如何捕获不符合枚举参数的输入？C#枚举输入异常处理

嘿，我懂你遇到的麻烦了——现在输入1-7以外的数字程序直接终止，核心问题有两个：一是你的代码里没添加对应catch块捕获Enum.Parse抛出的异常，二是默认枚举值从0开始，输入1会对应Tuesday，和你预期的“1=周一”不符。下面是调整后的完整解决方案：

步骤1：修正枚举的数值映射 #

先给每个星期成员指定对应数字，确保输入1对应Monday，7对应Sunday：

public enum EDay
{
    Monday = 1,
    Tuesday = 2,
    Wednesday = 3,
    Thursday = 4,
    Friday = 5,
    Saturday = 6,
    Sunday = 7
}

步骤2：添加异常捕获逻辑 #

在try块后添加catch块，捕获Enum.Parse抛出的ArgumentException（输入无法解析为有效枚举值时触发），同时给用户友好提示，甚至可以支持重新输入：

namespace DaysOfTheWeek
{
    class Program
    {
        public enum EDay
        {
            Monday = 1,
            Tuesday = 2,
            Wednesday = 3,
            Thursday = 4,
            Friday = 5,
            Saturday = 6,
            Sunday = 7
        }

        static void Main(string[] args)
        {
            try
            {
                Console.WriteLine("Hello! A week has 7 days! What day of this week is it?");
                // 读取输入并解析为枚举，忽略大小写
                EDay pickDay = (EDay)Enum.Parse(typeof(EDay), Console.ReadLine(), true);
                Console.WriteLine($"You picked: {pickDay}");
            }
            catch (ArgumentException ex)
            {
                // 处理无效输入场景
                Console.WriteLine("Oops! Please enter a number between 1 and 7 (inclusive) to represent the day of the week.");
                // 可选：让用户重新输入，递归调用Main即可
                // Main(args);
            }
        }
    }
}

额外优化：更高效的输入验证（可选） #

如果不想依赖异常处理做验证，也可以先把输入转成整数，判断范围后再转枚举，这样性能更优：

static void Main(string[] args)
{
    Console.WriteLine("Hello! A week has 7 days! What day of this week is it?");
    string input = Console.ReadLine();
    if (int.TryParse(input, out int dayNum))
    {
        if (dayNum >= 1 && dayNum <=7)
        {
            EDay pickDay = (EDay)dayNum;
            Console.WriteLine($"You picked: {pickDay}");
        }
        else
        {
            Console.WriteLine("Please enter a number between 1 and 7!");
        }
    }
    else
    {
        Console.WriteLine("Invalid input! Please enter a valid number.");
    }
}

这样不管输入非数字还是超出范围的数字，程序都能友好处理，不会直接终止啦。

内容的提问来源于stack exchange，提问作者Carter