第一章 代码无错就是优吗？(简单工厂模式)
今天是设计模式的第一章由于工作比较忙所以一直想写点什么,但是还是没时间写。这篇的主题是代码无错可以运行就是优质代码吗？
首先要实现一个业务代码:有部门A,B,C,D 四个部门但是A部门的奖金是10%,B部门的是20%,C部门是30%,D部门的是40% 编写一段代码实现输入底薪后计算出最后薪水
class Program
{
static void Main(string[] args)
{
Console.WriteLine("请输入底薪：");
int a =Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入部门：");
string b = Console.ReadLine();
string d = String.Empty;
if (b == "a")
{
d = (a * 0.1 + a).ToString();
}
if (b == "b")
{
d = (a * 0.2 + a).ToString();
}
if (b == "c")
{
d = (a * 0.3 + a).ToString();
}
if (b == "d")
{
d = (a * 0.4 + a).ToString();
}
Console.WriteLine("您的薪水是：{0}RMB",d);
Console.ReadKey();
}
}
先看上面的代码,复制运行下看看。
没问题吧需求的业务功能都实现了。但是这样的代码真的好吗？
首先临界值的问题放在一边不说：
项目大了这样的命名自己都搞不清楚这个变量是什么用的了,就像是给软件埋了几个地雷,谁来改谁就踩了地雷了。那么来改改？
class Program
{
static void Main(string[] args)
{
Console.WriteLine("请输入底薪：");
int BasicSalary =Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入部门：");
string Department = Console.ReadLine();
string Salary = String.Empty;
switch (Department)
{
case "a" :
Salary = (BasicSalary * 0.1 + BasicSalary).ToString();
break;
case "b":
Salary = (BasicSalary * 0.2 + BasicSalary).ToString();
break;
case "c":
Salary = (BasicSalary * 0.3 + BasicSalary).ToString();
break;
case "d":
Salary = (BasicSalary * 0.4 + BasicSalary).ToString();
break;
default:
break;
}
Console.WriteLine("您的薪水是：{0}RMB",Salary);
Console.ReadKey();
}
}
这样行了吗？修改了命名修改了用switch代替if减少判断次数。哈哈你看到下面还有篇幅就猜到还不行。
这样的代码没有面向对象复用性很差 解决的办法是业务的封装再来改改
class Program
{
static void Main(string[] args)
{
Console.WriteLine("请输入底薪：");
int BasicSalary = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入部门：");
string Department = Console.ReadLine();
Console.WriteLine("您的薪水是：{0}RMB", GetResult(Department, BasicSalary));
Console.ReadKey();
}
public static string GetResult(string _department, int _basicsalary)
{
string Salary = String.Empty;
switch (_department)
{
case "a":
Salary = (_basicsalary * 0.1 + _basicsalary).ToString();
break;
case "b":
Salary = (_basicsalary * 0.2 + _basicsalary).ToString();
break;
case "c":
Salary = (_basicsalary * 0.3 + _basicsalary).ToString();
break;
case "d":
Salary = (_basicsalary * 0.4 + _basicsalary).ToString();
break;
default:
break;
}
return Salary;
}
}
嗯改了下业务和视图分开 这样Web,手机程序等等都可以调用这样业务逻辑就不用再Ctrl+C,在Ctrl+V了而且到后期业务逻辑修改了也不用再一个一个副本去修改了,改一下GetResult函数就可以咯。
我们继续 哈哈 还有啊...
如果今天公司发展和业务的需要加了一个部门f 那代码就需要修改业务代码了 破坏了代码的封装性 那怎么处理才是不破话封装呢。那就是面向对象的其他2个特性多态和继承
请看下面的代码:
public class Operation
{
private int basicsalary;
public int BasicSalary
{
get { return basicsalary; }
set { basicsalary = value; }
}
public virtual string GetResult()
{
string Salary = String.Empty;
return Salary;
}
}
class OperationA : Operation
{
public override string GetResult()
{
string Salary = String.Empty;
Salary = (BasicSalary * 0.1 + BasicSalary).ToString();
return Salary;
}
}
class OperationB : Operation
{
public override string GetResult()
{
string Salary = String.Empty;
Salary = (BasicSalary * 0.2 + BasicSalary).ToString();
return Salary;
}
}
class OperationC : Operation
{
public override string GetResult()
{
string Salary = String.Empty;
Salary = (BasicSalary * 0.3 + BasicSalary).ToString();
return Salary;
}
}
class OperationD : Operation
{
public override string GetResult()
{
string Salary = String.Empty;
Salary = (BasicSalary * 0.4 + BasicSalary).ToString();
return Salary;
}
}
class Program
{
static void Main(string[] args)
{
Console.WriteLine("请输入底薪：");
int BasicSalary = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入部门：");
string Department = Console.ReadLine();
Operation oper = OperationFactory.createOperate(Department);
oper.BasicSalary = BasicSalary;
Console.WriteLine("您的薪水是：{0}RMB", oper.GetResult());
Console.ReadKey();
}
}
public class OperationFactory
{
public static Operation createOperate(string operate)
{
Operation oper = null;
switch (operate)
{
case "a":
oper = new OperationA();
break;
case "b":
oper = new OperationB();
break;
case "c":
oper = new OperationC();
break;
case "d":
oper = new OperationD();
break;
default:
break;
}
return oper;
}
}
怎么样现在只要写一个运行对象然后加个new 就可以楼 不用去修改原来的业务逻辑噢。如果要修改界面就只要改界面的类楼。下面是UML图
吴蒋
2010.8.13
