软件设计模式之工厂模式实验
一、实验目的
掌握软件设计模式中的工厂模式,能够用工厂模式编写程序,解决实际问题。
二、实验内容与要求
内容:使用工厂模式写一个简单的计算器,能实现加减乘除运算。要求输入两个数,选择运算符,程序便能够计算出结果。程序设计语言可自由选择。
要求:需要用“文字+代码+截图”的形式对实验的主要代码和运行结果进行展示和描述。
三、实验方法
- Operation运算类(父类):
public class Operation
{
private double _numberA = 0;
private double _numberB = 0;
public double NumberA
{
get { return _numberA; }
set { _numberA = value;}
}
public double NumberB
{
get { return _numberB; }
set { _numberB = value;}
}
public virtual double GetResult()
{
double result = 0;
return result;
}
}
- 加减乘除类:
class OperationAdd : Operation
{
public override double GetResult()
{
double result = 0;
result = NumberA + NumberB;
return result;
}
}
class OperationSub : Operation
{
public override double GetResult()
{
double result = 0;
result = NumberA - NumberB;
return result;
}
}
class OperationMul : Operation
{
public override double GetResult()
{
double result = 0;
result = NumberA * NumberB;
return result;
}
}
class OperationDiv : Operation
{
public override double GetResult()
{
double result = 0;
if (NumberB == 0)
throw new Exception("除数不能为0。");
result = NumberA / NumberB;
return result;
}
}
- 简单运算工厂类:
public class OperationFactory
{
public static Operation createOperate(string operate)
{
Operation oper = null;
switch (operate)
{
case "+":
oper = new OperationAdd();
break;
case "-":
oper = new OperationSub();
break;
case "*":
oper = new OperationMul();
break;
case "/":
oper = new OperationDiv();
break;
}
return oper;
}
}
四 、实验结果
简单来说就是创建一个单独的工厂类专门实例化出合适的对象,当然加减乘除类也采用了松耦合,通过多态,返回父类的方式实现了计算器的结果,具备可扩展性。