public string Comprimir(string diretorio)
        {
            string[]     files        = Directory.GetFiles(diretorio);
            MemoryStream memoryStream = new MemoryStream();
            string       result;

            using (Ionic.Zip.ZipOutputStream zipOutputStream = new Ionic.Zip.ZipOutputStream(memoryStream))
            {
                byte[]   array  = new byte[4096];
                string[] array2 = files;
                for (int i = 0; i < array2.Length; i++)
                {
                    string             path     = array2[i];
                    Ionic.Zip.ZipEntry zipEntry = new Ionic.Zip.ZipEntry();
                    zipOutputStream.PutNextEntry(Path.GetFileName(path));
                    using (FileStream fileStream = File.OpenRead(path))
                    {
                        int num;
                        do
                        {
                            num = fileStream.Read(array, 0, array.Length);
                            zipOutputStream.Write(array, 0, num);
                        }while (num > 0);
                    }
                }
                zipOutputStream.Close();
                byte[] array3 = memoryStream.ToArray();
                result = Convert.ToBase64String(array3, 0, array3.Length);
            }
            return(result);
        }
        public string ComprimirArquivo(string arquivo)
        {
            MemoryStream memoryStream = new MemoryStream();
            string       result;

            using (Ionic.Zip.ZipOutputStream zipOutputStream = new Ionic.Zip.ZipOutputStream(memoryStream))
            {
                byte[]             array    = new byte[4096];
                Ionic.Zip.ZipEntry zipEntry = new Ionic.Zip.ZipEntry();
                zipOutputStream.PutNextEntry(Path.GetFileName(arquivo));
                using (FileStream fileStream = File.OpenRead(arquivo))
                {
                    int num;
                    do
                    {
                        num = fileStream.Read(array, 0, array.Length);
                        zipOutputStream.Write(array, 0, num);
                    }while (num > 0);
                }
                zipOutputStream.Close();
                byte[] array2 = memoryStream.ToArray();
                result = Convert.ToBase64String(array2, 0, array2.Length);
            }
            return(result);
        }
        public string Comprimir2Base64(object[] arquivos)
        {
            MemoryStream memoryStream = new MemoryStream();

            using (Ionic.Zip.ZipOutputStream zipOutputStream = new Ionic.Zip.ZipOutputStream(memoryStream))
            {
                byte[] array = new byte[4096];
                for (int i = 0; i < arquivos.Length; i++)
                {
                    ArquivoPdf         arquivoPdf    = (ArquivoPdf)arquivos[i];
                    MemoryStream       memoryStream2 = new MemoryStream(arquivoPdf.Dados);
                    Ionic.Zip.ZipEntry zipEntry      = new Ionic.Zip.ZipEntry();
                    zipOutputStream.PutNextEntry(arquivoPdf.Nome);
                    int num;
                    do
                    {
                        num = memoryStream2.Read(array, 0, array.Length);
                        zipOutputStream.Write(array, 0, num);
                    }while (num > 0);
                }
                zipOutputStream.Close();
            }
            byte[] array2 = memoryStream.ToArray();
            return(Convert.ToBase64String(array2, 0, array2.Length));
        }