DependencyProperty事件

 1.     DependencyProperty事件本质上与DependencyProperty从属属性一样，细节操作见DependencyProperty从属属性

2.     DependencyProperty事件只能绑定到事件，而不能绑定到委托

   DependencyProperty事件只能赋值到委托

3.     即使用+=方式为事件添加订阅，原有的绑定也会被移除

说明:

[事件A] 绑定到 [事件B]

[事件A] + = [委托1];

[事件B] + = [委托2];

触发[[事件A],将执行 [委托1],不会执行[委托2],绑定已被清除

4.     多个绑定都会被执行

A节点.A事件 += [委托1]

B节点.B事件 绑定到 [A.A事件]

C节点.C事件 绑定到 [A.A事件]

执行A、B、C节点,[委托1]会被执行3次

1.1      AddHandler、RemoveHandler 通过从属属性添加、移除事件定阅

System.Workflow.ComponentModel.DependencyObject的实例方法

public void AddHandler(DependencyProperty dependencyEvent, object value);

实例.AddHandler(类.DependencyProperty事件,委托)

public void RemoveHandler(DependencyProperty dependencyEvent, object value);

实例.RemoveHandler(类.DependencyProperty事件,委托)

this.AddHandler(EAEvent, new System.EventHandler(OnEA));

1.2      定义一个有DependencyProperty事件的Activity

     public class Activity1:Activity

     {

        //为事件绑定操作

        protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)

        {

            //第一种绑定方式

            this.AddHandler(Activity1.EAEvent, new System.EventHandler(OnEA));

            //第二种绑定方式

            //this.EA += new System.EventHandler(OnEA);

           

            return base.Execute(executionContext);

        }

        //事件要执行的操作

        void OnEA(object sender, EventArgs e)

        {

            System.Console.WriteLine("EA");

        }

        //定义DependencyProperty事件

        public static DependencyProperty EAEvent = DependencyProperty.Register("EA", typeof(EventHandler), typeof(Activity1));

        //定义事件

        public event EventHandler EA

        {

            add

            {

               base.AddHandler(Activity1.EAEvent, value);

            }

            remove

            {

                base.RemoveHandler(Activity1.EAEvent, value);

            }

        }

     }

事件的绑定也可在类外部进行

private Activity1 activity11;

this.activity11 = new Activity1();

this.activity11.EA += new EventHandler(activity11_EA);

this.activity11.AddHandler(Activity1.EAEvent, new System.EventHandler(activity11_EA));

1.3      SetBinding代码方式的绑定

详细见DependencyProperty从属属性

System.Workflow.ComponentModel.ActivityBind activitybind1 = new System.Workflow.ComponentModel.ActivityBind();

activitybind1.Name = "codeActivity3";

activitybind1.Path = "ExecuteCode";

this.activity11.SetBinding(WorkflowConsoleApplication2.Activity1.EAEvent, activitybind1);

1.4      VS设计器进行绑定

略

1.5      XOML配置文件的从属属性绑定

详细见DependencyProperty从属属性

     <CodeActivityx:Name="codeActivity1"ExecuteCode="{ActivityBind activity11,Path=EA}" />

     <CodeActivityx:Name="codeActivity2"ExecuteCode="codeActivity2_ExecuteCode" />