文件壓縮和解壓 FileStream GZipStream

  using (FileStream reader=new FileStream (@"c:\1.txt",FileMode.Open,FileAccess.Read))
            {
                using (FileStream writer=new FileStream (@"c:\4.zp",FileMode.OpenOrCreate,FileAccess.Write))
                {
                    //壓縮寫的流
                    using (GZipStream zip=new GZipStream (writer,CompressionMode.Compress))
                    {
                        byte[] buffer = new byte[12];
                        int r = 0;
                        while ((r=reader.Read(buffer,0,buffer.Length))>0)
                        {
                            //壓縮寫入
                            zip.Write(buffer,0,r);
                            
                        }
                    }
                }
            }
            Console.WriteLine("/壓縮完成");

            using (FileStream reader = new FileStream(@"c:\4.zp", FileMode.OpenOrCreate, FileAccess.Read))
            {
                using (FileStream writer = new FileStream(@"c:\5.txt", FileMode.OpenOrCreate, FileAccess.Write))
                {
                    byte[] buffer = new byte[13];
                    //解壓讀的流 因讀的是壓縮文件，reader讀出的是壓縮後的流
                    using (GZipStream zip = new GZipStream(reader, CompressionMode.Decompress))
                    {
                        int r=0;
                        
                        while ((r = zip.Read(buffer, 0, buffer.Length)) > 0)
                        {
                            //正常的流寫入
                            writer.Write(buffer, 0, r);
                        }
                    }

                }
            }

這種壓縮只能實現單個文件的壓縮和解壓，多個文件的暫時不能使用