public static string MD5Encrypt(string strText)

    {

        MD5 md5 = MD5.Create();

        byte[] fromData = Encoding.Default.GetBytes(strText);

        byte[] targetData = md5.ComputeHash(fromData);

        StringBuilder byte2String = new StringBuilder();

        for (int i = 0; i < targetData.Length; i++)

        {

            byte2String.AppendFormat("{0:x2}", targetData[i]);

        }

        return byte2String.ToString();

    }