本系列以ActivityExecutionContext 对像为主线，通过以自定义Activity为例子演示了控制Activity内部执行的一些技巧。如果真正的读懂了本文，就能更好的理解WF工具栏中自带Activity的，并重新实现其功能。

　　实际上，如果开发业务工作流，直接用WF工具栏中自带Activity拼装会使流程显得很臃肿，而状态机与顺序工作流其实也不过是WF为我们提供的两个简单的Activity执行控制模板而以，WF只的两个Activity,(System.Workflow.ComponentModel.Activity与System.Workflow.ComponentModel.CompositeActivity)，它们是活动树上的叶节点与支节点，当你直正理解了这些你会发现让人眼花缭乱的WF背后是如此清爽幽雅，WF仿佛在一个全新的空间再现了计算机工作原理，指令、地址、数据、出栈、入栈.........

　　最后以一个简单的例子结束本系例:

　　实现Visio设计风格的Activity

　　先看一下我的一个项目中的效果

　　下面是一个按连接线顺序调用的例子

　　http://files.cnblogs.com/wxwinter/AEC13.rar

　　结点Activity

public class 结点: Activity
　　{
public Activity 上一结点
{ set; get; }
public Activity 下一结点
{ set; get; }
　　
protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
{
System.Console.WriteLine(this.Name);
return ActivityExecutionStatus.Closed;
}
　　}

　　容器Designer

public class wxwinterDesigner : FreeformActivityDesigner
{
public wxwinterDesigner()
{
this.ConnectorAdded += new ConnectorEventHandler(wxwinterDesigner_ConnectorAdded);
this.ConnectorChanged += new ConnectorEventHandler(wxwinterDesigner_ConnectorChanged);
this.ConnectorRemoved += new ConnectorEventHandler(wxwinterDesigner_ConnectorRemoved);
}
　　
void wxwinterDesigner_ConnectorChanged(object sender, ConnectorEventArgs e)
{
结点 s = e.Connector.Source.AssociatedDesigner.Activity as 结点;
结点 t = e.Connector.Target.AssociatedDesigner.Activity as 结点;
　　
s.下一结点 = t;
t.上一结点 = s;
　　
}
　　
void wxwinterDesigner_ConnectorRemoved(object sender, ConnectorEventArgs e)
{
结点 s = e.Connector.Source.AssociatedDesigner.Activity as 结点;
结点 t = e.Connector.Target.AssociatedDesigner.Activity as 结点;
　　
t.上一结点 =null ;
s.下一结点 =null;
}
　　
void wxwinterDesigner_ConnectorAdded(object sender, ConnectorEventArgs e)
{
结点 s = e.Connector.Source.AssociatedDesigner.Activity as 结点;
结点 t = e.Connector.Target.AssociatedDesigner.Activity as 结点;
s.下一结点 = t;
t.上一结点 = s;
}
}

　　容器Activity

[Designer(typeof(wxwinterDesigner), typeof(IDesigner))]
　　public class 容器: SequenceActivity
　　{
public 结点 开始结点
{ set; get; }
　　
protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
{
if (开始结点 != null)
{
开始结点.Closed += node_Closed;
executionContext.ExecuteActivity(开始结点);
return ActivityExecutionStatus.Executing;
}
else
{
return ActivityExecutionStatus.Closed;
}
}
　　
void node_Closed(object sender, ActivityExecutionStatusChangedEventArgs e)
{
ActivityExecutionContext executionContext = sender as ActivityExecutionContext;
结点 node = e.Activity as 结点;
node.Closed -= node_Closed;
　　
if (node.下一结点 == null || node.下一结点.ExecutionStatus == ActivityExecutionStatus.Closed)
{
executionContext.CloseActivity();
}
else
{
　　
node.下一结点.Closed += node_Closed;
executionContext.ExecuteActivity(node.下一结点);
}
　　
}
　　}

　　宿主

class Program
{
static void Main()
{
WorkflowRuntime workflowRuntime = new WorkflowRuntime();
workflowRuntime.WorkflowCompleted +=new EventHandler<WorkflowCompletedEventArgs>(workflowRuntime_WorkflowCompleted);
workflowRuntime.WorkflowTerminated +=new EventHandler<WorkflowTerminatedEventArgs>(workflowRuntime_WorkflowTerminated);
workflowRuntime.WorkflowIdled+=new EventHandler<WorkflowEventArgs>(workflowRuntime_WorkflowIdled);
WorkflowInstance instance = workflowRuntime.CreateWorkflow(typeof(Workflow1));
instance.Start();
　　
System.Console.Read();
　　
}
　　
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");
}
　　
}

　　使用

　　运行效果

　　容器Designer

public class wxwinterDesigner : FreeformActivityDesigner
{
public wxwinterDesigner()
{
this.ConnectorAdded += new ConnectorEventHandler(wxwinterDesigner_ConnectorAdded);
this.ConnectorChanged += new ConnectorEventHandler(wxwinterDesigner_ConnectorChanged);
this.ConnectorRemoved += new ConnectorEventHandler(wxwinterDesigner_ConnectorRemoved);
}
　　
void wxwinterDesigner_ConnectorChanged(object sender, ConnectorEventArgs e)
{
结点 s = e.Connector.Source.AssociatedDesigner.Activity as 结点;
结点 t = e.Connector.Target.AssociatedDesigner.Activity as 结点;
　　
s.下一结点 = t;
t.上一结点 = s;
　　
}
　　
void wxwinterDesigner_ConnectorRemoved(object sender, ConnectorEventArgs e)
{
结点 s = e.Connector.Source.AssociatedDesigner.Activity as 结点;
结点 t = e.Connector.Target.AssociatedDesigner.Activity as 结点;
　　
t.上一结点 =null ;
s.下一结点 =null;
}
　　
void wxwinterDesigner_ConnectorAdded(object sender, ConnectorEventArgs e)
{
结点 s = e.Connector.Source.AssociatedDesigner.Activity as 结点;
结点 t = e.Connector.Target.AssociatedDesigner.Activity as 结点;
s.下一结点 = t;
t.上一结点 = s;
}
}

　　容器Activity