C#生成推广邀请码

需求描述

1）根据用户id生成唯一邀请码；

2）根据邀请码反推用户id；

主要步骤

1）设置邀请码位数len，自定义乱序字符串sourcecode，用户id；

注：乱序字符串增加其安全性；剔除sourcecode中的补位“0”和易混淆的“I，O”；

2）将用户id进行十六进制转换；

3）对转换后的字符串高位补零；

4）间隔插入随机字符；

代码实现

using System;

namespace invitedCode
{
    class Program
    {
        static void Main(string[] args)
        {
            int len = 10;    //code偶数位

            //自定义乱序字符串,‘0-9 A-Z’,剔除易混淆字符‘I，O’，剔除高位补‘0’
            string sourcecode = "MWX89FCDG3J2RS1TUKLYZE5V67HQA4BNP";     
            int uid = 12345;      //用户id

            string code = CreateCode(len,sourcecode, uid);
            string decode = Decode(code);

            Console.WriteLine(code);
            Console.WriteLine(decode);

            Console.ReadKey();
        }

        private static string Decode(string code)
        {
            //提取用户id
            string str = "";
            string uid = "";
            for (int i = 0; i < code.Length; i += 2)
            {
                str += code.Substring(i, 1);
            }
            //剔除高位零
            for (int i = 0; i < str.Length; i++)
            {
                if (!str.Substring(i, 1).Equals("0"))
                {
                    str = str.Substring(i, str.Length - i);
                    break;
                }
            }
            uid = Convert.ToInt32(str, 16).ToString();

            return uid;
        }

        private static string CreateCode(int len, string sourcecode, int uid)
        {
            //十进制转十六进制
            string hexid = Convert.ToString(uid,16);

            //高位补零
            string str = "";

            for (int i = len/2; i > hexid.Length; i--)
            {
                str += "0";
            }
            str += hexid;

            //插入随机字符

            Random ran = new Random();
            for (int i = 1; i < str.Length+1; i += 2)
            {
                str = str.Insert(i, sourcecode.Substring(ran.Next(0, sourcecode.Length-1), 1));
            }
            return str;
        }
    }
}