Question

大家都在向WorkflowServiceHost添加自定义行为时遇到问题。

这是我的WorflowServiceHostFactory：

public class ScoringWorkflowServiceHostFactory : WorkflowServiceHostFactory, IServiceHost<IKernel>
{
    private static IKernel _InjectionInstance;
    public IKernel InjectionInstance
    {
        get { return _InjectionInstance ?? (_InjectionInstance = new StandardKernel(new ScoringWorkflowServicesNinjectModule(Scope))); }
    }

    public object Scope
    {
       get { return Guid.NewGuid(); }      
    }

    public override ServiceHostBase CreateServiceHost(string constructorString, Uri[] baseAddresses)
    {

        String fullFilePath = Path.Combine(HostingEnvironment.ApplicationPhysicalPath, constructorString);

        WorkflowService wf = CSharpExpressionCompiler.Compile(fullFilePath);

        System.ServiceModel.Activities.WorkflowServiceHost host = base.CreateWorkflowServiceHost(wf, baseAddresses);


        NinjectBehaviorAttributeWF behavior = new NinjectBehaviorAttributeWF(wf);

        host.Description.Behaviors.Add(behavior);

        host.AddNinjectResolverExtension(InjectionInstance, Scope);

        TypeAdapterFactory.SetCurrent(new SvcMapperAdapterFactory());

        LoggerFactory.SetCurrent(new EntLibLoggerFactory());

        return host;
    }

}

这是我的行为：

public class NinjectBehaviorAttributeWF : Attribute, IServiceBehavior
{
private System.ServiceModel.Activities.WorkflowService host;

public NinjectBehaviorAttributeWF(System.ServiceModel.Activities.WorkflowService host)
{

    this.host = host;
}
    public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, Collection<ServiceEndpoint> endpoints, BindingParameterCollection bindingParameters)
    {
    }

    public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {

        foreach (ChannelDispatcher dispatcher in serviceHostBase.ChannelDispatchers)
        {
            foreach (EndpointDispatcher endpointDispatcher in dispatcher.Endpoints)
            {
                DispatchRuntime dispatchRuntime = endpointDispatcher.DispatchRuntime;

                dispatchRuntime.InstanceContextProvider = new PerCallInstanceContextProvider(dispatchRuntime);
            }
        }
    }

    public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
    }
}

这样，我在加载服务时遇到错误（xamlx）：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。

我不知道它是否可能，也不知道如何为工作流服务创建默认构造函数（因为真正的实现是xamlx而不是简单的类）

所以，我尝试过使用自定义提供程序：

 dispatchRuntime.InstanceProvider = new CustomInstanceProvider(host.Body);

CustomInstanceProvider是：

public class CustomInstanceProvider : IInstanceProvider
{
string message;
private System.Activities.Activity activity;

public CustomInstanceProvider(string msg)
{
Console.WriteLine("The non-default constructor has been called.");
this.message = msg;

}

public CustomInstanceProvider(System.Activities.Activity activity)
{
  this.activity = activity;
}

public object GetInstance(InstanceContext instanceContext,   System.ServiceModel.Channels.Message message)
{
Console.WriteLine("GetInstance is called:");
return this.activity;
}

public object GetInstance(InstanceContext instanceContext)
{
  Console.WriteLine("GetInstance is called:");
  return this.activity;
}

public void ReleaseInstance(InstanceContext instanceContext, object instance)
{
Console.WriteLine("ReleaseInstance is called");
}
}

但我有这个错误：

System.InvalidCastException: Unable to cast object of type 'System.ServiceModel.Activities.WorkflowService' to type 'IHttpGetMetadata'.

如何解决我的问题？非常感谢

将行为属性添加到WorkflowServiceHost

0 个答案: