公用方法

//文件转换为字节  
public static byte[] File2Bytes(string path)
        {
            if (!System.IO.File.Exists(path))
            {
                return new byte[0];
            }

            FileInfo fi = new FileInfo(path);
            byte[] buff = new byte[fi.Length];

            FileStream fs = fi.OpenRead();
            fs.Read(buff, 0, Convert.ToInt32(fs.Length));
            fs.Close();

            return buff;
        }

//生成压缩文件
public static void CompressedFiles(string topDirectoryName, string zipedFileName, int compresssionLevel, string password, string comment)
        {
            using (ZipOutputStream zos = new ZipOutputStream(System.IO.File.Open(zipedFileName, FileMode.OpenOrCreate)))
            {
                if (compresssionLevel != 0)
                {
                    zos.SetLevel(compresssionLevel);//设置压缩级别  
                }

                if (!string.IsNullOrEmpty(password))
                {
                    zos.Password = password;//设置zip包加密密码  
                }

                if (!string.IsNullOrEmpty(comment))
                {
                    zos.SetComment(comment);//设置zip包的注释  
                }

                //循环设置目录下所有的*.png文件（支持子目录搜索）  
                foreach (string file in Directory.GetFiles(topDirectoryName, "*.txt", SearchOption.AllDirectories))
                {
                    if (System.IO.File.Exists(file))
                    {
                        FileInfo item = new FileInfo(file);
                        FileStream fs = System.IO.File.OpenRead(item.FullName);
                        byte[] buffer = new byte[fs.Length];
                        fs.Read(buffer, 0, buffer.Length);

                        ZipEntry entry = new ZipEntry(item.Name);
                        zos.PutNextEntry(entry);       
                        zos.Write(buffer, 0, buffer.Length);
                    }
                }
            }
        }