我的 WebApi 服务在使用运行时 Unity 配置时可以工作,但是当我将其更改为使用 web.config 中的 Unity 配置时,我收到错误
"尝试创建类型的控制器时出错 "我的控制器"。确保控制器具有无参数 公共构造函数。
我正在使用 Unity 和 Unity.WebApi nuget 包。
使用运行时配置(工作正常(时,我的RegisterComponents
方法如下所示;
public static void RegisterComponents()
{
IUnityContainer container = new UnityContainer();
container.RegisterType<Repository.Interfaces.IRepository, DataAccess.OracleRepository>(new HierarchicalLifetimeManager());
GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);
}
在 web.config 中使用 xml 配置时,我使用它;
public static void RegisterComponents()
{
IUnityContainer container = new UnityContainer().LoadConfiguration();
GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);
}
我在 web.config 中的 Unity 部分看起来像这样;
<unity xmlns="http://schemas.microsoft.com/practices/2010/unity">
<alias alias="IRepository" type="Repository.Interfaces.IRepository, Repository"/>
<alias alias="OracleRepository" type="DataAccess.OracleRepository, DataAccess"/>
<container>
<register type="IRepository" mapTo="OracleRepository" name="oracle">
<lifetime type="hierarchical"/>
</register>
</container>
</unity>
但是,此时当我转到 url 时,应用程序会给出错误;
<Error>
<Message>An error has occurred.</Message>
<ExceptionMessage>An error occurred when trying to create a controller of type 'MyController'. Make sure that the controller has a parameterless public constructor.</ExceptionMessage>
<ExceptionType>System.InvalidOperationException</ExceptionType>
<StackTrace>at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType) at System.Web.Http.Controllers.HttpControllerDescriptor.CreateController(HttpRequestMessage request) at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()</StackTrace>
<InnerException>
<Message>An error has occurred.</Message>
<ExceptionMessage>Resolution of the dependency failed, type = "GatewayService.Controllers.MyController", name = "(none)". Exception occurred while: while resolving. Exception is: InvalidOperationException - The current type, Repository.Interfaces.IRepository, is an interface and cannot be constructed. Are you missing a type mapping? ----------------------------------------------- At the time of the exception, the container was: Resolving GatewayService.Controllers.MyController,(none) Resolving parameter "respository" of constructor GatewayService.Controllers.MyController(Repository.Interfaces.IRepository respository) Resolving Repository.Interfaces.IRepository,(none)</ExceptionMessage>
<ExceptionType>Microsoft.Practices.Unity.ResolutionFailedException</ExceptionType>
...
官方文档,
<register>
元素
<register>
元素是任何 配置文件。它使您能够指定类型映射和 类型的注入配置。如果指定名称,则该名称 用于类型映射。如果不指定名称,则会创建 指定类型的默认映射。您可以指定一个 每个映射的生存期管理器。如果没有显式生存期管理器 为某种类型配置,它使用瞬态生存期管理器。
所以我建议从 web 配置中的注册标签中删除 name 属性。