请问如何解决这个“system.Console”并不包含“ToDouble”的定义

Question

是  Convert.ToDouble(Console.ReadLine());不是Console

Answer 1

那是convert 不是console的方法~

Answer 2

Console.ToDouble====>Convert.ToDouble

Answer 3

你哪里摘抄的代码  Console么有.
应该是  Convert.ToDouble()

Answer 4

Convert.ToDouble
不是Console.ToDouble囧 粗心了 献丑了……

Answer 5

为何我每次执行到
Console.WriteLine("The result of subtracting{0}from{1}is{2].",
                secondNumber,firstNumber,firstNumber-secondNumber);
就出现
各位前辈求指导

Answer 6

郁闷，从网上把你们这一行的代码拷贝下来又能运行，我把它们加到一起了，怎么就会运行出现参数格式不正确，我仔细核对了，一模一样，代码如下，减法第二行为我的代码：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            double firstNumber, secondNumber;
            string userName;
            Console.WriteLine("Enter your name:");
            userName = Console.ReadLine();
            Console.WriteLine("Welcome {0}!", userName);
            Console.WriteLine("Now give me a number：");
            firstNumber = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("Now give me another number");
            secondNumber = Convert.ToDouble(Console.ReadLine());
            Console.WriteLine("The sum of {0} and {1} is {2}.",
                firstNumber, secondNumber, firstNumber + secondNumber);
            Console.WriteLine("The result of subtracting {0} from {1} is {2}.", 
                secondNumber, firstNumber, firstNumber - secondNumber);
            Console.WriteLine("The result of subtracting {0} from {1} is {2].",
                secondNumber, firstNumber, firstNumber - secondNumber);
            Console.WriteLine("The product of{0}and{1}is{2}",
                firstNumber, secondNumber, firstNumber * secondNumber);
            Console.WriteLine("The result of dividing{0}by{1}is{2}",
                firstNumber, secondNumber, firstNumber / secondNumber);
            Console.ReadKey();
        }
    }
}