/// <summary>
        /// Base64解密
        /// </summary>
        /// <param name="text">要解密的字符串</param>
        public static string DecodeBase64(string text)
        {
            //如果字符串为空,则返回
            if (StringValidate.IsNullOrEmpty <string>(text))
            {
                return("");
            }

            //将空格替换为加号
            text = text.Replace(" ", "+");

            try
            {
                if ((text.Length % 4) != 0)
                {
                    return("包含不正确的BASE64编码");
                }
                if (!Regex.IsMatch(text, "^[A-Z0-9/+=]*$", RegexOptions.IgnoreCase))
                {
                    return("包含不正确的BASE64编码");
                }
                string    Base64Code = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
                int       page       = text.Length / 4;
                ArrayList outMessage = new ArrayList(page * 3);
                char[]    message    = text.ToCharArray();
                for (int i = 0; i < page; i++)
                {
                    byte[] instr = new byte[4];
                    instr[0] = (byte)Base64Code.IndexOf(message[i * 4]);
                    instr[1] = (byte)Base64Code.IndexOf(message[i * 4 + 1]);
                    instr[2] = (byte)Base64Code.IndexOf(message[i * 4 + 2]);
                    instr[3] = (byte)Base64Code.IndexOf(message[i * 4 + 3]);
                    byte[] outstr = new byte[3];
                    outstr[0] = (byte)((instr[0] << 2) ^ ((instr[1] & 0x30) >> 4));
                    if (instr[2] != 64)
                    {
                        outstr[1] = (byte)((instr[1] << 4) ^ ((instr[2] & 0x3c) >> 2));
                    }
                    else
                    {
                        outstr[2] = 0;
                    }
                    if (instr[3] != 64)
                    {
                        outstr[2] = (byte)((instr[2] << 6) ^ instr[3]);
                    }
                    else
                    {
                        outstr[2] = 0;
                    }
                    outMessage.Add(outstr[0]);
                    if (outstr[1] != 0)
                    {
                        outMessage.Add(outstr[1]);
                    }
                    if (outstr[2] != 0)
                    {
                        outMessage.Add(outstr[2]);
                    }
                }
                byte[] outbyte = (byte[])outMessage.ToArray(Type.GetType("System.Byte"));
                return(Encoding.Default.GetString(outbyte));
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        /// <summary>
        /// Base64加密
        /// </summary>
        /// <param name="text">要加密的字符串</param>
        /// <returns></returns>
        public static string EncodeBase64(string text)
        {
            //如果字符串为空,则返回
            if (StringValidate.IsNullOrEmpty <string>(text))
            {
                return("");
            }

            try
            {
                char[] Base64Code = new char[] { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
                                                 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
                                                 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',
                                                 '8', '9', '+', '/', '=' };
                byte          empty       = (byte)0;
                ArrayList     byteMessage = new ArrayList(Encoding.Default.GetBytes(text));
                StringBuilder outmessage;
                int           messageLen = byteMessage.Count;
                int           page       = messageLen / 3;
                int           use        = 0;
                if ((use = messageLen % 3) > 0)
                {
                    for (int i = 0; i < 3 - use; i++)
                    {
                        byteMessage.Add(empty);
                    }
                    page++;
                }
                outmessage = new System.Text.StringBuilder(page * 4);
                for (int i = 0; i < page; i++)
                {
                    byte[] instr = new byte[3];
                    instr[0] = (byte)byteMessage[i * 3];
                    instr[1] = (byte)byteMessage[i * 3 + 1];
                    instr[2] = (byte)byteMessage[i * 3 + 2];
                    int[] outstr = new int[4];
                    outstr[0] = instr[0] >> 2;
                    outstr[1] = ((instr[0] & 0x03) << 4) ^ (instr[1] >> 4);
                    if (!instr[1].Equals(empty))
                    {
                        outstr[2] = ((instr[1] & 0x0f) << 2) ^ (instr[2] >> 6);
                    }
                    else
                    {
                        outstr[2] = 64;
                    }
                    if (!instr[2].Equals(empty))
                    {
                        outstr[3] = (instr[2] & 0x3f);
                    }
                    else
                    {
                        outstr[3] = 64;
                    }
                    outmessage.Append(Base64Code[outstr[0]]);
                    outmessage.Append(Base64Code[outstr[1]]);
                    outmessage.Append(Base64Code[outstr[2]]);
                    outmessage.Append(Base64Code[outstr[3]]);
                }
                return(outmessage.ToString());
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }