升级到sitecore 8后WEB API调用出现500错误

最近，我们从Sitecore 7.5升级到Sitecore 8.0。升级后，自定义Web API调用开始返回500个错误代码，但以下情况除外：

Message:"An error has occurred."
ExceptionMessage:"ValueFactory attempted to access the Value property of this instance."
ExceptionType:"System.InvalidOperationException"
StackTrace:"   at System.Lazy`1.CreateValue()
   at System.Lazy`1.LazyInitValue()
   at System.Web.Http.Dispatcher.DefaultHttpControllerSelector.GetControllerMapping()
   at System.Web.Http.Routing.AttributeRoutingMapper.AddRouteEntries(SubRouteCollection collector, HttpConfiguration configuration, IInlineConstraintResolver constraintResolver, IDirectRouteProvider directRouteProvider)
   at System.Web.Http.Routing.AttributeRoutingMapper.<>c__DisplayClass2.<>c__DisplayClass4.<MapAttributeRoutes>b__1()
   at System.Web.Http.Routing.RouteCollectionRoute.EnsureInitialized(Func`1 initializer)
   at System.Web.Http.Routing.AttributeRoutingMapper.<>c__DisplayClass2.<MapAttributeRoutes>b__0(HttpConfiguration config)
   at System.Web.Http.CorsHttpConfigurationExtensions.<>c__DisplayClass3.<AddCorsMessageHandler>b__0(HttpConfiguration config)
   at System.Web.Http.HttpConfiguration.ApplyControllerSettings(HttpControllerSettings settings, HttpConfiguration configuration)
   at System.Web.Http.Controllers.HttpControllerDescriptor.InvokeAttributesOnControllerType(HttpControllerDescriptor controllerDescriptor, Type type)
   at System.Web.Http.Dispatcher.DefaultHttpControllerSelector.InitializeControllerInfoCache()
   at System.Lazy`1.CreateValue()
   at System.Lazy`1.LazyInitValue()
   at System.Web.Http.Dispatcher.DefaultHttpControllerSelector.GetControllerMapping()
   at System.Web.Http.Routing.AttributeRoutingMapper.AddRouteEntries(SubRouteCollection collector, HttpConfiguration configuration, IInlineConstraintResolver constraintResolver, IDirectRouteProvider directRouteProvider)
   at System.Web.Http.Routing.AttributeRoutingMapper.<>c__DisplayClass2.<>c__DisplayClass4.<MapAttributeRoutes>b__1()
   at System.Web.Http.Routing.RouteCollectionRoute.EnsureInitialized(Func`1 initializer)
   at System.Web.Http.Routing.AttributeRoutingMapper.<>c__DisplayClass2.<MapAttributeRoutes>b__0(HttpConfiguration config)
   at System.Web.Http.CorsHttpConfigurationExtensions.<>c__DisplayClass3.<AddCorsMessageHandler>b__0(HttpConfiguration config)
   at System.Web.Http.HttpConfiguration.ApplyControllerSettings(HttpControllerSettings settings, HttpConfiguration configuration)
   at System.Web.Http.Controllers.HttpControllerDescriptor.InvokeAttributesOnControllerType(HttpControllerDescriptor controllerDescriptor, Type type)
   at Sitecore.Services.Infrastructure.Web.Http.Dispatcher.NamespaceHttpControllerSelector.InitializeControllerDictionary()
   at System.Lazy`1.CreateValue()
--- End of stack trace from previous location where exception was thrown ---
   at System.Lazy`1.get_Value()
   at Sitecore.Services.Infrastructure.Web.Http.Dispatcher.NamespaceHttpControllerSelector.SelectController(HttpRequestMessage request)
   at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"

在尝试升级时为我们工作。你应该完整阅读这篇文章以了解它在做什么，但简言之，你需要创建一个定制的HttpControllerSelector，并在Sitecore添加所有路由后将其与Sitecore交换。注：本摘要均不是我的。我从链接文章中收集了所有这些信息

---

作为补充说明，我强烈建议避免对Sitecore 8进行就地升级。我想说，使用新安装的Sitecore 8，然后通过软件包迁移您的内容几乎总是一个更好的选择。这是两种选择的绝佳选择

最好在回答中提供解决方案的摘要，请参阅我提供的两个链接的上下文。此外，我不会剽窃或窃取别人的作品。我们使用了那篇文章来解决问题，我不打算复制粘贴到这里。这对我来说很有效，但我需要添加以下内容：

public override IDictionary GetControllerMapping（）{return\u controllers；}

到

CustomHttpControllerSelector