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asp.net实现zip压缩与解压缩

在.net可以通过多种方式实现zip的压缩和解压:
1、使用system.io.packaging;
2、使用第三方类库;
3、通过 system.io.compression 命名空间中新增的ziparchive、zipfile等类实现。

一、使用system.io.packaging压缩和解压

package为一个抽象类,可用于将对象组织到定义的物理格式的单个实体中,从而实现可移植性与高效访问。zip 文件是package的主物理格式。 其他package实现可以使用其他物理格式(如 xml 文档、数据库或 web 服务。与文件系统类似,在分层组织的文件夹和文件中引用 package 中包含的项。虽然 package 是抽象类,但 package.open 方法默认使用 zippackage 派生类。

system.io.packaging在windowsbase.dll程序集下,使用时需要添加对windowsbase的引用。

1、将整个文件夹压缩成zip
 

复制代码 代码示例:

/// <summary>
/// add a folder along with its subfolders to a package
/// </summary>
/// <param name="foldername">the folder to add</param>
/// <param name="compressedfilename">the package to create</param>
/// <param name="overrideexisting">override exsisitng files</param>
/// <returns></returns>
static bool packagefolder(string foldername, string compressedfilename, bool overrideexisting)
{
  if (foldername.endswith(@"\"))
 foldername = foldername.remove(foldername.length - 1);
  bool result = false;
  if (!directory.exists(foldername))
  {
 return result;
  }

  if (!overrideexisting && file.exists(compressedfilename))
  {
 return result;
  }
  try
  {
 using (package package = package.open(compressedfilename, filemode.create))
 {
var filelist = directory.enumeratefiles(foldername, "*", searchoption.alldirectories);
foreach (string filename in filelist)
{
  
    //the path in the package is all of the subfolders after foldername
    string pathinpackage;
    pathinpackage = path.getdirectoryname(filename).replace(foldername, string.empty) + "/" + path.getfilename(filename);

    uri parturidocument = packurihelper.createparturi(new uri(pathinpackage, urikind.relative));
    packagepart packagepartdocument = package.createpart(parturidocument,"", compressionoption.maximum);
    using (filestream filestream = new filestream(filename, filemode.open, fileaccess.read))
    {
   filestream.copyto(packagepartdocument.getstream());
    }
}
 }
 result = true;
  }
  catch (exception e)
  {
 throw new exception("error zipping folder " + foldername, e);
  }
 
  return result;
   }
 

2、将单个文件添加到zip文件中
 

复制代码 代码示例:

/// <summary>
/// compress a file into a zip archive as the container store
/// </summary>
/// <param name="filename">the file to compress</param>
/// <param name="compressedfilename">the archive file</param>
/// <param name="overrideexisting">override existing file</param>
/// <returns></returns>
static bool packagefile(string filename, string compressedfilename, bool overrideexisting)
{
  bool result = false;

  if (!file.exists(filename))
  {
 return result;
  }

  if (!overrideexisting && file.exists(compressedfilename))
  {
 return result;
  }

try
{
 uri parturidocument = packurihelper.createparturi(new uri(path.getfilename(filename), urikind.relative));

using (package package = package.open(compressedfilename, filemode.openorcreate))
{
if (package.partexists(parturidocument))
{
    package.deletepart(parturidocument);
}

packagepart packagepartdocument = package.createpart(parturidocument, "", compressionoption.maximum);
using (filestream filestream = new filestream(filename, filemode.open, fileaccess.read))
{
    filestream.copyto(packagepartdocument.getstream());
}
 }
 result = true;
  }
  catch (exception e)
  {
 throw new exception("error zipping file " + filename, e);
  }
 
  return result;
   }
 

3、zip文件解压
 

复制代码 代码示例:

/// <summary>
/// extract a container zip. note: container must be created as open packaging conventions (opc) specification
/// </summary>
/// <param name="foldername">the folder to extract the package to</param>
/// <param name="compressedfilename">the package file</param>
/// <param name="overrideexisting">override existing files</param>
/// <returns></returns>
static bool uncompressfile(string foldername, string compressedfilename, bool overrideexisting)
{
  bool result = false;
  try
  {
 if (!file.exists(compressedfilename))
 {
return result;
 }

 directoryinfo directoryinfo = new directoryinfo(foldername);
 if (!directoryinfo.exists)
directoryinfo.create();

 using (package package = package.open(compressedfilename, filemode.open, fileaccess.read))
 {
foreach (packagepart packagepart in package.getparts())
{
    extractpart(packagepart, foldername, overrideexisting);
}
 }

 result = true;
  }
  catch (exception e)
  {
 throw new exception("error unzipping file " + compressedfilename, e);
  }
 
  return result;
   }

   static void extractpart(packagepart packagepart, string targetdirectory, bool overrideexisting)
   {
  string stringpart = targetdirectory + httputility.urldecode(packagepart.uri.tostring()).replace('\\', '/');

  if (!directory.exists(path.getdirectoryname(stringpart)))
 directory.createdirectory(path.getdirectoryname(stringpart));

  if (!overrideexisting && file.exists(stringpart))
 return;
  using (filestream filestream = new filestream(stringpart, filemode.create))
  {
 packagepart.getstream().copyto(filestream);
  }
   }

使用package压缩文件会在zip文件自动生成[content_type].xml,用来描述zip文件解压支持的文件格式。
 

复制代码 代码示例:
<?xml version="1.0" encoding="utf-8" ?>
<types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
    <default extension="vsixmanifest" contenttype="text/xml" />
    <default extension="dll" contenttype="application/octet-stream" />
    <default extension="png" contenttype="application/octet-stream" />
    <default extension="txt" contenttype="text/plain" />
    <default extension="pkgdef" contenttype="text/plain" />
</types>

  同样,如果zip文件不包含[content_type].xml文件,或者[content_type].xml文件不包含所对应扩展名的描述(手动添加的[content_type].xml也是可以),将无法解压文件。

二、使用第三方类库 zip的压缩和解压使用比较的有sharpziplib和dotnetzip。

1、sharpziplib,也称为“#ziplib”,基于gpl开源,支持zip,gzip,tar和bzip2的压缩和解压缩。
支持.net 1.1,net 2.0(3.5、4.0).

1,zip压缩
 

复制代码 代码示例:
public static void zip(string srcfile, string dstfile, int buffersize)
{
    filestream filestreamin = new filestream
(srcfile, filemode.open, fileaccess.read);
    filestream filestreamout = new filestream
(dstfile, filemode.create, fileaccess.write);
    zipoutputstream zipoutstream = new zipoutputstream(filestreamout);
    byte[] buffer = new byte<buffersize />;
    zipentry entry = new zipentry(path.getfilename(srcfile));
    zipoutstream.putnextentry(entry);
    int size;
    do
    {
   size = filestreamin.read(buffer, 0, buffer.length);
   zipoutstream.write(buffer, 0, size);
    } while (size > 0);
    zipoutstream.close();
    filestreamout.close();
    filestreamin.close();

 

2)、解压zip
 

复制代码 代码示例:
public static void unzip(string srcfile, string dstfile, int buffersize)
{
    filestream filestreamin = new filestream
(srcfile, filemode.open, fileaccess.read);
    zipinputstream zipinstream = new zipinputstream(filestreamin);
    zipentry entry = zipinstream.getnextentry();
    filestream filestreamout = new filestream
(dstfile + @"\" + entry.name, filemode.create, fileaccess.write);
    int size;
    byte[] buffer = new byte<buffersize />;
    do
    {
   size = zipinstream.read(buffer, 0, buffer.length);
   filestreamout.write(buffer, 0, size);
    } while (size > 0);
    zipinstream.close();
    filestreamout.close();
    filestreamin.close();
}

2、dotnetlib,是基于”ws-pl”开源,使用比较简单
1)、压缩
 

复制代码 代码示例:
using (zipfile zip = new zipfile())
  {
    zip.addfile("readme.txt");
    zip.addfile("7440-n49th.png");
    zip.addfile("2008_annual_report.pdf");  
    zip.save("archive.zip");
  }
 

 2)、解压缩
 

复制代码 代码示例:
private void myextract()
  {
 string ziptounpack = "c1p3sml.zip";
 string unpackdirectory = "extracted files";
 using (zipfile zip1 = zipfile.read(ziptounpack))
 {
// here, we extract every entry, but we could extract conditionally
// based on entry name, size, date, checkbox status, etc. 
foreach (zipentry e in zip1)
{
  e.extract(unpackdirectory, extractexistingfileaction.overwritesilently);

  }
}

三、在.net 4.5使用ziparchive、zipfile等类压缩和解压
 

复制代码 代码示例:

static void main(string[] args)
{
  string zippath = @"d:\zzzyk.com.zip";
  string extractpath = @"d:\zzzyk.com";
  string newfile = @"d:\zzzyk.com\newfile.txt";

  using (ziparchive archive = zipfile.open(zippath, ziparchivemode.update))
  {
 archive.createentryfromfile(newfile, "newentry.txt");
 archive.extracttodirectory(extractpath);
  }
}

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