/// <summary>
        /// zip压缩
        /// </summary>
        /// <param name="path">源文件夹路径</param>
        /// <param name="topath">目标文件路径</param>
        /// <returns>-1=文件不存在,0=未知错误,1=成功</returns>
        public static int ZipCompress(string path, string topath)
        {
            //文件夹不存在
            if (!Directory.Exists(path))
            {
                return -1;
            }

            try
            {
                string[] filenames = Directory.GetFiles(path);
                using (ZipOutputStream s = new ZipOutputStream(File.Create(topath)))
                {
                    s.SetLevel(9); // 0 - store only to 9 - means best compression
                    byte[] buffer = new byte[4096];
                    foreach (string file in filenames)
                    {
                        ZipEntry entry = new ZipEntry(Path.GetFileName(file));
                        entry.DateTime = DateTime.Now;
                        s.PutNextEntry(entry);
                        using (FileStream fs = File.OpenRead(file))
                        {
                            int sourceBytes;
                            do
                            {
                                sourceBytes = fs.Read(buffer, 0, buffer.Length);
                                s.Write(buffer, 0, sourceBytes);
                            } while (sourceBytes > 0);
                        }
                    }
                    s.Finish();
                    s.Close();
                }
                return 1;
            }
            catch (Exception ex)
            {
                return 0;
            }
        }