Observer pettern

using System;
using System.Collections;

namespace Factory
{
 /// <summary>
 /// 普通的正常做法
 /// </summary>
 /*
 public class ATM
 {
  BankAccount bankAccount;
  void process(int data)
  {
   bankAccount.Withdraw(data);
  }
 }
 public class BankAccount
 {
  Emailer emailer;//紧耦合
  Mobile mobile;//紧耦合

  public void Withdraw(int d)
  {
   //...
   emailer.SendEmail("email");
   mobile.Send("phone");
  }
 }
 public class Emailer
 {
  public void SendEmail(string to)
  {
   //...
  }
 }
 public class Mobile
 {
  public void Send(string phone)
  {
  }
 }
 */
 //--------------------------------------------------
//observer pettern设计模式
//--------------------------------------------------
 public class UserAccountArgs
 {
  public string moble;
  public string email;
  public UserAccountArgs()
  {
  }
 }
---------------------------------------------
--IB
---------------------------------------------
 public interface IAccountObserver
 {
  void Update(UserAccountArgs args);
 }
-------------
--B1
------------
 public class Emailer:IAccountObserver
 {
  public void SendEmail(string to)
  {
   //...
  }

  public void Update(UserAccountArgs args)
  {
   string email=args.email;
   SendEmail(email);
  }
 }
--------------
--B2
--------------
 public class Mobile:IAccountObserver
 {
  public void Send(string phone)
  {
  }
  public void Update(UserAccountArgs args)
  {
   string mobile=args.moble;
   Send(mobile);
  }
 }

--------------------------------------------------------------------
--A1
---------------------------------------------------------------------
 public class BankAccount:Subject
 {
  UserAccountArgs userAccount;
  
  
  public void Withdraw(int d)
  {
   userAccount=new UserAccountArgs();

   Notify(userAccount);
  }
 }

--------------------------------------------------
-把稳定的操作抽出来 IA
--------------------------------------------------
 public abstract class Subject
 {
  ArrayList IAccountList=new ArrayList();
  public void Add(IAccountObserver Ia)
  {
   IAccountList.Add(Ia);
  }
  public void Remove(IAccountObserver Ia)
  {
   IAccountList.Remove(Ia);
  }
  public virtual void Notify(UserAccountArgs userAccount)
  {
   foreach(IAccountObserver Ia in IAccountList)
   {
    Ia.Update(userAccount);
   }
  }

 }
}