概述
抽象工厂模式为创建一组对象提供了一种解决方案。与工厂方法模式相比，抽象工厂模式中的具体工厂不只是创建一种产品，它负责创建一组产品。抽象工厂模式定义如下：
抽象工厂模式(Abstract Factory Pattern)：提供一个创建一系列相关或相互依赖对象的接口，而无须指定它们具体的类。抽象工厂模式又称为Kit模式，它是一种对象创建型模式。.
描述需求
分别往SQLserver、mysql、sqliter数据库中添加用户和部门数据。
抽象工厂实现代码
/// <summary> /// 顶层抽象工厂 /// </summary> public interface IFacatory { IDatabaseUser GetDatabaseUser(); IDatabaseDepartment GetDatabaseDepartment(); } /// <summary> /// 具体工厂 /// </summary> public class SqlliteFacatory : IFacatory { public IDatabaseDepartment GetDatabaseDepartment() { return new SqlliteDepartment(); } public IDatabaseUser GetDatabaseUser() { return new SqliteUser(); } } /// <summary> /// 具体工厂 /// </summary> public class MysqlFacatory : IFacatory { public IDatabaseDepartment GetDatabaseDepartment() { return new MysqlDepartment(); } public IDatabaseUser GetDatabaseUser() { return new MysqlUser(); } } /// <summary> /// 具体工厂 /// </summary> public class SqlserverFacatory : IFacatory { public IDatabaseDepartment GetDatabaseDepartment() { return new SqlServerDepartment(); } public IDatabaseUser GetDatabaseUser() { return new SqlServerUser(); } }
/// <summary> /// 用户类 /// </summary> public class User { public string Name { get; set; } public int Id { get; set; } } /// <summary> /// 抽象的产品 /// </summary> public interface IDatabaseUser { void InsertUser(User user); User GetUser(int id); } /// <summary> /// 具体的产品 /// </summary> public class SqlServerUser: IDatabaseUser { public void InsertUser(User user) { Console.WriteLine($"插入了SqlServerUser:{user.Name}"); } public User GetUser(int id) { Console.WriteLine($"获取了Id：{id}的用户"); return null; } } /// <summary> /// 具体的产品 /// </summary> public class MysqlUser : IDatabaseUser { public void InsertUser(User user) { Console.WriteLine($"插入了MysqlUser:{user.Name}"); } public User GetUser(int id) { Console.WriteLine($"获取了Id：{id}的用户"); return null; } } /// <summary> /// 具体的产品 /// </summary> public class SqliteUser : IDatabaseUser { public void InsertUser(User user) { Console.WriteLine($"插入了SqliteUser:{user.Name}"); } public User GetUser(int id) { Console.WriteLine($"获取了Id：{id}的用户"); return null; } }
/// <summary> /// 部门类 /// </summary> public class Department { public string Name { get; set; } public int Id { get; set; } } /// <summary> /// 抽象的产品 /// </summary> public interface IDatabaseDepartment { void InsertDepartment(Department department); Department GetDepartment(int id); } /// <summary> /// 具体的产品 /// </summary> public class SqlServerDepartment : IDatabaseDepartment { public void InsertDepartment(Department department) { Console.WriteLine($"插入了SqlServerDepartment部门:{department.Name}"); } public Department GetDepartment(int id) { Console.WriteLine($"获取了Id：{id}的部门"); return null; } } /// <summary> /// 具体的产品 /// </summary> public class MysqlDepartment : IDatabaseDepartment { public void InsertDepartment(Department department) { Console.WriteLine($"插入了MysqlDepartment部门:{department.Name}"); } public Department GetDepartment(int id) { Console.WriteLine($"获取了Id：{id}的部门"); return null; } } /// <summary> /// 具体的产品 /// </summary> public class SqlliteDepartment : IDatabaseDepartment { public void InsertDepartment(Department department) { Console.WriteLine($"插入了SqlliteDepartment部门:{department.Name}"); } public Department GetDepartment(int id) { Console.WriteLine($"获取了Id：{id}的部门"); return null; } }
//C#控制台调用Console.WriteLine("抽象工厂");User user = new();user.Name = "mhg";user.Id = 1;//变化点IFacatory facatory=new SqlserverFacatory(); //MysqlFacatory //SqlliteFacatoryIDatabaseUser databaseUser = facatory.GetDatabaseUser();databaseUser.InsertUser(user);databaseUser?.GetUser(user.Id);Department department = new Department();department.Name = "研发部";department.Id = 2;IDatabaseDepartment databaseDepartment= facatory.GetDatabaseDepartment();databaseDepartment.InsertDepartment(department); databaseDepartment?.GetDepartment(department.Id);
以上就用抽象工厂实现的全部代码，该代码中IFacatory做为抽象工厂，SqlserverFacatory、MysqlFacatory、SqliteFacatory作为具体的产品工厂来生产产品；IDatabaseUser和IDatabaseDepartment为抽象的产品分别生产具体的产品SqlServerUser、MysqlUser、SqliteUser和SqlServerDepartment、MysqlDepartment、SqlliteDepartment。
总结
这个需求也可以用工厂模式实现，但每增加一个产品，就必须增加一个工厂类，而用抽象工厂可以缩减创建子类工厂的数量，不必给每一个产品增加工厂类，可以对产品进行分组，每组中的不同产品由同一个工厂类的不同方法来创建。
