注释很全的抽象工厂（没用简单工厂优化）

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();
}