这篇文章主要介绍了C#常用字符串加密解密方法封装代码，有需要的朋友可以参考一下

   代码如下: //方法一 //须添加对System.Web的引用 //using System.Web.Security; /// <summary> /// SHA1加密字符串 /// </summary> /// <param name="source">源字符串</param> /// <returns>加密后的字符串</returns> public string SHA1(string source) {     return FormsAuthentication.HashPasswordForStoringInConfigFile(source, "SHA1"); } /// <summary> /// MD5加密字符串 /// </summary> /// <param name="source">源字符串</param> /// <returns>加密后的字符串</returns> public string MD5(string source) {     return FormsAuthentication.HashPasswordForStoringInConfigFile(source, "MD5");; }     //方法二(可逆加密解密)： //using System.Security.Cryptography; public string Encode(string data) {     byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);     byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);     DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();     int i = cryptoProvider.KeySize;     MemoryStream ms = new MemoryStream();     CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write);     StreamWriter sw = new StreamWriter(cst);     sw.Write(data);     sw.Flush();     cst.FlushFinalBlock();     sw.Flush();     return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length); } public string Decode(string data) {     byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);     byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);     byte[] byEnc;     try     {         byEnc = Convert.FromBase64String(data);     }     catch     {         return null;     }     DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();     MemoryStream ms = new MemoryStream(byEnc);     CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read);     StreamReader sr = new StreamReader(cst);     //方法三(MD5不可逆)： //using System.Security.Cryptography; //MD5不可逆加密 //32位加密 public string GetMD5_32(string s, string _input_charset) {     MD5 md5 = new MD5CryptoServiceProvider();     byte[] t = md5.ComputeHash(Encoding.GetEncoding(_input_charset).GetBytes(s));     StringBuilder sb = new StringBuilder(32);     for (int i = 0; i < t.Length; i++)     {         sb.Append(t[i].ToString("x").PadLeft(2, '0'));     }     return sb.ToString(); } //16位加密 public static string GetMd5_16(string ConvertString) {     MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();     string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);     t2 = t2.Replace("-", "");     return t2; }     //方法四(对称加密)： //using System.IO; //using System.Security.Cryptography; private SymmetricAlgorithm mobjCryptoService; private string Key; /// <summary>    /// 对称加密类的构造函数    /// </summary>    public SymmetricMethod() {     mobjCryptoService = new RijndaelManaged();     Key = "Guz(%&hj7x89H$yuBI0456FtmaT5&fvHUFCy76*h%(HilJ$lhj!y6&(*jkP87jH7"; } /// <summary>    /// 获得密钥    /// </summary>    /// <returns>密钥</returns>    private byte[] GetLegalKey() {     string sTemp = Key;     mobjCryptoService.GenerateKey();     byte[] bytTemp = mobjCryptoService.Key;     int KeyLength = bytTemp.Length;     if (sTemp.Length > KeyLength)         sTemp = sTemp.Substring(0, KeyLength);     else if (sTemp.Length < KeyLength)         sTemp = sTemp.PadRight(KeyLength, ' ');     return ASCIIEncoding.ASCII.GetBytes(sTemp); } /// <summary>    /// 获得初始向量IV    /// </summary>    /// <returns>初试向量IV</returns>    private byte[] GetLegalIV() {     string sTemp = "E4ghj*Ghg7!rNIfb&95GUY86GfghUb#er57HBh(u%g6HJ($jhWk7&!hg4ui%$hjk";     mobjCryptoService.GenerateIV();     byte[] bytTemp = mobjCryptoService.IV;     int IVLength = bytTemp.Length;     if (sTemp.Length > IVLength)         sTemp = sTemp.Substring(0, IVLength);     else if (sTemp.Length < IVLength)         sTemp = sTemp.PadRight(IVLength, ' ');     return ASCIIEncoding.ASCII.GetBytes(sTemp); } /// <summary>    /// 加密方法    /// </summary>    /// <param name="Source">待加密的串</param>    /// <returns>经过加密的串</returns>    public string Encrypto(string Source) {     byte[] bytIn = UTF8Encoding.UTF8.GetBytes(Source);     MemoryStream ms = new MemoryStream();     mobjCryptoService.Key = GetLegalKey();     mobjCryptoService.IV = GetLegalIV();     ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();     CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);     cs.Write(bytIn, 0, bytIn.Length);     cs.FlushFinalBlock();     ms.Close();     byte[] bytOut = ms.ToArray();     return Convert.ToBase64String(bytOut); } /// <summary>    /// 解密方法    /// </summary>    /// <param name="Source">待解密的串</param>    /// <returns>经过解密的串</returns>    public string Decrypto(string Source) {     byte[] bytIn = Convert.FromBase64String(Source);     MemoryStream ms = new MemoryStream(bytIn, 0, bytIn.Length);     mobjCryptoService.Key = GetLegalKey();     mobjCryptoService.IV = GetLegalIV();     ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();     CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);     StreamReader sr = new StreamReader(cs);     return sr.ReadToEnd(); }   //方法五： //using System.IO; //using System.Security.Cryptography; //using System.Text; //默认密钥向量 private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF }; /**//**//**//// <summary> /// DES加密字符串 keleyi.com /// </summary> /// <param name="encryptString">待加密的字符串</param> /// <param name="encryptKey">加密密钥,要求为8位</param> /// <returns>加密成功返回加密后的字符串，失败返回源串</returns> public static string EncryptDES(string encryptString, string encryptKey) {     try     {         byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));         byte[] rgbIV = Keys;         byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);         DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();         MemoryStream mStream = new MemoryStre