完成相關(guān)數(shù)據(jù)服務(wù)

1、完成相關(guān)數(shù)據(jù)服務(wù)(correlot6d data service).在TruckService工程中，你會(huì)找到一個(gè)名稱為WorkflowTruckTrackingDatoService.cs的源文件。你需要翻開(kāi)它準(zhǔn)備進(jìn)行編輯。.第一件事是添加該服務(wù)執(zhí)行它的任務(wù)時(shí)所需要的私有字段。在WorkflowTruckTrackingDataService類的左大括號(hào)的后面添加下面這些代碼：private static WorkflowRuntime _workflowRuntime = null;private static ExternalDataExchangeService _dataExchan

2、geService = null;private static TruckServiceDataConnector _dataConnector = null;private static object _syncRoot = new object();.在這些私有字段的下面是該服務(wù)將觸發(fā)的事件。這些事件被觸發(fā)的結(jié)果就是工作流實(shí)例將調(diào)用一個(gè)CHExternolMethod 7制(你可在TruckServiceDotaConnector類中看至匕)：public event EventHandler TruckLeaving;public event EventHandler RouteUpda

3、ted;public event EventHandler TruckArrived;.接下來(lái)添加兩個(gè)字段以及對(duì)應(yīng)的屬性，你需要它們?nèi)?duì)相關(guān)的服務(wù)實(shí)例進(jìn)行識(shí)別: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 (_workflowRuntime = nu

4、ll)(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 data exc

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

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

7、syncRoot)WorkflowTruckTrackingDataService workflowDataService =TruckServiceDataConnector.GetRegisteredWorkflowDataService(instanceID, truckID);if (workflowDataService = null) workflowDataService = newWorkflowTruckTrackingDataService(instanceID, truckID);TruckServiceDataConnector.RegisterDataService(

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

9、)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 persisted workfl

10、ow 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.GetWorkflow(_ins

11、tanceID); / 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.GetWorkflow(_insta

12、nceID); / loads persisted workflowinstancesif (TruckArrived != null)TruckArrived(this, new TruckActivityEventArgs(_instanceIDz truckID);/ ifprivate Int32 _truckID = -1;public Int32 TruckIDget return _truckID; 5現(xiàn)在我們需要添加兩個(gè)靜態(tài)方法：一個(gè)是在工作流運(yùn)行時(shí)中注冊(cè)該服務(wù)并對(duì)它進(jìn)行配置,另一個(gè)是去對(duì)已經(jīng)注冊(cè)的服務(wù)實(shí)例進(jìn)行檢索：CreoteDataService 靜態(tài)方法和GMRegist

13、erdWorkflowDotoSrvic靜態(tài)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 were just

14、 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 dataConnector =(T

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

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

17、;if (workflowDataService = null)workflowDataService =new WorkflowTruckTrackingDataService(instanceID, truckID);TruckServiceDataConnector.RegisterDataService(workflowDataService);)return workflowDataService;.現(xiàn)在添加構(gòu)造器和析構(gòu)器:類的構(gòu)造器和析構(gòu)器代碼private WorkflowTruckTrackingDataService(Guid instancelD, Int32truckID

18、)this. instancelD = instancelD;this. truckID = truckID;WorkflowTruckTrackingDataService()/ Clean upworkflowRuntime = null;_dataExchangeService = null;dataConnector = null;備注：你可以回憶一下第8章，構(gòu)造器的作用是防止在服務(wù)和連接器類之間出現(xiàn)循環(huán) 鏈接引用。而對(duì)于析構(gòu)器的作用來(lái)說(shuō)，只是實(shí)現(xiàn)IDisposoble并不能完成相應(yīng)的任務(wù)，因?yàn)?當(dāng)從工作流運(yùn)行時(shí)中移除該服務(wù)的時(shí)候并不調(diào)用Dispose方法。.在類的構(gòu)造器的下面，添加下

19、面的讀取關(guān)聯(lián)數(shù)據(jù)的方法:public string Read() m .return _dataConnector.RetrieveTruckInfo(InstanceIDz TruckID);.最后添加事件實(shí)現(xiàn)的代碼：事件實(shí)現(xiàn)的代碼public void RaiseTruckLeavingEvent(Int32 truckID,Int32 starting/,Int32 startingY)if (_workflowRuntime = null)_workflowRuntime = new WorkflowRuntime();/ Loads persisted workflow instan

20、ces._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 instances._workf

21、lowRuntime.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 (TruckArrived != null)Tru

22、ckArrived(this, new TruckActivityEventArgs(_instanceID,truckID);/ if .保存該文件并編譯該TruckService工程。如果存在編譯錯(cuò)誤，請(qǐng)糾正任何出現(xiàn)的編 譯錯(cuò)誤。服務(wù)類的代碼就全部完成了，列表17-3展示了該類的完整代碼。TruckSercie本地通 信服務(wù)可以準(zhǔn)備使用了。我們還沒(méi)有一個(gè)工作流來(lái)使用該服務(wù)。我們也需要使用可信賴的 wca.exe工具來(lái)為我們創(chuàng)立自定義的CQllExtemolMethod和HandleExternalEvent活動(dòng)。列表 17-3 WorkflowTruckTrockingDcitciServicacs 的完整代碼WorkflowTruckTrackingDataService 類的完整代碼using System;using System.Collections.Generic;using System.Text;using System.Workflow.Activities;using System.Workflow.Runt