c#|c# 用ICSharpCode组件压缩文件

一、单文件压缩 场景,文件可能比较大,需要压缩传输,比如上传和下载

/// /// 单文件压缩/// /// 源文件/// zip压缩文件/// 缓冲区大小/// 压缩级别public static void ZipFile(string sourceFile, string zipedFile, int blockSize = 1024, int compressionLevel = 6){if (!File.Exists(sourceFile)){throw new System.IO.FileNotFoundException("The specified file " + sourceFile + " could not be found."); }var fileName = System.IO.Path.GetFileNameWithoutExtension(sourceFile); FileStream streamToZip = new FileStream(sourceFile, FileMode.Open, FileAccess.Read); FileStream zipFile = File.Create(zipedFile); ZipOutputStream zipStream = new ZipOutputStream(zipFile); ZipEntry zipEntry = new ZipEntry(fileName); zipStream.PutNextEntry(zipEntry); //存储、最快、较快、标准、较好、最好0-9zipStream.SetLevel(compressionLevel); byte[] buffer = new byte[blockSize]; int size = streamToZip.Read(buffer, 0, buffer.Length); zipStream.Write(buffer, 0, size); try{while (size < streamToZip.Length){int sizeRead = streamToZip.Read(buffer, 0, buffer.Length); zipStream.Write(buffer, 0, sizeRead); size += sizeRead; }}catch (Exception ex){throw ex; }zipStream.Finish(); zipStream.Close(); streamToZip.Close(); }

说明:26行,blocksize为缓存区大小,不能设置太大,如果太大也会报异常。26-38行,把文件通过FileStream流,读取到缓冲区中,再写入到ZipOutputStream流。你可以想象,两个管道,一个读,另一个写,中间是缓冲区,它们的工作方式是同步的方式。想一下,能不能以异步的方式工作,读的管道只管读,写的管道只管写?如果是这样一个场景,读的特别快,写的比较慢,比如,不是本地写,而是要经过网络传输,就可以考虑异步的方式。怎么做,读者可以自行改造。关键一点,流是有顺序的,所以要保证顺序的正确性即可。
二、多文件压缩 这种场景也是比较多见,和单文件压缩类似,无非就是多循环几次。
/// /// 多文件压缩/// /// zip压缩文件/// 源文件集合/// 压缩加密public void ZipFiles(string zipfile, string[] filenames, string password = ""){ZipOutputStream s = new ZipOutputStream(System.IO.File.Create(zipfile)); s.SetLevel(6); if (password != "")s.Password = Md5Help.Encrypt(password); foreach (string file in filenames){//打开压缩文件FileStream fs = File.OpenRead(file); byte[] buffer = new byte[fs.Length]; fs.Read(buffer, 0, buffer.Length); var name = Path.GetFileName(file); ZipEntry entry = new ZipEntry(name); entry.DateTime = DateTime.Now; entry.Size = fs.Length; fs.Close(); s.PutNextEntry(entry); s.Write(buffer, 0, buffer.Length); }s.Finish(); s.Close(); }

说明:21行,缓冲区大小直接为文件大小,所以一次读完,没有循环读写。这种情况下,单个文件不能太大,比如超过1G。14行,可以为压缩包设置密码,MD5的生成方法如下:
public class Md5Help{/// ///32位 MD5加密/// /// 加密字符/// public static string Encrypt(string str){MD5 md5 = new MD5CryptoServiceProvider(); byte[] encryptdata = https://www.it610.com/article/md5.ComputeHash(Encoding.UTF8.GetBytes(str)); return Convert.ToBase64String(encryptdata); }}

三、多文件异步压缩 上面同步的压缩的前提是,假设文件不大,而且文件数不多,但是现实是,不光文件大,而且文件数比较多。这种情况,就要考虑异步方法了。否则会阻塞主线程,就是我们平常说的卡死。
/// /// 异步压缩文件为zip压缩包/// /// 压缩包存储路径/// 文件集合public static async void ZipFilesAsync(string zipfile, string[] filenames){await Task.Run(() =>{ZipOutputStream s = null; try{s = new ZipOutputStream(System.IO.File.Create(zipfile)); s.SetLevel(6); // 0 - store only to 9 - means best compression foreach (string file in filenames){//打开压缩文件 FileStream fs = System.IO.File.OpenRead(file); var name = Path.GetFileName(file); ZipEntry entry = new ZipEntry(name); entry.DateTime = DateTime.Now; entry.Size = fs.Length; s.PutNextEntry(entry); //如果文件大于1Glong blockSize = 51200; var size = (int)fs.Length; var oneG = 1024 * 1024 * 1024; if (size > oneG){blockSize = oneG; }byte[] buffer = new byte[blockSize]; size = fs.Read(buffer, 0, buffer.Length); s.Write(buffer, 0, size); while (size < fs.Length){int sizeRead = fs.Read(buffer, 0, buffer.Length); s.Write(buffer, 0, sizeRead); size += sizeRead; }s.Flush(); fs.Close(); }}catch (Exception ex){Console.WriteLine("异步压缩文件出错:" + ex.Message); }finally{s?.Finish(); s?.Close(); }}); }

四、压缩文件夹 实际的应用当中,是文件和文件夹一起压缩,所以这种情况,就干脆把要压缩的东西全部放到一个文件夹,然后进行压缩。
主方法如下:
/// /// 异步压缩文件夹为zip压缩包/// /// 压缩包存储路径/// 压缩包存储路径/// 文件集合public static async void ZipFolderAsync(string zipfile, string sourceFolder, string[] filenames){await Task.Run(() =>{ZipOutputStream s = null; try{s = new ZipOutputStream(System.IO.File.Create(zipfile)); s.SetLevel(6); // 0 - store only to 9 - means best compression CompressFolder(sourceFolder, s, sourceFolder); }catch (Exception ex){Console.WriteLine("异步压缩文件出错:" + ex.Message); }finally{s?.Finish(); s?.Close(); }}); }

压缩的核心方法:
/// /// 压缩文件夹/// /// 源目录/// ZipOutputStream对象/// 和source相同public static void CompressFolder(string source, ZipOutputStream s, string parentPath){string[] filenames = Directory.GetFileSystemEntries(source); foreach (string file in filenames){if (Directory.Exists(file)){CompressFolder(file, s, parentPath); //递归压缩子文件夹}else{using (FileStream fs = System.IO.File.OpenRead(file)){var writeFilePath = file.Replace(parentPath, ""); ZipEntry entry = new ZipEntry(writeFilePath); entry.DateTime = DateTime.Now; entry.Size = fs.Length; s.PutNextEntry(entry); //如果文件大于1Glong blockSize = 51200; var size = (int)fs.Length; var oneG = 1024 * 1024 * 1024; if (size > oneG){blockSize = oneG; }byte[] buffer = new byte[blockSize]; size = fs.Read(buffer, 0, buffer.Length); s.Write(buffer, 0, size); while (size < fs.Length){int sizeRead = fs.Read(buffer, 0, buffer.Length); s.Write(buffer, 0, sizeRead); size += sizeRead; }s.Flush(); //清除流的缓冲区,使得所有缓冲数据都写入到文件中fs.Close(); }}}}

唯一需要注意的地方,可能解压出来的目录结构和压缩前的文件目录不同,这时候检查parentPath参数,它在ZipEntry实体new的时候用,替换绝对路径为当前的相对路径,也就是相对压缩文件夹的路径。
上面的方法比较复杂,还有一种相对简单的方式,直接调用api:
public static string ZipFolder(string sourceFolder, string zipFile){string result = ""; try{//创建压缩包if (!Directory.Exists(sourceFolder)) return result = "压缩文件夹不存在"; DirectoryInfo d = new DirectoryInfo(sourceFolder); var files = d.GetFiles(); if (files.Length == 0){//找子目录var ds = d.GetDirectories(); if (ds.Length > 0){files = ds[0].GetFiles(); }}if (files.Length == 0) return result = "待压缩文件为空"; System.IO.Compression.ZipFile.CreateFromDirectory(sourceFolder, zipFile); }catch (Exception ex){result += "压缩出错:" + ex.Message; }return result; }

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