这是课程6中更改后的，原文显示的有些看不懂

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

//using static System.Console;

//using static System.Convert;

namespace Ch06Ex05

{

class Program

{

delegate double ProcessDelegate(double param1, double param2);

/******

原文是：

static double Multiply(double param1, double param2) => param1 * param2;

static double Divide(double param1, double param2) => param1 / param2;

注：这个编译报错VS2013

*********/

修改后的是：

static double Multiply(double param1, double param2)

{

return param1 * param2;

}

static double Divide(double param1, double param2)

{

return param1 / param2;

}

这个正常，请问是什么原因呢？

 

static void Main(string[] args)

{

ProcessDelegate process;

Console.WriteLine("Enter 2 numbers separated with a comma:");

string input = Console.ReadLine();

int commaPos = input.IndexOf(',');

double param1 = Convert.ToDouble(input.Substring(0, commaPos));

double param2 = Convert.ToDouble(input.Substring(commaPos + 1,

input.Length - commaPos - 1));

Console.WriteLine("Enter M to multiply or D to divide:");

input = Console.ReadLine();

if (input == "M")

process = new ProcessDelegate(Multiply);

else

process = new ProcessDelegate(Divide);

Console.WriteLine("Result: {0}", process(param1, param2));

Console.ReadKey();

}

}

}