通过AEC解读WF的核心原理(十三完)实现Visio设计风格的Activity
AEC,是ActivityExecutionContext 对像,也是 Activity Execution Context
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
https://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
本系列文章表
通过AEC解读WF的核心原理(二)通过AEC调用添加到引擎中的服务对像
通过AEC解读WF的核心原理(三)Execute方法Activity的入口
通过AEC解读WF的核心原理(四)AEC在内部执行childActivity
通过AEC解读WF的核心原理(五)实现一个从下向上执行的顺序容器
通过AEC解读WF的核心原理(六)创建复本ForEach循环
通过AEC解读WF的核心原理(七)一个实现Goto功能的Activity
通过AEC解读WF的核心原理(八)实现Switch功能的Activity
通过AEC解读WF的核心原理(七)一个实现Goto功能的Activity
通过AEC解读WF的核心原理(九)实现IEventActivity
通过AEC解读WF的核心原理(十一)(题外篇) WF与Windows操作系统的对比
通过AEC解读WF的核心原理(十二)WorkflowQueue的提前提交
本系列完成
wxwinter 2008-6-18