設計模式-抽象工廠模式

時間 2019-11-18

標籤設計模式抽象工廠简体版

原文原文鏈接

緊接着工廠方法模式的案例[http://www.cnblogs.com/adzhouyang/p/7398000.html]
當須要新增一個產品，好比新增一個Department對象時，工廠方法模式就須要修改
結構以下
html

此時，須要新增一個Department接口，以及分別用兩種數據庫訪問方式實現的具體Department對象，在抽象工廠類和具體工廠類裏，也須要新增相關的產生Department對象方法。數據庫

interface IDepartment
    {
        void Insert(Department department);

        Department GetDepartment(int id);
    }

public class AccessDepartment : IDepartment
    {
        public void Insert(Department department)
        {
            Console.WriteLine("InsertAccessDepartment");
        }

        public Department GetDepartment(int id)
        {
            Console.WriteLine("AccessDepartmentlist");
            return null;
        }
    }

public class SqlDepartment : IDepartment
    {
        public void Insert(Department department)
        {
            Console.WriteLine("InsertSqlDepartment");
        }

        public Department GetDepartment(int id)
        {
            Console.WriteLine("SqlDepartmentlist");
            return null;
        }

    }

interface IFactory
    {
        IUser CreateUser();
        //新增方法
        IDepartment CreateDepartment();
    }

public class SqlFactory : IFactory
    {
        public IUser CreateUser()
        {
            return new SqlUser();
        }

        public IDepartment CreateDepartment()
        {
            return new SqlDepartment();
        }
    }

public class AccessFactory : IFactory
    {
        public IUser CreateUser()
        {
            return new AccessUser();
        }

        public IDepartment CreateDepartment()
        {
            return new AccessDepartment();
        }
    }

public static void Main(string[] args)
        {
            User user = new User();
            Department dep = new Department();

            IFactory factory = new AccessFactory();

            IUser iu = factory.CreateUser();

            iu.Insert(user);
            iu.GetUser(1);

            IDepartment ip = factory.CreateDepartment();

            ip.Insert(dep);
            ip.GetDepartment(1);
        }

只有一個產品系列的時候，好比案例中只有一個User對象的時候，只須要用到工廠方法模式
當解決涉及到多個產品系列的問題，好比案例中增長了Department對象時，就須要用到抽象工廠模式
也就是抽象工廠模式是對工廠方法模式的擴展設計模式