很多初学者，首先最想解决的问题是：如何将WF与MVC程序相结合。由于Web程序属于长时间运行的流程，因此持续化功能的运用就非常重要了。
本文将结合书签、WorkflowApplication、生命周期事件、MVC、持续化、传参、状态机实现一个简单的审核流程的示例。
本文模拟一个用户注册流程，此流程非常简单，简单到什么地步？
两个用户，版主与管理员，版主负责帮助录入新用户信息，但需要管理员审核通过后才插入数据库，否则审核不通过回退给版主修改。
首先设计一张表如下：
真实环境中不应该这样设计，而是外键关联用户数据(Id、Name、PassWord、Age)，本处作为Demo，一切从简。
首先设计一个流程如下：
流程并不复杂，此处需要3个"活动类"，"一个书签类"。如"提交"活动类代码：
public sealed class Upload : CodeActivity
{
public InOutArgument<WorkflowModel> workflowModel { get; set; }
protected override void Execute(CodeActivityContext context)
{
WorkflowModel model = context.GetValue<WorkflowModel>(workflowModel);
model.WorkflowId = context.WorkflowInstanceId;
model.State = "等待审核";
try
{
model.Add(); //插入数据库
}
catch(Exception e)
{
Console.WriteLine(e.Message);
}
}
}
其放在"提交"State里。
公用书签代码如下：
public sealed class CustomBookmark : NativeActivity
{
public InArgument<string> BMName { get; set; }
public InOutArgument<WorkflowModel> workflowModel { get; set; }
protected override bool CanInduceIdle { get { return true; } }
protected override void Execute(NativeActivityContext context)
{
string BookMarkName = context.GetValue<string>(BMName);
context.CreateBookmark(BookMarkName, new BookmarkCallback(borkmarkCallback));
}
void borkmarkCallback(NativeActivityContext context, Bookmark bookmark, object obj)
{
Dictionary<string, object> Dic = obj as Dictionary<string, object>;
context.SetValue(workflowModel, Dic["Model"] as WorkflowModel);
}
}
其放在“状态切换线”上，如回退书签：
整个工作流仅仅一个参数，上面那张表的一个实体：
此参数，也作为全局变量使用了。
如果在MVC的Controller里面的Action里面操作工作流的话，代码会非常的乱。所以另外起了一个工作流帮助类。
核心类
其代码如下：
public class WorkflowHelper
{
#region 工作流属性 WorkflowApplication instance = null;
SqlWorkflowInstanceStore instanceStore = null;
InstanceView view;
AutoResetEvent idleEvent = new AutoResetEvent(false); #endregion //初始化工作流
public void InitialWorkflowApplication()
{
string connectionString = "server=192.168.0.69;database=waterageII;uid=water;pwd=water";
instance.Idle = delegate(WorkflowApplicationIdleEventArgs e)
{
idleEvent.Set();
};
instance.Completed = delegate(WorkflowApplicationCompletedEventArgs e)
{
idleEvent.Set();
};
instanceStore = new SqlWorkflowInstanceStore(connectionString);
view = instanceStore.Execute(instanceStore.CreateInstanceHandle(), new CreateWorkflowOwnerCommand(), TimeSpan.FromSeconds());
instanceStore.DefaultInstanceOwner = view.InstanceOwner;
instance.InstanceStore = instanceStore;
} public string Next(WorkflowModel model)
{
if (model.Id <= )
{
Dictionary<string, object> Dic = new Dictionary<string, object>();
Dic.Add("Model", model);
instance = new WorkflowApplication(new Register(), Dic);
InitialWorkflowApplication();
instance.Run();
}
else
{
instance = new WorkflowApplication(new Register());
InitialWorkflowApplication();
instance.Load(model.WorkflowId);
if (instance.GetBookmarks().Count() > )
{
Dictionary<string, object> Dic = new Dictionary<string, object>();
Dic.Add("Model", model);
BookmarkResumptionResult BRR = instance.ResumeBookmark("Bookmark", Dic);
}
}
//等待工作流线程空闲，才往下走
idleEvent.WaitOne();
instance.Unload();
return "运行成功";
}
public WorkflowModel GetModelById(int Id)
{
WorkflowModel w = new WorkflowModel();
DataTable dt = w.Get(Id);
WorkflowModel model = new WorkflowModel();
if (dt != null)
{
DataRow dr = dt.Rows[];
model.Id = Convert.ToInt32(dr["Id"]);
model.Name = Convert.ToString(dr["Name"]);
model.PassWord = Convert.ToString(dr["PassWord"]);
model.Age = Convert.ToInt32(dr["Age"]);
model.State = Convert.ToString(dr["State"]);
model.BelongUser = Convert.ToString(dr["BelongUser"]);
model.OperateUser = Convert.ToString(dr["OperateUser"]);
model.OperateTime = Convert.ToDateTime(dr["OperateTime"]);
model.OperateType = Convert.ToString(dr["OperateType"]);
model.WorkflowId = new Guid(Convert.ToString(dr["WorkflowId"]));
return model;
}
return null;
}
}
这样一封装了之后，MVC的Controller非常简洁：
public class HomeController : Controller
{
User Manager = new User() { Name = "管理员" };
User NewUser = new User() { Name = "版主" }; [HttpGet]
public ActionResult Login()
{
return View();
} [HttpPost]
public ActionResult Login(string UserName)
{
Session["UserName"] = UserName;
return Redirect("/Home/List");
} public ActionResult List()
{
//管理员列表，能看到"等待审核"的数据，而版主能看到"审核回退"的数据
string State = Session["UserName"].ToString() == "管理员" ? "等待审核" : "审核回退";
WorkflowModel model = new WorkflowModel();
DataTable dt = model.GetNewestByState(State);
return View(dt);
} public ActionResult Register()
{
return View();
} public ActionResult Upload(WorkflowModel model)
{
model.OperateUser = Session["UserName"].ToString();
model.OperateTime = DateTime.Now;
model.OperateType = "提交"; WorkflowHelper WFController = new WorkflowHelper();
WFController.Next(model); return Content("提交成功，请等待管理员审核!");
} [HttpGet]
public ActionResult Check(int Id)
{
WorkflowHelper WFController = new WorkflowHelper();
WorkflowModel model = WFController.GetModelById(Id);
return View(model);
} [HttpPost]
public ActionResult Check(WorkflowModel model)
{
model.OperateUser = Session["UserName"].ToString();
model.OperateTime = DateTime.Now;
model.OperateType = "审核"; //审核(调用控制器的审核方法)
WorkflowHelper WFController = new WorkflowHelper();
string response = WFController.Next(model); return Content(response);
} public ActionResult Return(int Id)
{
WorkflowHelper WFController = new WorkflowHelper();
WorkflowModel model = WFController.GetModelById(Id);
return View(model);
}
}
Controller就只做一件事，拿数据，调用流程控制器的方法(无论当前是在哪一步，都只管调用Helper类的Next()方法，我用了多个页面，相对来说，一个页面一个比较好，因为会涉及到权限以及下一步的角色与用户)，所有流程的初始化，流程走到哪一步了，是否已经持续化，能不能加载出来，在Controller里面都不用管。
实体层(在里面包含了数据库访问)如下：
public class WorkflowModel
{
static string ConstringSql = "server=CZZ;database=xxoo;uid=sa;pwd=123;";
public int Id { get; set; }
public string Name { get; set; }
public string PassWord { get; set; }
public int Age { get; set; }
public string Option { get; set; }
public string State { get; set; }
public string BelongUser { get; set; }
public string OperateUser { get; set; }
public DateTime OperateTime { get; set; }
public string OperateType { get; set; }
public Guid WorkflowId { get; set; } public void Add()
{
SqlConnection conn = new SqlConnection(ConstringSql);
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "INSERT INTO WorkflowRegister VALUES(@Name,@PassWord,@Age,@Option,@State,@BelongUser,@OperateUser,@OperateTime,@OperateType,@WorkflowId)";
//设置参数类型
cmd.Parameters.Add("@Name", SqlDbType.NVarChar);
cmd.Parameters.Add("@PassWord", SqlDbType.VarChar);
cmd.Parameters.Add("@Age", SqlDbType.Int);
cmd.Parameters.Add("@Option", SqlDbType.NVarChar);
cmd.Parameters.Add("@State", SqlDbType.NVarChar);
cmd.Parameters.Add("@BelongUser", SqlDbType.NVarChar);
cmd.Parameters.Add("@OperateUser", SqlDbType.NVarChar);
cmd.Parameters.Add("@OperateTime", SqlDbType.DateTime);
cmd.Parameters.Add("@OperateType", SqlDbType.NVarChar);
cmd.Parameters.Add("@WorkflowId", SqlDbType.UniqueIdentifier);
//设置参数值
cmd.Parameters["@Name"].Value = this.Name == null ? "" : this.Name;
cmd.Parameters["@PassWord"].Value = this.PassWord == null ? "" : this.PassWord;
cmd.Parameters["@Age"].Value = this.Age;
cmd.Parameters["@Option"].Value = this.Option == null ? "" : this.Option;
cmd.Parameters["@State"].Value = this.State == null ? "" : this.State;
cmd.Parameters["@BelongUser"].Value = this.BelongUser == null ? "" : this.BelongUser;
cmd.Parameters["@OperateUser"].Value = this.OperateUser == null ? "" : this.OperateUser;
cmd.Parameters["@OperateTime"].Value = this.OperateTime;
cmd.Parameters["@OperateType"].Value = this.OperateType == null ? "" : this.OperateType;
cmd.Parameters["@WorkflowId"].Value = this.WorkflowId;
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();
} public DataTable Get(int Id)
{
SqlConnection conn = new SqlConnection(ConstringSql);
string strSql = string.Format("SELECT * FROM WorkflowRegister WHERE Id = {0}", Id);
DataTable dt = new DataTable();
SqlDataAdapter da = new SqlDataAdapter(strSql, conn);
da.Fill(dt);
if (dt.Rows.Count > )
{
return dt;
}
return null;
} public DataTable GetNewestByState(string State)
{
SqlConnection conn = new SqlConnection(ConstringSql);
string strSql = string.Format("SELECT W1.* FROM WorkflowRegister AS W1 LEFT JOIN WorkflowRegister AS W2 ON W1.WorkflowId = W2.WorkflowId AND W1.OperateTime < W2.OperateTime WHERE W2.Id IS NULL AND W1.State = '{0}'", State);
DataTable dt = new DataTable();
SqlDataAdapter da = new SqlDataAdapter(strSql, conn);
da.Fill(dt);
if (dt.Rows.Count > )
{
return dt;
}
return null;
}
}
代码贴得差不多了，来看看运行效果：
版主能够看到状态为"审核回退"案件列表：
管理员能够看到状态为"等待审核"的列表：
提交页面如下：
当一条流程完整走下来，数据库信息大致如下：
WF如果运用得当，应该能够帮助自己更好地理清流程走向。对于工作流之外的开发者来说，就只管Next(),Next()就可以了。
下一篇文章应该是考虑，如果将下一步的角色、选择用户的功能等内容也封装进入流程。