static void Main(string[] args)
{
//虚方法、抽象类、接口
//面向对象计算器 案例
Console.WriteLine("请输入第一个数字：");
double n1 = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("请输入第二个数字：");
double n2 = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("请输入操作符：");
string opera = Console.ReadLine();
CalFather cal = GetCal(opera, n1, n2);
double result = cal.Calculator();
Console.WriteLine(result);
Console.ReadKey();
}
public static CalFather GetCal(string opera, double n1, double n2)
{
CalFather cal = null;
switch (opera)
{
case "+":
cal = new Plus(n1, n2);
break;
case "-":
cal = new Minus(n1, n2);
break;
case "*":
cal = new Multiply(n1, n2);
break;
case "/":
cal = new Divide(n1, n2);
break;
}
return(cal);
}