就不解释抽象工厂是什么了，直接上代码：

两个具体类： public Department() {     Console.WriteLine("创建了一个Department"); } public User() {     Console.WriteLine("创建了一个User"); }
负责Department的 interface IDepartment {     void Insert(Department department);     Department GetDepartment(int id); } class AccessDepartment : IDepartment {     public AccessDepartment()     {         Console.WriteLine("调用了AccessDepartment的构造函数");     }
    #region IDepartment 成员
    public void Insert(Department department)     {         Console.WriteLine("在Access里给部门表增加记录");     }
    public Department GetDepartment(int id)     {         Console.WriteLine("在Access里根据ID得到部门表一条记录");         return null;     }
    #endregion } class SqlserverDepartment:IDepartment {     public SqlserverDepartment()     {         Console.WriteLine("调用了SqlserverDepartment的构造函数");     }
    #region IDepartment 成员
    public void Insert(Department department)     {         Console.WriteLine("在SQL里给部门表增加记录");     }
    public Department GetDepartment(int id)     {         Console.WriteLine("在SQL里根据ID得到部门表一条记录");         return null;     }
    #endregion }
负责User的 interface IUser {     void Insert(User user);     User GetUser(int id); } class AccessUser : IUser {     #region IUser 成员
    public void Insert(User user)     {         Console.WriteLine("通过AccessUser类里的IUser成员函数Insert创建了一个新的User");     }
    public User GetUser(int id)     {         Console.WriteLine("通过AccessUser类里的IUser成员函数GetUser取得ID为{0}的user编号", id);         return null;     }
    #endregion } class SqlserverUser:IUser {     #region IUser 成员
    public void Insert(User user)     {         Console.WriteLine("通过SqlserverUser类里的IUser成员函数Insert创建了一个新的User");     }
    public User GetUser(int id)     {         Console.WriteLine("通过SqlserverUser类里的IUser成员函数GetUser取得ID为{0}的user编号", id);         return null;     }
    #endregion }
工厂： //所有工厂的抽象——抽象工厂 interface IFactory {     //两个接口类型，由客户程序通过向上转换原则new出具体类的对象     IUser CreateUser();     IDepartment CreateDepartment(); } class AccessFactory : IFactory {     public AccessFactory()     {         Console.WriteLine("调用了SqlServerFactory的构造函数");     }
    #region IFactory 成员
    public IUser CreateUser()     {         Console.WriteLine("通过AccessFactory类里的IFactory成员函数CreateUser创建了一个新的AccessUser");         return new AccessUser();     }
    public IDepartment CreateDepartment()     {         Console.WriteLine("通过AccessFactory类里的IFactory成员函数IDepartment创建了一个新的AccessDepartment");         return new AccessDepartment();     }
    #endregion } class SqlServerFactory:IFactory {     public SqlServerFactory()     {         Console.WriteLine("调用了SqlServerFactory的构造函数");     }
    #region IFactory 成员
    public IUser CreateUser()     {         Console.WriteLine("通过SqlServerFactory类里的IFactory成员函数CreateUser创建了一个新的SqlserverUser");         return new SqlserverUser();     }
    public IDepartment CreateDepartment()     {         Console.WriteLine("通过SqlServerFactory类里的IFactory成员函数CreateDepartment创建了一个新的SqlserverDepartment");         return new SqlserverDepartment();     }
    #endregion }
客户端： static void Main(string[] args) {     //创建两个数据表对象     Console.WriteLine("\n调用User user = new User();");     User user = new User();     Console.WriteLine("\n调用Department dept = new Department();");     Department dept = new Department();
    //变化点：创建一个抽象工厂，new具体的工厂     Console.WriteLine("\n调用IFactory ifactory = new SqlServerFactory();");     IFactory ifactory = new SqlServerFactory();     //Console.WriteLine("\n调用IFactory ifactory = new AccessFactory();");     //IFactory ifactory = new AccessFactory();
    //通过接口创建user执行具体操作     Console.WriteLine("\n调用IUser iuser = ifactory.CreateUser();");     IUser iuser = ifactory.CreateUser();     Console.WriteLine("\n调用iuser.Insert(user);");     iuser.Insert(user);     Console.WriteLine("\n调用iuser.GetUser(1);");     iuser.GetUser(1);
    //通过接口创建department执行具体操作     Console.WriteLine("\n调用IDepartment idepartment = ifactory.CreateDepartment();");     IDepartment idepartment = ifactory.CreateDepartment();     Console.WriteLine("\n调用idepartment.Insert(dept);");     idepartment.Insert(dept);     Console.WriteLine("\n调用idepartment.GetDepartment(1);");     idepartment.GetDepartment(1);
    Console.ReadKey(); }