Int To String And String To Int

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace IntToStringAndStringToInt
{
    class Program
    {
        /// <summary>
        /// int 转 string ,string 转 int
        /// </summary>
        /// <param name="args"></param>
        static void Main(string[] args)
        {
            int number = 98765432;
            intToString(number);
            string s = "556677889";
            stringToInt(s);          
            Console.ReadKey();
        }
        public static void intToString(int num)
        {
            string s = string.Empty;
            int a = 1;
            List<int> slist = new List<int>();
            while (true)
            {
                int mi = 1;
                for (int i = 0; i < a; i++)
                {
                    mi *= 10;
                }
                if (num * 10 / mi != 0)
                {
                    if (a == 1)
                    {
                        slist.Add(num % mi);
                    }
                    else
                    {
                        slist.Add((num % mi - num % (mi/10)) * 10 / mi);
                    }
                    a++;
                }
                else
                {
                    break;
                }
            }
            for (int j = slist.Count - 1; j >= 0; j--)
            {
                s += slist[j];
            }
                      
            Console.WriteLine(s);
        }

        public static void stringToInt(string s)
        {
            int sum = 0;
            for (int i = 0; i < s.Length; i++)
            {
                int a = s[i] - '0';//s[i]中是数字的char，所以-'0'就是转成对应的数字，如 '1'-'0'就是得到1
                sum = sum * 10 + a;

            }
            Console.WriteLine(sum);
        }
    }
}