encryptionAndDecryption/encryptionAndDecryption.cs

这里只显示每个文件的开头 60 行。登录后可以解锁完整代码。

微信扫码关注公众号，代码整理好后第一时间通知你。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;

namespace encryptionAndDecryption
{
    public enum DiscuzAuthcodeMode { Encode, Decode };

    public class Authcode
    {
        private static Encoding encoding = Encoding.GetEncoding("gbk");

        public Authcode()
        {
        }

        /// <summary>
        /// 从字符串的指定位置截取指定长度的子字符串
        /// </summary>
        /// <param name="str">原字符串</param>
        /// <param name="startIndex">子字符串的起始位置</param>
        /// <param name="length">子字符串的长度</param>
        /// <returns>子字符串</returns>
        private static string CutString(string str, int startIndex, int length)
        {
            if (startIndex >= 0)
            {
                if (length < 0)
                {
                    length = length * -1;
                    if (startIndex - length < 0)
                    {
                        length = startIndex;
                        startIndex = 0;
                    }
                    else
                    {
                        startIndex = startIndex - length;
                    }
                }

                if (startIndex > str.Length)
                {
                    return "";
                }
            }
            else
            {
                if (length < 0)
                {
                    return "";
                }
                else
                {
                    if (length + startIndex > 0)
                    {
                        length = length + startIndex;
                        startIndex = 0;