.net之工作流工程展示及代码分享（四）主控制类

现在应该讲主控制类了，为了不把系统弄得太复杂，所以就用一个类作为主要控制类（服务类），作为前端、后端、业务逻辑的控制类。

WorkflowService类的类图如下：

该类的构造函数：

1         public WorkflowService(IWorkflowDB workflowDb, IWorkflowMethods workflowMethods)2         {3             _iWorkflowDb = workflowDb;4             _iWorkflowMethods = workflowMethods;5         }

通过简单工厂方法返回类的实例：

 1         /// <summary> 2         /// 程序主调用方法 3         /// </summary> 4         /// <returns></returns> 5         public static WorkflowService GetWorkflowService() 6         { 7             IWorkflowDB iWorkflowDb; 8             try 9             {10             string dbSavingPRovider = WorkFlowUtility.GetConfiguration("DataBaseProvider").ToLower();11                 switch (dbSavingProvider)12                 {13                     case "Oracle":14                         iWorkflowDb = new OracleWorkFlowDBUtility();15                         break;16                     case "sqlserver":17                         //iWorkflowDb = new SqlServerWorkFlowDBUtility();18                         //break;19                     default:20                         iWorkflowDb = (IWorkflowDB) Assembly.Load(dbSavingProvider).CreateInstance(dbSavingProvider);21                         break;22                 }23 24             }25             catch (Exception)26             {27                 throw new WorkFlowConfigurationNotImplementException("数据库配置失败！");28             }29 30                 IWorkflowMethods iWorkflowMethods;31             try32             {33                 string dbInterface = WorkFlowUtility.GetConfiguration("WorkflowConfigurationNameSpace");34                 iWorkflowMethods = (IWorkflowMethods)Assembly.Load(dbInterface).CreateInstance(dbInterface + ".WorkflowConfiguration");35             }36             catch (Exception ex)37             {38                 throw new WorkFlowConfigurationNotImplementException("应用程序实例配置失败！");39             }40 41             return new WorkflowService(iWorkflowDb, iWorkflowMethods);42         }

所有方法返回的类型都是WorkflowServiceResponse类型，该类定义如下：

 1     public class WorkflowServiceResponse 2     { 3         public WorkflowServiceResponse() 4         { 5             Success = false; 6         } 7         public bool Success { get; set; }  8         public string Message { get; set; } 9         public dynamic ReturnEntity { get; set; }10     }

使用了Request-Response模式，其中返回的实体使用了.net4.0新增的Dynamic类型，这样就不用做抽象类，然后各种不同的返回类型来继承基类了。

调用的方法如下：

1             var wfs = WorkflowService.GetWorkflowService();2             var wfsr = wfs.GetFlowById(flowId);3             if (!wfsr.Success)4             {5                 this.ShowAndRedirects("参数错误", "FlowManager.aspx");6                 return;7             }8             var flow = wfsr.ReturnEntity as Flow;9 .......

那GetFlowById是怎么写的呢？

 1         /// <summary> 2         /// 根据流程Id得到一个流程的情况 3         /// </summary> 4         /// <param name="flowId"></param> 5         /// <returns></returns> 6         public WorkflowServiceResponse GetFlowById(Guid flowId) 7         { 8             var wfsr = new WorkflowServiceResponse(); 9             try10             {11                 var flow = _iWorkflowDb.GetFlows().SingleOrDefault(f => f.FlowId == flowId);12                 if (flow != null)13                 {14                     wfsr.ReturnEntity = flow;15                     wfsr.Success = true;16                 }17             }18             catch (Exception ex)19             {20                 wfsr.Message = ex.ToString();21             }22             return wfsr;23         }

这样前后端都串起来了。

在IWorkflowDB接口定义里，GetFlows返回的是List<Flow>对象，所以这么做数据接口存在一定的性能问题，如果改成IQueryable<Flow>就能够返回Linq表达式，实现Lazy-Loaing的模式，但是Oracle不支持Linq查询，以后换EF看看......

大家注意到了WorkflowService类里面还有个IWorkflowMethods接口。对了，这个接口就是和其它系统交互的关键，定义如下：

1     public interface IWorkflowMethods2     {3         Person GetCurrentLoginPerson();4         IList<Person> GetPersonByCondition(SearchCriteria searchCriteria);5         bool SendMail(Person person, string message);6         bool SendMessage(Person person, string message);7         string GetAutoCompleteValueByType(string autoCompleteType);8         IList<string> GetUserRoleGroupNames(Person person);9     }

这些方法分别是获取当前登录用户、根据条件获取应该审核流程的用户、调用原系统方法法邮件、发短信，用于表单处理中的自动填入用户姓名、职务等，获取用户所在的组（有些流程只有特定组可以申请）。

在其中一个系统中的实现方法如下：

 1         public IList<Person> GetPersonByCondition(SearchCriteria searchCriteria) 2         { 3             var flowLaunchPerson = searchCriteria.FlowLaunchPerson; 4             string sql = string.Empty; 5             IList<Person> persons = new List<Person>(); 6             switch (searchCriteria.NextPersonWorkGroupName) 7             { 8                 case ".....": 9                     break;10                 case "xxx审核":11                 {12                     sql = string.Format(" jsgh in (select gh from VM_TUAN....ERGR where zbid in" +13                                         " (select zbid from TUA....ELATIONSHip where gh = '{0}' or xh = '{0}')" +14                                         " and lv = 4 and zwname = '辅导员）')  ", flowLaunchPerson.PersonId);15                     break;16                 }17                 case ".....审核":18                 {19                     sql = string.Format(" jsgh in (select gh from VM.....HERGR where zbid in" +20                                         " (select zbid from TUA....IONSHIP where gh = '{0}' or xh = '{0}')" +21                                         " and lv = 4 and zwname = '...')  ", flowLaunchPerson.PersonId); 22                     break;23                 };24                  case ".....审核":25                   ........26                   break;27                 default:28                     break;29             }30 31             var teachers = new B.....GetModelList(sql);32 33             if (teachers.Count > 0)34             {35                 foreach (var teacher in teachers)36                 {37                     Person person = new Person()38                     {39                         PersonId = teacher.....,40                         PersonName = teacher.J....,41                         PersonEmail = teacher.E....,42                     };43                     persons.Add(person);44                 }45             }46             else47             {48                 throw new WorkFlowAuditPersonNotFoundException("没有找到审核对象！");49             }50             return persons;51         }

最后分享服务类中两个核心的方法

新建流程：

 1         /// <summary> 2         /// 根据流程Id建立新的流程 3         /// </summary> 4         /// <param name="workflowAddStepParameter"></param> 5