使用WCF和Autofac的自定义端点行为

Question

我正在尝试实现如下所示的UoW:http://blog.iannelson.systems/wcf-global-exception-handling/

但我不能为我的生活弄清楚如何用Autofac连接它.我完全不知道从哪里开始.

使用http://autofac.readthedocs.org/en/latest/integration/wcf.html我使用Autofac让WCF正常工作

但要注入或添加IEndpointBehavior？不知道...

如果有更好的方法来实现UoW,我想听听.

编辑:

现在我刚刚完成了:

builder.RegisterType(typeof (UnitOfWork))
    .As(typeof (IUnitOfWork))
    .InstancePerLifetimeScope()
    .OnRelease(x =>
    {
        Trace.WriteLine("Comitted of UoW");
        ((IUnitOfWork) x).Commit();
        // OnRelease inhibits the default Autofac Auto-Dispose behavior so explicitly chain to it
        x.Dispose(); 
    });

虽然我不知道这是否是一种可以接受的方式,但看起来像是黑客:(

EDIT2:

似乎不可能在WCF中运行UoW:/

编辑3:

我在这里发布了我的解决方案:http://www.philliphaydon.com/2011/11/06/unit-of-work-with-wcf-and-autofac/

Answer 1

我找到了解决这个问题的方法，只有在没有抛出错误的情况下才会提交工作单元。

在 Autofac 中将工作单元注册为 InstancePerLifetimeScope

    builder.RegisterType(typeof (UnitOfWork))
    .As(typeof (IUnitOfWork)).InstancePerLifetimeScope();

然后我创建了一个组合的 EndpointBehavior 和 ErrorHandler。

public class UnitOfWorkEndpointBehavior : BehaviorExtensionElement, IEndpointBehavior
{
    public void Validate(ServiceEndpoint endpoint)
    {
    }

    public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters)
    {
    }

    public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
    {
        var unitOfWorkInstanceHandler = new UnitOfWorkInstanceHandler();

        endpointDispatcher.ChannelDispatcher.ErrorHandlers.Add(unitOfWorkInstanceHandler);
        endpointDispatcher.DispatchRuntime.InstanceContextInitializers.Add(unitOfWorkInstanceHandler);
    }

    public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)
    {
    }

    protected override object CreateBehavior()
    {
        return new UnitOfWorkEndpointBehavior();
    }

    public override Type BehaviorType
    {
        get { return typeof (UnitOfWorkEndpointBehavior); }
    }
}



public class UnitOfWorkInstanceHandler : IInstanceContextInitializer, IErrorHandler
{
    private bool _doCommit = true;

    public void Initialize(InstanceContext instanceContext, Message message)
    {
        instanceContext.Closing += CommitUnitOfWork;
    }

    void CommitUnitOfWork(object sender, EventArgs e)
    {
        //Only commit if no error has occured
        if (_doCommit)
        {
            //Resolve the UnitOfWork form scope in Autofac
            OperationContext.Current.InstanceContext.Extensions.Find<AutofacInstanceContext>().Resolve<IUnitOfWork>().Commit();
        }
    }

    public void ProvideFault(Exception error, MessageVersion version, ref Message fault)
    {
        _doCommit = false;
    }

    public bool HandleError(Exception error)
    {
        _doCommit = false;
        return false;
    }
}

web.config 中端点行为的注册

<system.serviceModel>
    ...
    <extensions>
      <behaviorExtensions>
        <add name="UnitOfWork" type="Namespace.UnitOfWorkBehavior, Namespace"/>
      </behaviorExtensions>
    </extensions>
      <behaviors>
        <endpointBehaviors>
          <behavior name="">
            <UnitOfWork/>
          </behavior>
        </endpointBehaviors>
    ...
    </behaviors>
    ...
</system.serviceModel>