使用SharpZipLib解压缩特定文件？

Question

我正在尝试使用SharpZipLib从zip存档中提取指定的文件.我见过的所有例子总是希望你能解压缩整个拉链,并按照以下方式做一些事情:

       FileStream fileStreamIn = new FileStream (sourcePath, FileMode.Open, FileAccess.Read);

        ZipInputStream zipInStream = new ZipInputStream(fileStreamIn);
        ZipEntry entry;

        while (entry = zipInStream.GetNextEntry() != null)
        {
            // Unzip file
        }

我想做的是:

ZipEntry entry = zipInStream.SeekToFile("FileName");

因为我的需求涉及使用zip作为包,只根据需要将文件抓取到内存中.

有人熟悉SharpZipLib吗？有没有人知道我是否可以手动完成整个拉链？

Answer 1

ZipFile.GetEntry应该做的伎俩:

using (var fs = new FileStream(sourcePath, FileMode.Open, FileAccess.Read))
using (var zf = new ZipFile(fs)) {
   var ze = zf.GetEntry(fileName);
   if (ze == null) {
      throw new ArgumentException(fileName, "not found in Zip");
   }

   using (var s = zf.GetInputStream(ze)) {
      // do something with ZipInputStream
   }
}

Answer 2

FastZip.ExtractZip (string zipFileName, string targetDirectory, string fileFilter)

可以根据文件过滤器提取一个或多个文件(即常规expressoin字符串)

这是关于文件过滤器的文档:

// A filter is a sequence of independant <see cref="Regex">regular expressions</see> separated by semi-colons ';'
// Each expression can be prefixed by a plus '+' sign or a minus '-' sign to denote the expression
// is intended to include or exclude names.  If neither a plus or minus sign is found include is the default
// A given name is tested for inclusion before checking exclusions.  Only names matching an include spec
// and not matching an exclude spec are deemed to match the filter.
// An empty filter matches any name.
// </summary>
// <example>The following expression includes all name ending in '.dat' with the exception of 'dummy.dat'
// "+\.dat$;-^dummy\.dat$"

因此,对于名为myfile.dat的文件,您可以使用"+.*myfile\.dat $"作为文件过滤器.

Answer 3

DotNetZip在ZipFile类上有一个字符串索引器,使这很容易.

 using (ZipFile zip = ZipFile.Read(sourcePath)
 {
   zip["NameOfFileToUnzip.txt"].Extract();
 }

您不需要调整输入流和输出流等,只需提取文件即可.另一方面,如果你想要流,你可以得到它:

 using (ZipFile zip = ZipFile.Read(sourcePath)
 {
   Stream s = zip["NameOfFileToUnzip.txt"].OpenReader();
   // fiddle with stream here
 }

您也可以进行通配符提取.

 using (ZipFile zip = ZipFile.Read(sourcePath)
 {
     // extract all XML files in the archive
     zip.ExtractSelectedEntries("*.xml");
 }

有重载指定覆盖/不覆盖,不同的目标目录等.您还可以根据文件名以外的条件进行提取.例如,提取比2009年1月15日更新的所有文件:

     // extract all files modified after 15 Jan 2009
     zip.ExtractSelectedEntries("mtime > 2009-01-15");

你可以结合标准:

     // extract all files that are modified after 15 Jan 2009) AND  larger than 1mb
     zip.ExtractSelectedEntries("mtime > 2009-01-15 and size > 1mb");

     // extract all XML files that are modified after 15 Jan 2009) AND  larger than 1mb
     zip.ExtractSelectedEntries("name = *.xml and mtime > 2009-01-15 and size > 1mb");

您不必解压缩所选的文件.您可以选择它们,然后决定是否提取.

    using (ZipFile zip1 = ZipFile.Read(ZipFileName))
    {
        var PhotoShopFiles = zip1.SelectEntries("*.psd");
        // the selection is just an ICollection<ZipEntry>
        foreach (ZipEntry e in PhotoShopFiles)
        {
            // examine metadata here, make decision on extraction
            e.Extract();
        }
    }