Workflow Foundation 4.0中的事件驱动流程设计和应用（五）

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。

Workflow Foundation 4.0中的事件驱动流程设计和应用（一）

Workflow Foundation 4.0中的事件驱动流程设计和应用（二）

Workflow Foundation 4.0中的事件驱动流程设计和应用（三）

Workflow Foundation 4.0中的事件驱动流程设计和应用（四）

 

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
  
   () { 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
  
   () { 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

  "1.0" encoding="utf-8" ?>

  
    
    
   
    
    
    
     "Host.Properties.Settings.WF4ConnectionString" connectionString=
     "Data Source=./sqlexpress;Initial Catalog=WF4;Integrated Security=True" providerName=
     "System.Data.SqlClient" /> 
    
   
  
    
     
      
      
       "WorkflowService"> 
       
        "Host.Properties.Settings.WF4ConnectionString"/> 
        
         "0" timeToUnload=
         "0"/> 
         
          "true"/> 
         
        
       
       
      
     
     
     
      "DocumentReviewLib.DocumentReviewWorkflow" behaviorConfiguration=
      "WorkflowService"> 
       
        
        
         "http://localhost:8080/DRS"/> 
        
        
       
      
       "IDocumentReview" address=
       "" binding=
       "basicHttpBinding">
       
      
     
      "Host.CommonService"> 
       
        
        
         "http://localhost:8080/Common"/> 
        
        
       
      
       "Host.ICommonService" binding=
       "basicHttpBinding" address=
       "">
       
      
     
   
  

  

这个案例的最终代码范例，请通过 这里 下载