AES加密，解密方法

//解密，fileIn:解密的文件路径，fileOut:解密后的文件存放路径,strKey:秘钥
public static void Decrypt(string fileIn, string fileOut, string strKey)
{
var fsIn = new FileStream(fileIn, FileMode.Open, FileAccess.Read);
var fsOut = new FileStream(fileOut, FileMode.OpenOrCreate, FileAccess.Write);
var rDel = new RijndaelManaged();
var key = Encoding.UTF8.GetBytes(strKey);
rDel.Key = key;
rDel.Mode = CipherMode.ECB;
rDel.Padding = PaddingMode.PKCS7;
var cs = new CryptoStream(fsOut, rDel.CreateDecryptor(), CryptoStreamMode.Write);
var bufferLen = 4096;
var buffer = new byte[bufferLen];
int bytesRead;
do
{
bytesRead = fsIn.Read(buffer, 0, bufferLen);
cs.Write(buffer, 0, bytesRead);
} while (bytesRead != 0);
cs.Close();
fsIn.Close();
fsIn.Dispose();
fsOut.Dispose();
}