编程时一门技术，更是一门艺术

简单工厂模式利用面向对象方式通过继承、封装、多态把程序的耦合度降低，设计模式使得程序更加灵活，容易修改，易于复用。

下面是服务器计算器代码：

复制代码 代码如下:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace DesignModel
{
/// <summary>
/// 计算器
/// </summary>
public class Calculator //创建一个计算器的基类可以接受两个参数，任何算法只需重写计算结果方法即可。
{
private double _numberA;
private double _numberB;
public double NumberA
{
get { return this._numberA; }
set { this._numberA = value; }
}
public double NumberB
{
get { return this._numberB; }
set { this._numberB = value; }
}
public virtual double GetResult()
{
double result = 0;
return result;
}
}
/// <summary>
/// 加法
/// </summary>
public class Add : Calculator //每添加一种计算方式只需添加一个计算类并重写基类方法即可
{
public override double GetResult()
{
return NumberA + NumberB;
}
}
/// <summary>
/// 减法
/// </summary>
public class Sub : Calculator
{
public override double GetResult()
{
return NumberA + NumberB;
}
}
/// <summary>
/// 计算器工厂
/// </summary>
public class CalculatorFactory
{
public static Calculator GetResult(string oper)
{
Calculator calcu = null;
switch (oper)
{
case "+":
calcu = new Add();
break;
case "-":
calcu = new Sub();
break;
}
return calcu;
}
}
}

复制代码 代码如下:
static void Main(string[] args)
{
Console.WriteLine("请输入数字A：");
string numbera = Console.ReadLine();
Console.WriteLine("请输入运算符：");
string oper = Console.ReadLine();
Console.WriteLine("请输入数字B：");
string numberb = Console.ReadLine();
Calculator c = CalculatorFactory.GetResult(oper);
c.NumberA = Convert.ToDouble(numbera);
c.NumberB = Convert.ToDouble(numberb);
Console.WriteLine(string.Format("{0}{1}{2}={3}", numbera, oper, numberb, c.GetResult()));
Console.ReadLine();
}

基本验证没加，学习练习的同学可以自己加上

28种设计模式后续更新

复制代码 代码如下:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace DesignModel
{
/// <summary>
/// 计算器
/// </summary>
public class Calculator //创建一个计算器的基类可以接受两个参数，任何算法只需重写计算结果方法即可。
{
private double _numberA;
private double _numberB;
public double NumberA
{
get { return this._numberA; }
set { this._numberA = value; }
}
public double NumberB
{
get { return this._numberB; }
set { this._numberB = value; }
}
public virtual double GetResult()
{
double result = 0;
return result;
}
}
/// <summary>
/// 加法
/// </summary>
public class Add : Calculator //每添加一种计算方式只需添加一个计算类并重写基类方法即可
{
public override double GetResult()
{
return NumberA + NumberB;
}
}
/// <summary>
/// 减法
/// </summary>
public class Sub : Calculator
{
public override double GetResult()
{
return NumberA + NumberB;
}
}
/// <summary>
/// 计算器工厂
/// </summary>
public class CalculatorFactory
{
public static Calculator GetResult(string oper)
{
Calculator calcu = null;
switch (oper)
{
case "+":
calcu = new Add();
break;
case "-":
calcu = new Sub();
break;
}
return calcu;
}
}
}

本文就是.net设计模式中的简单工厂模式的内容了，非常简单，下一篇，我们来谈谈策略模式