说明

　　WF作为一种以交互式开发与流程控制为基础的SDK,实例内部与外部的通信是由WorkflowQueuingService完成的，WorkflowQueuingService维护了一个Queue,实例向WorkflowQueuingService添加Queue（CreateWorkflowQueue方法）,并定阅　　QueueItemAvailable事件，外部通过EnqueueItem方法将消息发送到指定工作流队列。

　　WorkflowQueuingService的使用我在前面的例子中已多次使用。

　　本例是一个提前提交队列消息的实现:

　　[A挂起] -> [B挂起] -> [C挂起]

　　当流程运行到[A挂起],提交[A挂起]，将进入[B挂起]，提交[B挂起]，将进入[C挂起]

　　本例可以在运行到[A挂起]时，先提交[B挂起]，遭提交[A挂起]，这样流程运行完[A挂起]后，在[B挂起]不会等待，将直接运行完[B挂起]，将进入[C挂起]

　　例子: http://files.cnblogs.com/wxwinter/aec12.rar

　　例子

　　[5012提前提交]

　　通信接口

public interface 通信接口
{
string Text { set; get; }
IComparable QueueName { set; get; }
}
public class 通信类 : WorkflowRuntimeService, 通信接口
{
public string Text
{ set; get; }
　　
public IComparable QueueName
{ set; get; }
　　
public void NextStep(Guid instanceID, object inputData)
{
WorkflowInstance instance = Runtime.GetWorkflow(instanceID);
instance.EnqueueItemOnIdle(QueueName, inputData, null, null);
}
public void NextStep(Guid instanceID, object inputData,string qn)
{
WorkflowInstance instance = Runtime.GetWorkflow(instanceID);
instance.EnqueueItemOnIdle(qn, inputData, null, null);
}
}

　　等待触发Activity

public class 等待触发 : Activity, IActivityEventListener<QueueEventArgs>, IEventActivity
{
　　
public string Text
{ set; get; }
　　
protected override void Initialize(IServiceProvider provider)
{
System.Console.WriteLine(this.Name + ":进入队列(Initialize)");
　　
WorkflowQueuingService queueService = provider.GetService(typeof(WorkflowQueuingService)) as WorkflowQueuingService;
　　
WorkflowQueue queue = queueService.CreateWorkflowQueue(this.QueueName, false);
　　
通信接口 obj =provider.GetService(typeof(通信接口)) as 通信接口;
　　
obj.QueueName = this.QueueName;
　　
obj.Text = this.Text;
　　
base.Initialize(provider);
}
　　
protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
{
if (myProcessAEC(executionContext))
{
return ActivityExecutionStatus.Closed;
}
else
{
Subscribe(executionContext, this);
return ActivityExecutionStatus.Executing;
}
}
　　
private bool myProcessAEC(ActivityExecutionContext provider)
{
WorkflowQueuingService queueService = provider.GetService<WorkflowQueuingService>();
if (queueService.Exists(this.QueueName) && queueService.GetWorkflowQueue(this.QueueName).Count > 0)
{
object inputData = queueService.GetWorkflowQueue(this.QueueName).Dequeue();
　　
System.Console.WriteLine(this.Name + ":外部传入的数据:" + inputData.ToString());
　　
通信接口 obj = provider.GetService<通信接口>();
　　
this.Text = obj.Text;
return true;
}
return false;
}
　　
//实现IActivityEventListener<QueueEventArgs> 的[发生订阅事件时的处理过程]事件方法
　　
public void OnEvent(object sender, QueueEventArgs e)
{
ActivityExecutionContext aec = sender as ActivityExecutionContext;
if (myProcessAEC(aec))
{
Unsubscribe(aec, this);
aec.CloseActivity();
}
}
　　
//实现IEventActivity的[WorkflowQueue名称]属性
public IComparable QueueName
{
get { return this.QualifiedName; }
}
　　
//实现IEventActivity的[事件的订阅]方法
public void Subscribe(ActivityExecutionContext parentContext, IActivityEventListener<QueueEventArgs> parentEventHandler)
{
WorkflowQueuingService queueService = parentContext.GetService(typeof(WorkflowQueuingService)) as WorkflowQueuingService;
　　
WorkflowQueue queue = queueService.GetWorkflowQueue(this.QueueName);
　　
queue.RegisterForQueueItemAvailable(parentEventHandler);
　　
通信接口 obj = parentContext.GetService<通信接口>();
if (obj != null)
{
obj.QueueName = this.QueueName;
obj.Text = this.Text;
}
　　
}
//实现IEventActivity的[取消事件的订阅]方法
public void Unsubscribe(ActivityExecutionContext parentContext, IActivityEventListener<QueueEventArgs> parentEventHandler)
{
WorkflowQueuingService queueService = parentContext.GetService<WorkflowQueuingService>();
if (queueService != null && queueService.Exists(this.QueueName))
{
queueService.GetWorkflowQueue(this.QueueName).UnregisterForQueueItemAvailable(parentEventHandler);
queueService.DeleteWorkflowQueue(this.QueueName);
}
}
}

　　测试用工作流

public class Workflow1: SequentialWorkflowActivity
　　{
　　　　public Workflow1()
　　　　{
　　　　　　InitializeComponent();
　　　　}
　　
[System.Diagnostics.DebuggerNonUserCode]
private void InitializeComponent()
{
this.CanModifyActivities = true;
this.b = new wxwinterAecTest.等待触发();
this.codeActivity1 = new System.Workflow.Activities.CodeActivity();
this.a = new wxwinterAecTest.等待触发();
//
// b
//
this.b.Name = "b";
this.b.Text = null;
//
// codeActivity1
//
this.codeActivity1.Name = "codeActivity1";
this.codeActivity1.ExecuteCode += new System.EventHandler(this.codeActivity1_ExecuteCode);
//
// a
//
this.a.Name = "a";
this.a.Text = null;
//
// Workflow1
//
this.Activities.Add(this.a);
this.Activities.Add(this.codeActivity1);
this.Activities.Add(this.b);
this.Name = "Workflow1";
this.CanModifyActivities = false;
　　
}
　　
private 等待触发 b;
private CodeActivity codeActivity1;
private 等待触发 a;
private void codeActivity1_ExecuteCode(object sender, EventArgs e)
{
System.Console.WriteLine("codeActivity1");
}
　　}

　　宿主

WorkflowRuntime workflowRuntime = new WorkflowRuntime();
通信类 obj = new 通信类();
WorkflowInstance instance;
　　
private void Form1_Load(object sender, EventArgs e)
{
workflowRuntime.AddService(obj);
　　
workflowRuntime.WorkflowCompleted += new EventHandler<WorkflowCompletedEventArgs>(workflowRuntime_WorkflowCompleted);
workflowRuntime.WorkflowTerminated += new EventHandler<WorkflowTerminatedEventArgs>(workflowRuntime_WorkflowTerminated);
workflowRuntime.WorkflowIdled += new EventHandler<WorkflowEventArgs>(workflowRuntime_WorkflowIdled);
　　
}
//启动流程
private void button1_Click(object sender, EventArgs e)
{
instance = workflowRuntime.CreateWorkflow(typeof(Workflow1));
instance.Start();
　　
}
　　
//操作
private void button2_Click(object sender, EventArgs e)
{
　　
obj.NextStep(instance.InstanceId, this.textBox1.Text, textBox2.Text);
}
　　
static void workflowRuntime_WorkflowIdled(object sender, WorkflowEventArgs e)
{
System.Console.WriteLine("--------------------WorkflowIdled------------------");
　　
}
　　
static void workflowRuntime_WorkflowTerminated(object sender, WorkflowTerminatedEventArgs e)
{
System.Console.WriteLine("Terminated" + e.Exception.Message);
}
　　
static void workflowRuntime_WorkflowCompleted(object sender, WorkflowCompletedEventArgs e)
{
System.Console.WriteLine("===================WorkflowCompleted=================");
}

　　运行结果

　　正常顺序

　　提前提交

　　等待触发Activity

public class 等待触发 : Activity, IActivityEventListener<QueueEventArgs>, IEventActivity
{
　　
public string Text
{ set; get; }
　　
protected override void Initialize(IServiceProvider provider)
{
System.Console.WriteLine(this.Name + ":进入队列(Initialize)");
　　
WorkflowQueuingService queueService = provider.GetService(typeof(WorkflowQueuingService)) as WorkflowQueuingService;
　　
WorkflowQueue queue = queueService.CreateWorkflowQueue(this.QueueName, false);
　　
通信接口 obj =provider.GetService(typeof(通信接口)) as 通信接口;
　　
obj.QueueName = this.QueueName;
　　
obj.Text = this.Text;
　　
base.Initialize(provider);
}
　　
protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
{
if (myProcessAEC(executionContext))
{
return ActivityExecutionStatus.Closed;
}
else
{
Subscribe(executionContext, this);
return ActivityExecutionStatus.Executing;
}
}
　　
private bool myProcessAEC(ActivityExecutionContext provider)
{
WorkflowQueuingService queueService = provider.GetService<WorkflowQueuingService>();
if (queueService.Exists(this.QueueName) && queueService.GetWorkflowQueue(this.QueueName).Count > 0)
{
object inputData = queueService.GetWorkflowQueue(this.QueueName).Dequeue();
　　
System.Console.WriteLine(this.Name + ":外部传入的数据:" + inputData.ToString());
　　
通信接口 obj = provider.GetService<通信接口>();
　　
this.Text = obj.Text;
return true;
}
return false;
}
　　
//实现IActivityEventListener<QueueEventArgs> 的[发生订阅事件时的处理过程]事件方法
　　
public void OnEvent(object sender, QueueEventArgs e)
{
ActivityExecutionContext aec = sender as ActivityExecutionContext;
if (myProcessAEC(aec))
{
Unsubscribe(aec, this);
aec.CloseActivity();
}
}
　　
//实现IEventActivity的[WorkflowQueue名称]属性
public IComparable QueueName
{
get { return this.QualifiedName; }
}
　　
//实现IEventActivity的[事件的订阅]方法
public void Subscribe(ActivityExecutionContext parentContext, IActivityEventListener<QueueEventArgs> parentEventHandler)
{
WorkflowQueuingService queueService = parentContext.GetService(typeof(WorkflowQueuingService)) as WorkflowQueuingService;
　　
WorkflowQueue queue = queueService.GetWorkflowQueue(this.QueueName);
　　
queue.RegisterForQueueItemAvailable(parentEventHandler);
　　
通信接口 obj = parentContext.GetService<通信接口>();
if (obj != null)
{
obj.QueueName = this.QueueName;
obj.Text = this.Text;
}
　　
}
//实现IEventActivity的[取消事件的订阅]方法
public void Unsubscribe(ActivityExecutionContext parentContext, IActivityEventListener<QueueEventArgs> parentEventHandler)
{
WorkflowQueuingService queueService = parentContext.GetService<WorkflowQueuingService>();
if (queueService != null && queueService.Exists(this.QueueName))
{
queueService.GetWorkflowQueue(this.QueueName).UnregisterForQueueItemAvailable(parentEventHandler);
queueService.DeleteWorkflowQueue(this.QueueName);
}
}
}