public Subscriber(string id, Sender sender)
{
this.id = id;
//步骤6．用+=操作符添加事件到事件队列中（-=操作符能够将事件从队列中删除）。
sender.DebugEvent += new DemoEventHandler(MyEvent);
}
static void Main(string[] args)
{
Sender sender = new Sender();
Subscriber subscriber1 = new Subscriber("1",sender);
Subscriber subscriber2 = new Subscriber("2",sender);
sender.Debug("demo");
Console.ReadKey();
}