c# AES128 加解密算法

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.IO;
using System.Security.Cryptography;

namespace AESEncoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var encoder = new AESEncoder("@111>111@222>222@333>333");
            var a = encoder.EncryptString("abc");
            var b = encoder.DecryptString(a);
        }

        /// <summary>
        /// DESEncrypt加密解密算法。
        /// </summary>
        public class AESEncoder
        {

            public AESEncoder(string key)
            {
                this.Key = key;
            }

            /// <summary>
            /// 对称加密解密的密钥
            /// </summary>
            public string Key { get; private set; }

            /// <summary>
            /// DES加密
            /// </summary>
            /// <param name="encryptString"></param>
            /// <returns></returns>
            public string EncryptString(string data)
            {
                byte[] keyArray = UTF8Encoding.UTF8.GetBytes(this.Key);
                byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(data);
                RijndaelManaged rDel = new RijndaelManaged();
                rDel.Key = keyArray;
                rDel.Mode = CipherMode.ECB;
                rDel.Padding = PaddingMode.PKCS7;
                ICryptoTransform cTransform = rDel.CreateEncryptor();
                byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, , toEncryptArray.Length);
                return Convert.ToBase64String(resultArray, , resultArray.Length);
            }

            /// <summary>
            /// DES解密
            /// </summary>
            /// <param name="decryptString"></param>
            /// <returns></returns>
            public string DecryptString(string data)
            {
                byte[] keyArray = UTF8Encoding.UTF8.GetBytes(this.Key);
                byte[] toEncryptArray = Convert.FromBase64String(data);
                RijndaelManaged rDel = new RijndaelManaged();
                rDel.Key = keyArray;
                rDel.Mode = CipherMode.ECB;
                rDel.Padding = PaddingMode.PKCS7;
                ICryptoTransform cTransform = rDel.CreateDecryptor();
                byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, , toEncryptArray.Length);
                return UTF8Encoding.UTF8.GetString(resultArray);
            }

            public bool EncryptFile(string filepath)
            {
                try
                {
                    var bytes = File.ReadAllBytes(filepath);
                    File.WriteAllBytes(filepath, Encoding.UTF8.GetBytes(this.EncryptString(Convert.ToBase64String(bytes))));
                    return true;
                }
                catch (Exception ex)
                {
                    Debug.Print(ex.ToString());
                    return false;
                }
            }

            public bool DecryptFile(string filepath)
            {
                try
                {
                    var bytes = File.ReadAllBytes(filepath);
                    File.WriteAllBytes(filepath, Convert.FromBase64String(this.DecryptString(Encoding.UTF8.GetString(bytes))));
                    return true;
                }
                catch (Exception ex)
                {
                    Debug.Print(ex.ToString());
                    return false;
                }
            }
        }
    }
}

/// <summary>
        /// AES256加密解密算法。
        /// </summary>
        public class AESEncoder
        {

            public AESEncoder(string key)
            {
                this.Key = key;
            }

            /// <summary>
            /// 对称加密解密的密钥
            /// </summary>
            public string Key { get; private set; }

            /// <summary>
            /// DES加密
            /// </summary>
            /// <param name="encryptString"></param>
            /// <returns></returns>
            public byte[] EncryptBytes(byte[] data)
            {
                byte[] keyArray = UTF8Encoding.UTF8.GetBytes(this.Key);
                RijndaelManaged rDel = new RijndaelManaged();
                rDel.Key = keyArray;
                rDel.Mode = CipherMode.ECB;
                rDel.Padding = PaddingMode.PKCS7;
                ICryptoTransform cTransform = rDel.CreateEncryptor();
                byte[] resultArray = cTransform.TransformFinalBlock(data, , data.Length);
                return resultArray;
            }

            /// <summary>
            /// DES解密
            /// </summary>
            /// <param name="decryptString"></param>
            /// <returns></returns>
            public byte[] DecryptBytes(byte[] data)
            {
                byte[] keyArray = UTF8Encoding.UTF8.GetBytes(this.Key);
                RijndaelManaged rDel = new RijndaelManaged();
                rDel.Key = keyArray;
                rDel.Mode = CipherMode.ECB;
                rDel.Padding = PaddingMode.PKCS7;
                ICryptoTransform cTransform = rDel.CreateDecryptor();
                byte[] resultArray = cTransform.TransformFinalBlock(data, , data.Length);
                return resultArray;
            }
        }