Question

我试图将此博客用于WCF RIA Applcation。所以我创建了一个Silverlight Nevigation Applciation，它给了我2个项目abs＆amp; abs.Web

更多我在解决方案中创建了3个项目：

abs.Data（c＃），DbContext实现存储库接口+工厂以提供用户想要的东西。
abs.Data.Contarct（c＃）操作存储库的接口
abs.Data.Model（c＃） - 包含POCO - EF 6

现在我在abs.Web项目中创建了一个wcf服务，该服务具有构建器注入存储库以在操作合同中完成我的工作。所以我尝试在下面的博客指南下使用Unity

http://jamesheppinstall.wordpress.com/2012/06/20/windows-communication-foundation-resolving-wcf-service-dependencies-with-unity/

现在我

提供的服务类型无法作为服务加载，因为它没有默认（无参数）构造函数。要解决此问题，请为该类型添加默认构造函数，或将该类型的实例传递给主机。

描述：在执行当前Web请求期间发生了未处理的异常。请查看堆栈跟踪以获取有关错误及其源自代码的位置的更多信息。

异常详细信息： System.InvalidOperationException：提供的服务类型无法作为服务加载，因为它没有默认（无参数）构造函数。要解决此问题，请在类型中添加默认构造函数，或将类型的实例传递给主机。

来源错误：

在执行当前Web请求期间生成了未处理的异常。可以使用下面的异常堆栈跟踪来识别有关异常的起源和位置的信息。

**堆栈追踪：**

[InvalidOperationException：提供的服务类型无法作为服务加载，因为它没有默认（无参数）构造函数。要解决此问题，请向该类型添加默认构造函数，或将该类型的实例传递给主机。]

  System.ServiceModel.Dispatcher.InstanceBehavior..ctor(DispatchRuntime dispatch, ImmutableDispatchRuntime immutableRuntime) +12761206
  System.ServiceModel.Dispatcher.ImmutableDispatchRuntime..ctor(DispatchRuntime dispatch) +173
 System.ServiceModel.Dispatcher.DispatchRuntime.GetRuntimeCore() +85
 System.ServiceModel.Dispatcher.ChannelDispatcher.OnOpened() +148
 System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout) +321
 System.ServiceModel.ServiceHostBase.OnOpen(TimeSpan timeout) +139
 System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout) +310
 System.ServiceModel.Channels.CommunicationObject.Open() +36
 System.ServiceModel.HostingManager.ActivateService(ServiceActivationInfo serviceActivationInfo, EventTraceActivity eventTraceActivity) +91
 System.ServiceModel.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath, EventTraceActivity eventTraceActivity) +598

[ServiceActivationException: The service '/DomainServices/UserWcfService.svc' cannot be activated due to an exception during compilation.  The exception message is: The service type provided could not be loaded as a service because it does not have a default (parameter-less) constructor. To fix the problem, add a default constructor to the type, or pass an instance of the type to the host..]
 System.Runtime.AsyncResult.End(IAsyncResult result) +499812
 System.ServiceModel.Activation.HostedHttpRequestAsyncResult.End(IAsyncResult result) +178
 System.ServiceModel.Activation.ServiceHttpHandler.EndProcessRequest(IAsyncResult result) +6
 System.Web.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar) +129




 Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET      Version:4.0.30319.18446

我的所有课程都与Blog一样。

Answer 1

WCF Ria拥有自己的工厂。
简单地说

public class MyDomainServiceFactory : IDomainServiceFactory
{

    #region IDomainServiceFactory Members

    public DomainService CreateDomainService(Type domainServiceType, DomainServiceContext context)
    {
        try
        {
            if (!typeof (DomainService).IsAssignableFrom(domainServiceType))
            {
                throw new ArgumentException(String.Format("Cannot create an instance of {0} since it does not inherit from DomainService", domainServiceType), "domainServiceType");
            }

            if (IoC.IsRegistered(domainServiceType))
            {

                var dmnService = (DomainService) IoC.Resolve(domainServiceType);
                dmnService.Initialize(context);
                return dmnService;
            }
            else
            {
                //if the IoC container doesn't know the service, simply try to call its default constructor
                //could throw proper exception as well
                var dmnService = (DomainService) Activator.CreateInstance(domainServiceType);
                dmnService.Initialize(context);
                return dmnService;
            }
        }
        catch (Exception ex)
        {
            ExceptionHandler.HandleException(ex);
            return null;
        }

    }


    public void ReleaseDomainService(DomainService domainService)
    {
        domainService.Dispose();
    }

    #endregion
}

以及引导代码中的某处添加

 DomainService.Factory = new MyDomainServiceFactory();

当然，工厂中的 IoC 一词标识了unityContainer（实际上是对它的静态外观）

使用Unity 3.5.1.0的WCF RIA服务

1 个答案: