/// <summary>
/// 根据用户输入，里氏转换方法，装载不同的子类
/// 简单工厂，根据用户对象返回一个父类
/// </summary>
/// <param name="numberOne"></param>
/// <param name="numberTwo"></param>
/// <param name="cal"></param>
/// <returns></returns>
public static CalFather GetResart(int numberOne, int numberTwo, string cal)
{
CalFather ft = null;
switch (cal)
{
case "+":
ft = new Sum(numberOne, numberTwo);
break;
case "-":
ft = new Sub(numberOne, numberTwo);
break;
}
return(ft);
}
static void Main(string[] args)
{
Console.WriteLine("请输入第1个数");
int numberOne = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入第2个数");
int numberTwo = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入运算符");
string cal = Console.ReadLine();
CalFather ft = GetResart(numberOne, numberTwo, cal);
double resut = ft.GetResut();
Console.WriteLine(resut);
Console.ReadKey();
}