C#_delegate和事件 - 如果金额小于0则触发事件

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading;//如果账户金额小于0 触发事件namespace Starter{    public delegate int DeleageteClass(out DateTime start, out DateTime stop);    class Program    {        static void Main(string[] args)        {            Bank account = new Bank();            account.NSF += NSFHandler;  //绑定账户小于0时候的事件            account.Deposit(500);            account.WithDrawal(750);            Console.ReadLine();        }        public static void NSFHandler(object o, BankEventArgs e)   //如果小于0时候的会发生的事件        {            Console.WriteLine("NSF Transaction");            Console.WriteLine("Balance: "+e.Balance);            Console.WriteLine("Transaction: "+ e.Transaction);        }    }    public delegate void OverDrawn(object o,BankEventArgs e);    public class Bank {        public event OverDrawn NSF;  //定义委托事件的属性        public decimal Deposit(decimal amountDeposit)        {            propBalance += amountDeposit;            return propBalance;        }        public decimal WithDrawal(decimal amountWithdrawn)        {            decimal newBalance = propBalance - amountWithdrawn;            if (newBalance < 0)            {                if (NSF != null)                         {                    //BankEventArgs 用于记录当前类相关信息，供事件调用                    BankEventArgs args = new BankEventArgs(Balance,amountWithdrawn);                    //事件调用 - 方法NSFHandler                    NSF(this, args);                }            }            return propBalance = newBalance;                    }        private decimal propBalance=0;        public decimal Balance        {            get            {                return propBalance;            }        }    }    public class BankEventArgs : EventArgs    {        public BankEventArgs(decimal amountBalance,decimal amountTransaction)        {            propTransaction = amountTransaction;            propBalance = amountBalance;        }        private decimal propBalance;        public decimal Balance        {            get {                return propBalance;            }        }        private decimal propTransaction;        public decimal Transaction        {            get            {                return propTransaction;            }        }    }}