MD5散列算法(单项加密)
　　必须引入System.Security.Cryptography 命名空间
/// <summary>
/// 功能：MD5散列算法
/// </summary>
/// <param name="inputStr">参数：待加密的字符串</param>
/// <param name="secString">参数：特殊加密字符串</param>
/// <returns>返回值：加密后的密文(大写)，string类型</returns>
public static string GetMd5Str(string inputStr， string secString)
{
byte[] palinData = null;
byte[] encryptData = null;
try
{
MD5 md5 = new MD5CryptoServiceProvider();
palinData = Encoding.Default.GetBytes(inputStr + secString);
encryptData = md5.ComputeHash(palinData);
}
catch (Exception e)
{
throw e;
}
return Convert.ToBase64String(encryptData).Substring(0， 20).ToUpper();
}