之前，我通过4篇文章介绍了在WF4中开发基于事件的工作流的范例。请参考下面的链接。
这一篇是这个系列的最后一篇，介绍如何通过配置文件，而不是代码的方式启动宿主。这在现实工作中是相当有用的，请大家参考下面的实例。
【注意】有朋友也问到单独用数据库存储业务方面的数据，那是没有错的。一般可以通过自定义的Activity去完成这些操作，都是标准的ADO.NET的数据访问操作。这里就不做展开了。
这个案例的最终代码范例，请通过 这里 下载
1.修改之前的Host代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;
using System.Activities;
using System.ServiceModel.Activities;
using System.ServiceModel.Description;using System.Activities.DurableInstancing;
using System.Runtime.DurableInstancing;
using System.Activities.Persistence;
using System.ServiceModel.Activities.Description;
using System.Xml.Linq;namespace Host
{class Program{static void Main(string[] args){var host = new WorkflowServiceHost(new DocumentReviewLib.DocumentReviewWorkflow(),new Uri("http://localhost:8080/DRS"));host.AddDefaultEndpoints();//这个方法是添加了一些标准的端点host.Description.Behaviors.Add(new ServiceMetadataBehavior() { HttpGetEnabled = true });var store = new SqlWorkflowInstanceStore("server=(local)\\sqlexpress;database=WF4;integrated security=true");host.UnknownMessageReceived += (o, e) =>{Console.WriteLine("\n" + e.Message + "\n");};host.Description.Behaviors.Add(new WorkflowIdleBehavior(){TimeToPersist = TimeSpan.FromSeconds(0)});XNamespace xNS = XNamespace.Get("http://xizhang.com/DocumentReview");store.Promote("DocumentReview",new List<XName>() { xNS.GetName("TicketId") },null);host.WorkflowExtensions.Add(new Extensions.MyInstanceStoreParticpant());host.DurableInstancingOptions.InstanceStore = store;host.Open();var common = new ServiceHost(typeof(CommonService),new Uri("http://localhost:8080/Common"));common.AddServiceEndpoint(typeof(ICommonService).FullName,new BasicHttpBinding(),"");common.Open();Console.WriteLine("Server is ready.");Console.Read();}}[ServiceContract]public interface ICommonService{[OperationContract]int[] GetTicketIds();}public class CommonService : ICommonService{public int[] GetTicketIds(){var ctx = new InstanceStoreDataContext();return ctx.DocumentReviewTasks.Select(r => (int)r.TicketId).ToArray();}}}
2. 修改之后的Host代码（请大家比较一下有何区别）
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;
using System.Activities;
using System.ServiceModel.Activities;
using System.ServiceModel.Description;using System.Activities.DurableInstancing;
using System.Runtime.DurableInstancing;
using System.Activities.Persistence;
using System.ServiceModel.Activities.Description;
using System.Xml.Linq;namespace Host
{class Program{static void Main(string[] args){var host = new WorkflowServiceHost(new WorkflowService() { ConfigurationName = "DocumentReviewLib.DocumentReviewWorkflow",Body = new DocumentReviewLib.DocumentReviewWorkflow()});//这里可以通过进一步的Behavior定制来简化。此处略 XNamespace xNS = XNamespace.Get("http://xizhang.com/DocumentReview");var store = (SqlWorkflowInstanceStoreBehavior)host.Description.Behaviors.FirstOrDefault(b => b.GetType() == typeof(SqlWorkflowInstanceStoreBehavior));store.Promote("DocumentReview",new List<XName>() { xNS.GetName("TicketId") },null);//这里可以通过进一步的Behavior定制来简化。此处略host.WorkflowExtensions.Add(new Extensions.MyInstanceStoreParticpant());host.Open();var common = new ServiceHost(typeof(CommonService));common.Open();Console.WriteLine("Server is ready.");Console.Read();}}[ServiceContract]public interface ICommonService{[OperationContract]int[] GetTicketIds();}public class CommonService : ICommonService{public int[] GetTicketIds(){var ctx = new InstanceStoreDataContext();return ctx.DocumentReviewTasks.Select(r => (int)r.TicketId).ToArray();}}}
3.添加的app.config文件内容
<?xml version="1.0" encoding="utf-8" ?>
<configuration><configSections></configSections><connectionStrings><add name="Host.Properties.Settings.WF4ConnectionString" connectionString="Data Source=.\sqlexpress;Initial Catalog=WF4;Integrated Security=True"providerName="System.Data.SqlClient" /></connectionStrings><system.serviceModel><behaviors><serviceBehaviors><behavior name="WorkflowService"><sqlWorkflowInstanceStore connectionStringName="Host.Properties.Settings.WF4ConnectionString"/><workflowIdle timeToPersist="0" timeToUnload="0"/><serviceMetadata httpGetEnabled="true"/></behavior></serviceBehaviors></behaviors><services><service name="DocumentReviewLib.DocumentReviewWorkflow" behaviorConfiguration="WorkflowService"><host><baseAddresses><add baseAddress="http://localhost:8080/DRS"/></baseAddresses></host><endpoint contract="IDocumentReview" address="" binding="basicHttpBinding"></endpoint></service><service name="Host.CommonService"><host><baseAddresses><add baseAddress="http://localhost:8080/Common"/></baseAddresses></host><endpoint contract="Host.ICommonService" binding="basicHttpBinding" address=""></endpoint></service></services></system.serviceModel></configuration> 这个案例的最终代码范例，请通过 下载
)
)