//定義事件和對(duì)應(yīng)的委托
public event MyDelegate Click;
public delegate void MyDelegate();

//定義委托
void OnClick(){
  console.writeline("you just clicked me!");
}

//將委托與事件關(guān)聯(lián)
Click += OnClick;

//觸發(fā)事件
Click();

/*事件類*/
public Event {
  //與事件相關(guān)的事件處理函數(shù)
  public ArrayList<Callback> callbackList;
  
  //事件觸發(fā)函數(shù)
  public void emit(){
    for(Callback cb : callbackList){
      cb.run();
    }
  }
  
  //注冊(cè)事件處理函數(shù)
  public registerCallback(Callback cb){
    callbackList.add(cb);
  }
}

/*事件處理函數(shù)類*/
public interface Callback {
  void run();
}

public OnClick implements Callback {
  //函數(shù)
  public void run(){
    System.out.println("you just clicked me!");
  }
  
  
/*實(shí)現(xiàn)事件驅(qū)動(dòng)*/
Event e = new Event(); 
//將OnClick事件處理函數(shù)注冊(cè)到事件中
e.registerCallback(new OnClick()); 
//觸發(fā)事件
e.emit();

/*事件處理類*/
public class EventHandler {
  //事件源
  private Object sender;
  //事件處理函數(shù)名稱（用于反射）
  private String callback;
  
  public EventHandler(Object sender, String callback){
    this.sender = sender;
    this.callback = callback;
  }
  
  //事件觸發(fā)
  public void emit(){
  Class senderType = this.sender.getClass();
  try {
    //獲取并調(diào)用事件源sender的事件處理函數(shù)
    Method method = senderType.getMethod(this.callback);
    method.invoke(this.sender);
    } catch (Exception e2) {
      e2.printStackTrace();
    }
  }
}


/*事件源*/
public class Button(){
  /*可以在此設(shè)置Button類的相關(guān)屬性，比如名字等*/
  private String name;
  ...
  
  
  //事件處理函數(shù)
  public void onClick(){
    System.out.println("you just clicked me!");
  }
}
  
  
/*實(shí)現(xiàn)事件驅(qū)動(dòng)機(jī)制*/
Button b = new Button();
if(/*收到按鈕點(diǎn)擊信號(hào)*/){
  EventHandler e = new EventHandler(b, "onClick");
  e.emit();
}

public class EventArgs {
  //參數(shù)
  String p1;
  Integer p2;
  ...
  
}

//onClick事件處理函數(shù)改寫
public void onClick(Object sender, EventArgs e){
  //參數(shù)e提供更多的信息
  System.out.println("Hello, you clicked me! " + e.p1 + e.p2);
}

//觸發(fā)函數(shù)emit改寫
public void emit(EventArgs e){
Class senderType = this.sender.getClass();
try {
  //獲取并調(diào)用事件源sender的事件處理函數(shù)
  Method method = senderType.getMethod(this.callback, this.getClass(), e.getClass());
  method.invoke(this.sender, this.sender, e);
  } catch (Exception e2) {
    e2.printStackTrace();
  }
}