using System;using System.Configuration;using System.Collections.Generic;using System.Text;using System.Web;using System.Web.UI;using System.Web.UI.HtmlControls;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.Security;using System.Drawing;using System.Drawing.Imaging;using System.Drawing.Drawing2D;using System.IO;using System.Security.Cryptography; namespace Utils{    /// <summary>    /// <para>　</para>    /// 　常用工具类——加密解密类    /// <para>　-------------------------------------------------</para>    /// <para>　StringEncode：返回 HTML 字符串的编码结果</para>    /// <para>　StringDecode：返回 HTML 字符串的解码结果</para>    /// <para>　UrlEncode：返回 URL 字符串的编码结果</para>    /// <para>　UrlDecode：返回 URL 字符串的解码结果</para>    /// <para>　DESEncrypt：DES加密</para>    /// <para>　DESDecrypt：DES解密</para>    /// <para>　MD5：MD5函数</para>    /// <para>　SHA256：SHA256函数</para>    /// </summary>    public class EncyptHelper    {        /// <summary>        /// 32位Key值：        /// </summary>        public static byte[] DESKey = new byte[] { 0x03, 0x0B, 0x13, 0x1B, 0x23, 0x2B, 0x33, 0x3B, 0x43, 0x4B, 0x9B, 0x93, 0x8B, 0x83, 0x7B, 0x73, 0x6B, 0x63, 0x5B, 0x53, 0xF3, 0xFB, 0xA3, 0xAB, 0xB3, 0xBB, 0xC3, 0xEB, 0xE3, 0xDB, 0xD3, 0xCB };         #region 返回 HTML 字符串的编码结果        /// <summary>        /// 返回 HTML 字符串的编码结果        /// </summary>        /// <param name="str">字符串</param>        /// <returns>编码结果</returns>        public static string StringEncode(string str)        {            return HttpUtility.HtmlEncode(str);        }        #endregion         #region 返回 HTML 字符串的解码结果        /// <summary>        /// 返回 HTML 字符串的解码结果        /// </summary>        /// <param name="str">字符串</param>        /// <returns>解码结果</returns>        public static string StringDecode(string str)        {            return HttpUtility.HtmlDecode(str);        }        #endregion         #region 返回 URL 字符串的编码结果        /// <summary>        /// 返回 URL 字符串的编码结果        /// </summary>        /// <param name="str">字符串</param>        /// <returns>编码结果</returns>        public static string UrlEncode(string str)        {            return HttpUtility.UrlEncode(str);        }        #endregion         #region 返回 URL 字符串的解码结果        /// <summary>        /// 返回 URL 字符串的解码结果        /// </summary>        /// <param name="str">字符串</param>        /// <returns>解码结果</returns>        public static string UrlDecode(string str)        {            return HttpUtility.UrlDecode(str);        }        #endregion         #region DES加密        /// <summary>        /// DES加密        /// </summary>        /// <param name="strSource">待加密字串</param>        /// <returns>加密后的字符串</returns>        public static string DESEncrypt(string strSource)        {            return DESEncrypt(strSource, DESKey);        }        /// <summary>        /// DES加密        /// </summary>        /// <param name="strSource">待加密字串</param>        /// <param name="key">Key值</param>        /// <returns>加密后的字符串</returns>        public static string DESEncrypt(string strSource, byte[] key)        {            SymmetricAlgorithm sa = Rijndael.Create();            sa.Key = key;            sa.Mode = CipherMode.ECB;            sa.Padding = PaddingMode.Zeros;            MemoryStream ms = new MemoryStream();            CryptoStream cs = new CryptoStream(ms, sa.CreateEncryptor(), CryptoStreamMode.Write);            byte[] byt = Encoding.Unicode.GetBytes(strSource);            cs.Write(byt, 0, byt.Length);            cs.FlushFinalBlock();            cs.Close();            return Convert.ToBase64String(ms.ToArray());        }        #endregion         #region DES解密        /// <summary>        /// DES解密        /// </summary>        /// <param name="strSource">待解密的字串</param>        /// <returns>解密后的字符串</returns>        public static string DESDecrypt(string strSource)        {            return DESDecrypt(strSource, DESKey);        }        /// <summary>        /// DES解密        /// </summary>        /// <param name="strSource">待解密的字串</param>        /// <param name="key">32位Key值</param>        /// <returns>解密后的字符串</returns>        public static string DESDecrypt(string strSource, byte[] key)        {            SymmetricAlgorithm sa = Rijndael.Create();            sa.Key = key;            sa.Mode = CipherMode.ECB;            sa.Padding = PaddingMode.Zeros;            ICryptoTransform ct = sa.CreateDecryptor();            byte[] byt = Convert.FromBase64String(strSource);            MemoryStream ms = new MemoryStream(byt);            CryptoStream cs = new CryptoStream(ms, ct, CryptoStreamMode.Read);            StreamReader sr = new StreamReader(cs, Encoding.Unicode);            return sr.ReadToEnd();        }        #endregion                 #region MD5函数        /// <summary>        /// MD5函数,需引用：using System.Security.Cryptography;        /// </summary>        /// <param name="str">原始字符串</param>        /// <returns>MD5结果</returns>        public static string MD5(string str)        {            byte[] b = Encoding.Default.GetBytes(str);            b = new MD5CryptoServiceProvider().ComputeHash(b);            string ret = "";            for (int i = 0; i < b.Length; i++)                ret += b[i].ToString("x").PadLeft(2, ‘0‘);            return ret;        }        #endregion         #region SHA256函数        /// <summary>        /// SHA256函数        /// </summary>        /// /// <param name="str">原始字符串</param>        /// <returns>SHA256结果</returns>        public static string SHA256(string str)        {            byte[] SHA256Data = http://www.mamicode.com/Encoding.UTF8.GetBytes(str);>