委托和事件(标识)

using System;
namespace Events
{
delegate void SomeDelegate(string sender);
interface ISomeInterface
{
event SomeDelegate SomeEvent;
void PerformSomeEvent();
void SomeEventHandler(string sender);
}
abstract class AbstractClass:ISomeInterface
{
public virtual event SomeDelegate SomeEvent;
public abstract void SomeEventHandler(string sender);
public abstract void PerformSomeEvent();
protected void PerformSomeEventInternal(string sender)//9 (根据8,sender为
Some Class)
{
if(null!=SomeEvent)
{
SomeEvent(sender);//10 (也就是执行//3、//4、//5的方法)
}
}
protected void SomeEventHandlerInternal(string sender,string receiver)//13 (根据12,receiver为Some Class)//16(根据15,receiver为Another Class)
{
Console.WriteLine("some event has been handler");
Console.WriteLine(" Sender is ["+ sender+"]");
Console.WriteLine("Receiver is ["+receiver+"]");
Console.WriteLine("------------------------------------");
}
}
class SomeClass:AbstractClass,ISomeInterface
{
public override void PerformSomeEvent()//7
{
PerformSomeEventInternal("Some Class"); //8
}
public override void SomeEventHandler(string sender)//11
{
SomeEventHandlerInternal(sender,"Some Class");//12
}
}
class AnotherClass:AbstractClass,ISomeInterface
{
public override void PerformSomeEvent()
{
PerformSomeEventInternal("Another Class");
}
public override void SomeEventHandler(string sender)//14
{
SomeEventHandlerInternal(sender,"Another Class");//15
}
}
class SomeApplication
{
public static void SomeEventStaticHander(string sender)//17
{
Console.WriteLine("some event has been handler.");
Console.WriteLine(" Sender is ["+ sender+"]");
Console.WriteLine("Receiver is [some application]");
Console.WriteLine("-------------------------------------");
}
static void Main(string [] args)//程序运行起始点
{
SomeClass someclass=new SomeClass(); //1
AnotherClass anotherclass=new AnotherClass();//2
someclass.SomeEvent+=new SomeDelegate(someclass.SomeEventHan dler); //3
someclass.SomeEvent+=new SomeDelegate(anotherclass.SomeEventHa ndler);//4
someclass.SomeEvent+=new SomeDelegate(SomeApplication.SomeEve ntStaticHander);//5
someclass.PerformSomeEvent();//6
Console.ReadLine(); //18
}
}
}
备注：程序步骤：
1. 分别实例化相应的两个类SomeClass、AnotherClass
2.类中的方法1、2、3和委托SomeDelegate返回值、参数一致（编译器）
3.将委托对应的三个方法添加到事件（委托链）中
4.执行事件（相应的方法）。

具体过程见程序“//”标识，数字为流程。