简单工厂模式(Simple Factory Pattern)
简单工厂模式定义一个类来负责创建其他类的实例，被创建的实例通常都具有共同的父类。因为在简单工厂模式中用于创建实例的方法是静态（static）方法，又叫做静态工厂方法（Static Factory Method）模式，简单工厂模式是属于创建型模式。
using System;namespace ConsoleApplication{ //一般每个接口或类都写在单独的.cs文件中 //本示例为了执行查看方便才写在一起 public interface Database { void Delete(); void Insert(); } //Sqlserver的增删 public class Sqlserver : Database { public void Delete() { Console.WriteLine("delete data from sqlserver"); } public void Insert() { Console.WriteLine("insert data to sqlserver"); } } //Mysql的增删 public class Mysql : Database { public void Delete() { Console.WriteLine("delete data from Mysql"); } public void Insert() { Console.WriteLine("insert data to Mysql"); } } public static class IFactory { //根据需求创建 public static Database CreateDatabase(string dbType) { Database db = null; switch (dbType) { case "Sqlserver": db = new Sqlserver(); break; case "Mysql": db = new Mysql(); break; default: break; } return db; } } class Program { static void Main(string[] args) { Database db1 = IFactory.CreateDatabase("Sqlserver"); db1.Delete(); db1.Insert(); Database db2 = IFactory.CreateDatabase("Mysql"); db2.Delete(); db2.Insert(); Console.ReadKey(); Console.ReadKey(); } }}