using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication1{ public class User {  private string username;  public string Username  {   get { return username; }   set { username = value; }  }  private string sex;  public string Sex  {   get { return sex; }   set { sex = value; }  }  private string age;  public string Age  {   get { return age; }   set { age = value; }  }  private string phone;  public string Phone  {   get { return phone; }   set { phone = value; }  } }}

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Collections;namespace ConsoleApplication1{ public class Controller {  private ArrayList a = new ArrayList();  public ArrayList A  {   get { return a; }   set { a = value; }  }  public void add(User user)   {   A.Add(user);  }  public void delete(User user)   {   if (A.Contains(user))   {    A.Remove(user);   }   else   {    Console.WriteLine("用戶不存在！");   }  }  public ArrayList select(ArrayList a)   {   return a;  }  public User search(string username)  {   foreach(User user in A)   {    if (user.Username == username)    {     return user;    }   }   return null;  } }}

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Collections;namespace ConsoleApplication1{ class Program {  static void Main(string[] args)  {   Controller controller = new Controller();   while (true)   {    Console.WriteLine("請輸入您的操作：");    Console.WriteLine("1,增加用戶");    Console.WriteLine("2,刪除用戶");    Console.WriteLine("3,瀏覽用戶");    Console.WriteLine("4,退出");    string input = Console.ReadLine();    if(input=="1")    {     User user = new User();     Console.WriteLine("用戶姓名：");     user.Username = Console.ReadLine();     Console.WriteLine("用戶姓別：");     user.Sex = Console.ReadLine();     Console.WriteLine("用戶年齡：");     user.Age = Console.ReadLine();     Console.WriteLine("電話號碼：");     user.Phone = Console.ReadLine();     controller.add(user);    }    if(input=="2")    {     Console.WriteLine("請輸入用戶姓名");     string username = Console.ReadLine();     if (controller.search(username)!=null)     {      User user = controller.search(username);      controller.delete(user);     }     else     {      Console.WriteLine("該用戶不存在！");     }    }    if(input=="3")    {     foreach(User user in controller.A )     {      Console.WriteLine(user.Username);     }    }   }  } }}