完成相关数据服务.docx

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1、完成相关数据服务(correlot6d data service)1 .在TruckService工程中，你会找到一个名称为WorkflowTruckTrackingDatoService.cs的源文件。你需要翻开它准备进行编辑。2 .第一件事是添加该服务执行它的任务时所需要的私有字段。在WorkflowTruckTrackingDataService类的左大括号的后面添加下面这些代码：private static WorkflowRuntime _workflowRuntime = null;private static ExternalDataExchangeService _dataEx

2、changeService = null;private static TruckServiceDataConnector _dataConnector = null;private static object _syncRoot = new object();3 .在这些私有字段的下面是该服务将触发的事件。这些事件被触发的结果就是工作流实例将调用一个CHExternolMethod 7制(你可在TruckServiceDotaConnector类中看至匕)：public event EventHandler TruckLeaving;public event EventHandler Rou

3、teUpdated;public event EventHandler TruckArrived;4 .接下来添加两个字段以及对应的属性，你需要它们去对相关的服务实例进行识别:private Guid _instanceID = Guid.Empty;public Guid InstancelDget return JnstancelD; set _instanceID = value; lock (.syncRoot)/ If were just starting, save a copy of the workflow runtime reference if (_workflowRunt

4、ime = null)(workflowRuntime = workflowRuntime;/ if/ If were just starting, plug in ExternalDataExchange serviceif (_dataExchangeService = null) _dataExchangeService = new ExternalDataExchangeService();_workflowRuntime.AddService(_dataExchangeService);/ if/ Check to see if we have already added this

5、data exchange serviceTruckServiceDataConnector dataConnector =(TruckServiceDataConnector) workflowRuntime.GetService(typeof(TruckServiceDataCo nnector);if (dataConnector = null) _dataConnector = new TruckServiceDataConnector();_dataExchangeService.AddService(_dataConnector);)/ if elsedataConnector =

6、 dataConnector; / else / Pull the service instance we registered with the connection object returnWorkflowTruckTrackingDataService.GetRegisteredWorkflowDataService(instanceID,truckID); / lockpublic static WorkflowTruckTrackingDataServiceGetRegisteredWorkflowDataService(Guid instancelD, Int32 truckID

7、)lock (_syncRoot)WorkflowTruckTrackingDataService workflowDataService =TruckServiceDataConnector.GetRegisteredWorkflowDataService(instanceID, truckID);if (workflowDataService = null) workflowDataService = newWorkflowTruckTrackingDataService(instanceID, truckID);TruckServiceDataConnector.RegisterData

8、Service(workflowDataService);/ ifreturn workflowDataService; / lockprivate WorkflowTruckTrackingDataService(Guid instancelD, Int32truckID)this. instancelD = instancelD;this. truckID = truckID;WorkflowTruckTrackingDataService()/ Clean upworkflowRuntime = null;_dataExchangeService = null;dataConnector

9、 = null;)public string Read()return _dataConnector.RetrieveTruckInfo(InstanceID,TruckID);public void RaiseTruckLeavingEvent(Int32 truckID, Int32 starting/, Int32 startingY)if (_workflowRuntime = null)_workflowRuntime = new WorkflowRuntime();_workflowRuntime.GetWorkflow(_instanceID); / loads persiste

10、d workflow instancesif (TruckLeaving != null)TruckLeaving(this, new TruckActivityEventArgs(_instanceID, truckID, starting/, startingY);/ ifpublic void RaiseRouteUpdatedEvent(Int32 truckID, Int32 X, Int32 Y)if (_workflowRuntime = null)_workflowRuntime = new WorkflowRuntime();_workflowRuntime.GetWorkf

11、low(_instanceID); / loads persisted workflow instancesif (Routellpdated != null)Routellpdated(this, new TruckActivityEventArgs(_instanceID, truckID, X,/ ifpublic void RaiseTruckArrivedEvent(Int32 truckID)if (_workflowRuntime = null)_workflowRuntime = new WorkflowRuntime();_workflowRuntime.GetWorkflo

12、w(_instanceID); / loads persisted workflowinstancesif (TruckArrived != null)TruckArrived(this, new TruckActivityEventArgs(_instanceIDz truckID);/ ifprivate Int32 _truckID = -1;public Int32 TruckIDget return _truckID; 5现在我们需要添加两个静态方法：一个是在工作流运行时中注册该服务并对它进行配置,另一个是去对已经注册的服务实例进行检索：CreoteDataService 静态方法和

13、GMRegisterdWorkflowDotoSrvic静态方法public static WorkflowTruckTrackingDataServiceCreateDataService(Guid instancelD,WorkflowRuntime workflowRuntime,Int32 truckID)/ If were just starting, save a copy of the workflow./ runtime reference if (_workflowRuntime = null) workflowRuntime = workflowRuntime;/ If w

14、ere just starting, plug in ExternalDataExchange service.if (_dataExchangeService = null) _dataExchangeService = new ExternalDataExchangeService();_workflowRuntime.AddService(_dataExchangeService);)/ Check to see if we have already added this data/ exchange service.TruckServiceDataConnector dataConne

15、ctor =(TruckServiceDataConnector)workflowRuntime.GetService(typeof(T ruckServiceDataConnector);if (dataConnector = null) _dataConnector = new TruckServiceDataConnector();_dataExchangeService.AddService(_dataConnector); else dataConnector = dataConnector;)/ Pull the service instance we registered wit

16、h the connection / object.return WorkflowTruckTrackingDataService.GetRegisteredWorkflowDataService(instanceID, truckID);public static WorkflowTruckTrackingDataServiceGetRegisteredWorkflowDataService(Guid instancelD,Int32 truckID)TruckServiceDataConnector.GetRegisteredWorkflowDataService(instancelD,

17、truckID);if (workflowDataService = null)workflowDataService =new WorkflowTruckTrackingDataService(instanceID, truckID);TruckServiceDataConnector.RegisterDataService(workflowDataService);)return workflowDataService;6 .现在添加构造器和析构器:类的构造器和析构器代码private WorkflowTruckTrackingDataService(Guid instancelD, In

18、t32truckID)this. instancelD = instancelD;this. truckID = truckID;WorkflowTruckTrackingDataService()/ Clean upworkflowRuntime = null;_dataExchangeService = null;dataConnector = null;备注：你可以回忆一下第8章，构造器的作用是防止在服务和连接器类之间出现循环 链接引用。而对于析构器的作用来说，只是实现IDisposoble并不能完成相应的任务，因为 当从工作流运行时中移除该服务的时候并不调用Dispose方法。7 .在

19、类的构造器的下面，添加下面的读取关联数据的方法:public string Read() m .return _dataConnector.RetrieveTruckInfo(InstanceIDz TruckID);8 .最后添加事件实现的代码：事件实现的代码public void RaiseTruckLeavingEvent(Int32 truckID,Int32 starting/,Int32 startingY)if (_workflowRuntime = null)_workflowRuntime = new WorkflowRuntime();/ Loads persisted w

20、orkflow instances._workflowRuntime.GetWorkflow(_instanceID);if (TruckLeaving != null)耳TruckLeaving(this, new TruckActivityEventArgs(_instanceID, truckID, starting/, startingY);/ ifpublic void RaiseRoutellpdatedEvent(Int32 truckID,_workflowRuntime = new WorkflowRuntime();/ Loads persisted workflow in

21、stances._workflowRuntime.GetWorkflow(_instanceID);if (Routellpdated != null)truckID,X, Y);public void RaiseTruckArrivedEvent(Int32 truckID)if (_workflowRuntime = null)_workflowRuntime = new WorkflowRuntime(); Loads persisted workflow instances._workflowRuntime.GetWorkflow(_instanceID);if (TruckArriv

22、ed != null)TruckArrived(this, new TruckActivityEventArgs(_instanceID,truckID);/ if 9 .保存该文件并编译该TruckService工程。如果存在编译错误，请纠正任何出现的编 译错误。服务类的代码就全部完成了，列表17-3展示了该类的完整代码。TruckSercie本地通 信服务可以准备使用了。我们还没有一个工作流来使用该服务。我们也需要使用可信赖的 wca.exe工具来为我们创立自定义的CQllExtemolMethod和HandleExternalEvent活动。列表 17-3 WorkflowTruckTr

23、ockingDcitciServicacs 的完整代码WorkflowTruckTrackingDataService 类的完整代码using System;using System.Collections.Generic;using System.Text;using System.Workflow.Activities;using System.Workflow.Runtime;namespace TruckServicepublic class WorkflowTruckTrackingDataServiceprivate static WorkflowRuntime _workflow

24、Runtime = null;private static ExternalDataExchangeService _dataExchangeService = null;private static TruckServiceDataConnector _dataConnector = null;private static object _syncRoot = new object();public event EventHandler TruckLeaving;public event EventHandler RouteUpdated;public event EventHandler

25、TruckArrived;private Guid _instanceID = Guid.Empty;public Guid InstancelDget return JnstancelD; set JnstancelD = value; )private Int32 _truckID = -1;public Int32 TruckIDget return _truckID; set _truckID = value; )public static WorkflowTruckTrackingDataService CreateDataService(GuidinstancelD, WorkflowRuntime workflowRuntime, Int32 truckID)