c# AES加解密并转ASCII码

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace AESDecryptDemo
{
   public class AES
    {
       public static string AESEncryptASCII(string plainStr)
       {
           StringBuilder sb = new StringBuilder();
           byte[] bKey = Encoding.UTF8.GetBytes(GetKey());
           byte[] bIV = Encoding.UTF8.GetBytes(GetIV());
           byte[] byteArray = Encoding.UTF8.GetBytes(plainStr);

           string encrypt = null;
           Rijndael aes = Rijndael.Create();
           using (MemoryStream mStream = new MemoryStream())
           {
               using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateEncryptor(bKey, bIV), CryptoStreamMode.Write))
               {
                   cStream.Write(byteArray, 0, byteArray.Length);
                   cStream.FlushFinalBlock();
                   encrypt = Encode(Convert.ToBase64String(mStream.ToArray()));
               }
           }
           aes.Clear();
           return encrypt;
       }
       public static string AESEncrypt(string plainStr)
       {
           StringBuilder sb = new StringBuilder();
           byte[] bKey = Encoding.UTF8.GetBytes(GetKey());
           byte[] bIV = Encoding.UTF8.GetBytes(GetIV());
           byte[] byteArray = Encoding.UTF8.GetBytes(plainStr);

           string encrypt = null;
           Rijndael aes = Rijndael.Create();
           using (MemoryStream mStream = new MemoryStream())
           {
               using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateEncryptor(bKey, bIV), CryptoStreamMode.Write))
               {
                   cStream.Write(byteArray, 0, byteArray.Length);
                   cStream.FlushFinalBlock();
                   encrypt = Convert.ToBase64String(mStream.ToArray());
               }
           }
           aes.Clear();
           return encrypt;
       }
       public static string AESDecryptASCII(string encryptStr)
       {
           encryptStr = Decode(encryptStr);
           byte[] bKey = Encoding.UTF8.GetBytes(GetKey());
           byte[] bIV = Encoding.UTF8.GetBytes(GetIV());
           byte[] byteArray = Convert.FromBase64String(encryptStr);

           string decrypt = null;
           Rijndael aes = Rijndael.Create();
           using (MemoryStream mStream = new MemoryStream())
           {
               using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateDecryptor(bKey, bIV), CryptoStreamMode.Write))
               {
                   cStream.Write(byteArray, 0, byteArray.Length);
                   cStream.FlushFinalBlock();
                   decrypt = Encoding.UTF8.GetString(mStream.ToArray());
               }
           }
           aes.Clear();
           return decrypt;
       }
       public static string AESDecrypt(string encryptStr)
       {
           byte[] bKey = Encoding.UTF8.GetBytes(GetKey());
           byte[] bIV = Encoding.UTF8.GetBytes(GetIV());
           byte[] byteArray = Convert.FromBase64String(encryptStr);

           string decrypt = null;
           Rijndael aes = Rijndael.Create();
           using (MemoryStream mStream = new MemoryStream())
           {
               using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateDecryptor(bKey, bIV), CryptoStreamMode.Write))
               {
                   cStream.Write(byteArray, 0, byteArray.Length);
                   cStream.FlushFinalBlock();
                   decrypt = Encoding.UTF8.GetString(mStream.ToArray());
               }
           }
           aes.Clear();
           return decrypt;
       }
       public static string Encode(string strEncode)
       {
           string strReturn = "";//  存储转换后的编码
           foreach (short shortx in strEncode.ToCharArray())
           {
               strReturn += shortx.ToString("X");
           }
           return strReturn;
       }

       public static string Decode(string strDecode)
       {
           string sResult = "";
           for (int i = 0; i < strDecode.Length / 2; i++)
           {
               sResult += (char)short.Parse(strDecode.Substring(i * 2, 2), global::System.Globalization.NumberStyles.HexNumber);
           }
           return sResult;
       }
       private static string GetKey()
       {
           return @")O[NB]6,YF}+efcaj{+oESb9d8>Z'e9M";
       }

       /// <summary>
       /// 获取向量
       /// </summary>
       private static string GetIV()
       {
           return @"L+~f4,Ir)b$=pkf";
       }
    }
}