C# 后台处理字符串如何+1

Question

例如：1、字符串“AB0021”，末尾+1，变成“AB0022”。2、字符串“AZ9999”，末尾+1，变成“BA0000”。

Answer 1

题主要的代码如下

using System;
using System.Text.RegularExpressions;
namespace ConsoleApp1
{
    class Program
    {
        public static string AddOne(string s)
        {
            s = s.ToUpper();
            Regex re = new Regex(@"^([A-Z]*)(\d+)$", RegexOptions.Compiled);
            if (string.IsNullOrEmpty(s) || !re.IsMatch(s)) return "输入格式有误，请输入字母开头数字结尾的字符串";
            Match m = re.Match(s);
            string sChar = m.Groups[1].Value;

            int num = int.Parse(m.Groups[2].Value.TrimStart('0'));
            int numLen = m.Groups[2].Value.Length;
            num += 1;

            if (num.ToString().Length > numLen)
            {
                num = 0;
                if (sChar == "") sChar = "A";
                else
                {
                    int index = sChar.Length - 1;
                    var arr = sChar.ToCharArray();
                    bool flag = false;
                    while (index >= 0)
                    {
                        var c = arr[index];
                        if (c != 'Z')
                        {
                            flag = false;
                            arr[index] = (char)(int)(sChar[index] + 1);
                            break;
                        }
                        else
                        {
                            arr[index] = 'A';
                            flag = true;
                        }

                        index--;
                    }
                    sChar = (flag ? "A" : "") + string.Join("", arr);
                }
            }
            s = sChar + num.ToString().PadLeft(numLen, '0');
            return s;
        }

        static void Main(string[] args)
        {
            Console.WriteLine(AddOne("AB998"));
            Console.WriteLine(AddOne("AB0021"));
            Console.WriteLine(AddOne("AZ9999"));
            Console.WriteLine(AddOne("ZZ9999"));
            Console.WriteLine(AddOne("ZAZ9999"));

            Console.ReadKey();
        }


    }
}