// supprimer un fichier
        public void Delete(string args)
        {
            string fileToDelete = args;
            System.IO.File.Delete(fileToDelete);

        }

        // extraire un zip
        public void _ExtractFilesFromZip(string zipFilename, string destFolder, string password, bool overwrite)
        {
            if (!destFolder.EndsWith("\\")) destFolder = destFolder + '\\';

            ZipInputStream zipStream = new ZipInputStream(
                new FileStream(zipFilename, FileMode.Open));
            try
            {
                zipStream.Password = password;

                ZipEntry zipEntry;
                byte[] buff = new byte[65536];
                while ((zipEntry = zipStream.GetNextEntry()) != null)
                {
                    if (zipEntry.IsDirectory)
                    {
                        if (!Directory.Exists(destFolder + zipEntry.Name.TrimStart('/')))
                            Directory.CreateDirectory(destFolder + zipEntry.Name.TrimStart('/'));
                        while (zipStream.Read(buff, 0, buff.Length) > 0) { }
                    }
                    else
                    {
                        if (!File.Exists(destFolder + zipEntry.Name.TrimStart('/')) || overwrite)
                        {
                            string dirName = System.IO.Path.GetDirectoryName(destFolder + zipEntry.Name);
                            if (!Directory.Exists(dirName))
                            {
                                Directory.CreateDirectory(dirName);
                            }
                            SaveFile(zipStream, destFolder + zipEntry.Name, zipEntry.Size);
                        }
                    }
                }

            }
            finally
            {
                zipStream.Close();
                Delete(zipFilename);
            }

        }
        public void SaveFile(Stream stream, string fullName, long uncompressedSize)
        {
            if (!stream.CanRead || stream.Length <= 0) return;
            FileStream fs = null;
            try
            {
                byte[] buff = new byte[65536];
                fs = new FileStream(fullName, FileMode.Create);
                int res;
                if (uncompressedSize > 0)
                {
                    while ((res = stream.Read(buff, 0, buff.Length)) > 0)
                        fs.Write(buff, 0, res);
                }
            }
            finally
            {
                if (fs != null) fs.Close();
            }
        }