.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 try 32 { 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 try 10 { 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 IWorkflowMethods 2 { 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 else 47 { 48 throw new WorkFlowAuditPersonNotFoundException("没有找到审核对象！"); 49 } 50 return persons; 51 }