c#从四个数字创建唯一密钥并检查重复项

using System;
using System.Collections.Generic;

class Program
{
    static void Main(string[] args)
    {
        List<string> keys = new List<string>();

        while (true)
        {
            string key = GenerateUniqueKey();
            
            if (keys.Contains(key))
            {
                Console.WriteLine("重复的密钥：" + key);
            }
            else
            {
                keys.Add(key);
                Console.WriteLine("唯一的密钥：" + key);
            }
        }
    }

    static string GenerateUniqueKey()
    {
        Random random = new Random();
        int[] digits = new int[4];

        for (int i = 0; i < 4; i++)
        {
            digits[i] = random.Next(0, 10);
        }

        return string.Join("", digits);
    }
}