简单工厂模式

using System;

//简单工厂模式
namespace MyConsoleApplication
{
/// <summary>
/// 运算类
/// </summary>
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;
}
}

/// <summary>
/// 加法类
/// </summary>
class OperationAdd : Operation
{
public override double GetResult()
{
double result = 0;
result = NumberA + NumberB;
return result;
}
}
/// <summary>
/// 减法类
/// </summary>
class OperationSub : Operation
{
public override double GetResult()
{
double result = 0;
result = NumberA - NumberB;
return result;
}
}
/// <summary>
/// 乘法类
/// </summary>
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;
}
}

class OperationFactory
{
public static Operation createOperation(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;
}
}

class Program
{
static void Main(string[] args)
{
Operation oper;
Console.Write("请输入运算符:");
var opers = Console.ReadLine().ToString();
Console.Write("请输入第一个数:");
var a = Convert.ToDouble(Console.ReadLine());
Console.Write("请输入第二个数:");
var b = Convert.ToDouble(Console.ReadLine());
oper = OperationFactory.createOperation(opers);
oper.NumberA = a;
oper.NumberB = b;
var result = "运算结果为:" + oper.GetResult();
Console.WriteLine(result);
Console.ReadLine();
}
}
}