DES加密后解密老是多出几个乱码，救急！

Question

        /// <summary>
        /// 加密文件
        /// </summary>
        /// <param name="sInputFilename"></param>
        /// <param name="sOutputFilename"></param>
        /// <param name="sKey"></param>
        public static void EncryptFile(string sInputFilename, string sOutputFilename)
        {
          
            DESCryptoServiceProvider DES = new DESCryptoServiceProvider();
            DES.Key = System.Text.Encoding.UTF8.GetBytes(sKey);
            DES.IV = System.Text.Encoding.UTF8.GetBytes(sKey);            byte[] btFile = File.ReadAllBytes(sInputFilename);            using (FileStream fsread = new FileStream(sOutputFilename, FileMode.Open, FileAccess.Write) )
            {
                ICryptoTransform desdecrypt = DES.CreateEncryptor();
                CryptoStream cryptostreamDecr = new CryptoStream(fsread, desdecrypt, CryptoStreamMode.Write);
                cryptostreamDecr.Write(btFile, 0, btFile.Length);
                cryptostreamDecr.FlushFinalBlock();
                cryptostreamDecr.Close();
                fsread.Close();
            }
        }        /// <summary>
        /// 解密文件
        /// </summary>
        /// <param name="sInputFilename"></param>
        /// <param name="sOutputFilename"></param>
        /// <param name="sKey"></param>
        public static void DecryptFile(string sInputFilename, string sOutputFilename)
        {
            DESCryptoServiceProvider DES = new DESCryptoServiceProvider();
            DES.Key = System.Text.Encoding.UTF8.GetBytes(sKey);
            DES.IV = System.Text.Encoding.UTF8.GetBytes(sKey);            byte[] btFile = File.ReadAllBytes(sInputFilename);            using (FileStream fsread = new FileStream(sOutputFilename, FileMode.Open, FileAccess.Write))
            {
                ICryptoTransform desdecrypt = DES.CreateDecryptor();
                CryptoStream cryptostreamDecr = new CryptoStream(fsread, desdecrypt, CryptoStreamMode.Write);
                cryptostreamDecr.Write(btFile, 0, btFile.Length);
                cryptostreamDecr.FlushFinalBlock();
                cryptostreamDecr.Close();
                fsread.Close();
            }
        }des

Answer 1

这个问题我也遇到过，因为解密后的byte[]的末尾会有好几个0,把那几个0去掉就行

Answer 2

new FileStream(sOutputFilename, FileMode.Open, FileAccess.Write) 
改成：
FileMode.Create长度100文件用FileMode.Open打开后写入90字节，前90字节被覆盖，但文件长度将还是100。