Question

我尝试使用Autofac 3.1.0配置我的Web API服务。

我已添加＆＃34;标记＆＃34;属性到控制器：

[AutofacControllerConfiguration]
public class DocumentController : ApiController
{
    // ... snip ...
}

并注册了它：

// controllers
container.RegisterApiControllers(typeof (DocumentController).Assembly);
container.RegisterApiControllers(typeof (WorkflowController).Assembly);

// security
container.RegisterType<OAuthTokenManager>().As<IOAuthTokenManager>();
container.RegisterType<OAuthAccessToken>().As<IOAuthAccessToken>();
container.RegisterType<LegacyTypeAwareIdentifierFactory<IOAuthAccessToken>>().As<ITypeAwareIdentifierFactory<IOAuthAccessToken>>();
container.RegisterType<OAuthTokenExtractor>().As<ITokenExtractor>();
container.RegisterType<OAuthTokenValidator>().As<ITokenValidator>();
container.RegisterType<TokenHelper>().As<ITokenHelper>();

container.Register(x =>
{
    if (x.IsRegistered<HttpRequestMessage>())
    {
        var httpRequestMethod = x.Resolve<HttpRequestMessage>();

        var tokenHelper = x.Resolve<ITokenHelper>();
        var token = tokenHelper.GetToken(httpRequestMethod);

        var connectionContext = x.Resolve<ISqlServerConnectionContext>();
        connectionContext.Token = token;

        return token ?? new NullMinimalSecurityToken();
    }

    return new NullMinimalSecurityToken();
}).As<IMinimalSecurityToken>().InstancePerApiRequest();

container.RegisterType<SecurityTokenAuthorization>()
    .AsWebApiAuthorizationFilterFor<DocumentController>()
    .InstancePerApiRequest();
container.RegisterType<SecurityTokenAuthorization>()
    .AsWebApiAuthorizationFilterFor<WorkflowController>()
    .InstancePerApiRequest();

container.Register(c =>
{
    var connectionString = ConfigurationManager.AppSettings[AppSettingsNames.DatabaseConnection];
    var newConnectionContext = new SqlServerConnectionContext(connectionString) {ProductID = productId};
    newConnectionContext.Open();

    return newConnectionContext;
    }).As<ISqlServerConnectionContext>().As<IConnectionContext>().InstancePerApiRequest().InstancePerApiControllerType(typeof(DocumentController));

我最终得到以下错误：

{
"Message":"An error has occurred.",
"ExceptionMessage":"Object reference not set to an instance of an object.",
"ExceptionType":"System.NullReferenceException",
"StackTrace":"   at System.Web.Http.Tracing.Tracers.HttpControllerDescriptorTracer.get_Properties()\r\n   at Autofac.Integration.WebApi.AutofacControllerConfigurationAttribute.Initialize(HttpControllerSettings controllerSettings, HttpControllerDescriptor controllerDescriptor)\r\n   at System.Web.Http.Controllers.HttpControllerDescriptor.InvokeAttributesOnControllerType(HttpControllerDescriptor controllerDescriptor, Type type)\r\n   at System.Web.Http.Controllers.HttpControllerDescriptor..ctor(HttpConfiguration configuration, String controllerName, Type controllerType)\r\n   at System.Web.Http.Tracing.Tracers.HttpControllerSelectorTracer.System.Web.Http.Dispatcher.IHttpControllerSelector.SelectController(HttpRequestMessage request)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsyncInternal(HttpRequestMessage request, CancellationToken cancellationToken)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)"
}

如果我只是删除＆＃34;标记＆＃34;属性，我的服务工作，但这不是一个可行的解决方案，因为我有2个控制器，需要为每个控制器提供正确的数据库连接。我很乐意实施一个替代解决方案，但是在为了达到这一点一整天的努力之后，我现在正在画一个空白。

我是否错过了使用该功能的内容，或者有人可以提出替代方案？

Autofac AutofacControllerConfiguration因HttpControllerDescriptorTracer null引用异常而失败

0 个答案: