无法声明局部变量名称'choice',因为它会给'choice'赋予不同的含义

Question

对不起,我是编程世界的新手.我正在创建一个控制台应用程序,基本上可以输入您是否要将摄氏温度转换为华氏温度,反之亦然.

我遇到的问题是:

"错误3无法在此范围内声明名为'choice'的局部变量,因为它会给'choice'赋予不同的含义,'choice'已在'parent或current'范围内用于表示其他内容"

我试着看其他例子,但它们远比我大脑现在所能理解的要复杂得多.

namespace TemperatureApp
{
    class Program
    {
        static void Main(string[] args)
        {
            int choice;

            do
            {
                Console.WriteLine("Hi! This is a temperatue app");
                Console.WriteLine("Press 1 for C to F or 2 for F to C");
                //take the user input
                int choice = Convert.ToInt32(Console.ReadLine());


                if (choice == 1)
                {
                    Console.WriteLine("Great, you chose C to F. Now enter the temp.");
                    int celcius = Convert.ToInt32(Console.ReadLine());
                    //next line use the formula and show answer
                }
                if (choice == 2)
                {
                    Console.WriteLine("Great, you chose F to C. Now enter the temp.");
                    int fahrenheit = Convert.ToInt32(Console.ReadLine());
                    //next line use the formula and show answer
                }
                else
                    Console.WriteLine("That is not the right choice.");
                    //In this way, keep asking the person for either 1 or two

            }
            while (choice != 1 || choice != 2);

            Console.ReadLine();
        }
    }
}

Answer 1

int choice = Convert.ToInt32(Console.ReadLine());

应该读

choice = Convert.ToInt32(Console.ReadLine());

通过int第二次放置,您在{}内声明另一个名为"choice"的变量.这个定义与外面的定义相冲突.