序与会员服务紧密结合。但是，如果它不涉及主要的体系结构变化，那么解耦解决方案也会很好。

修改

堆栈追踪：

at Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance(Type serviceType, String key) in c:\Projects\CommonServiceLocator\main\Microsoft.Practices.ServiceLocation\ServiceLocatorImplBase.cs:line 53
at Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance[TService]() in c:\Projects\CommonServiceLocator\main\Microsoft.Practices.ServiceLocation\ServiceLocatorImplBase.cs:line 90
at MyRoleProvider.Initialize(String name, NameValueCollection config) in d:\Code\MyApplication\MyRoleProvider.cs:line 51
at System.Web.Configuration.ProvidersHelper.InstantiateProvider(ProviderSettings providerSettings, Type providerType)

Answer 1

您已定义了IMembershipService

public interface IMembershipService
{
    User GetCurrentUser( string userName );
}

现在更改你的FooController

public class FooController : Controller
{
    private readonly IMembershipService MembershipService;

    public FooController( IMembershipService membershipService )
    {
        MembershipService = membershipService;
    }

    [Authorize( Roles = "Administrator" )]
    public ActionResult DoSomething()
    {
        var user = MembershipService.GetUser( User.Identity.Name );

        // etc...
    }
}

转到并将代码MembershipService中的任何位置更改为IMembershipService，如FooController中所示。现在，在Castle

中注册 IMembershipService

container.Register( Component.For( typeof(IMembershipService) )
         .ImplementedBy( typeof(MembershipService) ) );

现在更改单元测试

private Mock<IMembershipService> membershipServiceMock;

[TestInitialize]
public void MyTestInitialize()
{
    membershipServiceMock = new Mock<IMembershipService>();
}

[TestMethod]
public void DoSomethingReturnsWhatever()
{
    var controller = new FooController( membershipServiceMock.Object );

    // etc...
}

如何将我的申请与会员服务分开？

修改

1 个答案: