我有一个内存流，其中包含byte[]格式的 zip 文件。有什么方法可以解压缩这个内存流，而不需要将文件写入磁盘？
一般来说，我ICSharpCode.SharpZipLib.Zip.FastZip用来解压缩文件，但是有没有办法解压缩内存流，可能是通过将文件存储为另一种文件MemoryStream或byte[]根据 zip 中存在的文件/文件夹的格式存储文件？
在这种情况下，我有什么办法可以使用 Memorymapped 文件功能？
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4 回答
123
这是基于您的描述的代码示例。
在您的项目中，右键单击 References 文件夹并添加对System.IO.Compression的引用
using System.IO.Compression;
Stream data = new MemoryStream(); // The original data
Stream unzippedEntryStream; // Unzipped data from a file in the archive
ZipArchive archive = new ZipArchive(data);
foreach (ZipArchiveEntry entry in archive.Entries)
{
if(entry.FullName.EndsWith(".txt", StringComparison.OrdinalIgnoreCase))
{
unzippedEntryStream = entry.Open(); // .Open will return a stream
// Process entry data here
}
}
希望这可以帮助。
于 2014-02-13T22:38:13.077 回答
21
我们使用DotNetZip，我可以将 zip 文件的内容从 a 解压缩Stream到内存中。下面是从流 ( ) 中提取特定命名文件LocalCatalogZip并返回流以读取该文件的示例代码，但在此基础上进行扩展很容易。
private static MemoryStream UnZipCatalog()
{
MemoryStream data = new MemoryStream();
using (ZipFile zip = ZipFile.Read(LocalCatalogZip))
{
zip["ListingExport.txt"].Extract(data);
}
data.Seek(0, SeekOrigin.Begin);
return data;
}
它不是您现在使用的库，但如果您可以更改，您可以获得该功能。
这是一个变体，它将Dictionary<string,MemoryStream>为 zip 文件的每个文件的内容返回 a。
private static Dictionary<string,MemoryStream> UnZipToMemory()
{
var result = new Dictionary<string,MemoryStream>();
using (ZipFile zip = ZipFile.Read(LocalCatalogZip))
{
foreach (ZipEntry e in zip)
{
MemoryStream data = new MemoryStream();
e.Extract(data);
result.Add(e.FileName, data);
}
}
return result;
}
于 2012-10-03T20:23:44.363 回答
16
我刚刚遇到了类似的问题，我发现我认为似乎相当优雅的答案是使用#ZipLib（可使用nuget）并执行以下操作：
private byte[] GetUncompressedPayload(byte[] data)
{
using (var outputStream = new MemoryStream())
using (var inputStream = new MemoryStream(data))
{
using (var zipInputStream = new ZipInputStream(inputStream))
{
zipInputStream.GetNextEntry();
zipInputStream.CopyTo(outputStream);
}
return outputStream.ToArray();
}
}
这似乎奏效了。希望这可以帮助。
于 2013-11-29T12:02:23.740 回答
8
是的，从使用FastZipTo更改new ZipFile(stream)，但这仅在您的流可以搜索时才有效。（只需使用您的 MemoryStreamnew ZipFile(fs);而不是像示例中那样读取文件流。）
C#
using ICSharpCode.SharpZipLib.Core;
using ICSharpCode.SharpZipLib.Zip;
public void ExtractZipFile(string archiveFilenameIn, string password, string outFolder) {
ZipFile zf = null;
try {
FileStream fs = File.OpenRead(archiveFilenameIn);
zf = new ZipFile(fs);
if (!String.IsNullOrEmpty(password)) {
zf.Password = password; // AES encrypted entries are handled automatically
}
foreach (ZipEntry zipEntry in zf) {
if (!zipEntry.IsFile) {
continue; // Ignore directories
}
String entryFileName = zipEntry.Name;
// to remove the folder from the entry:- entryFileName = Path.GetFileName(entryFileName);
// Optionally match entrynames against a selection list here to skip as desired.
// The unpacked length is available in the zipEntry.Size property.
byte[] buffer = new byte[4096]; // 4K is optimum
Stream zipStream = zf.GetInputStream(zipEntry);
// Manipulate the output filename here as desired.
String fullZipToPath = Path.Combine(outFolder, entryFileName);
string directoryName = Path.GetDirectoryName(fullZipToPath);
if (directoryName.Length > 0)
Directory.CreateDirectory(directoryName);
// Unzip file in buffered chunks. This is just as fast as unpacking to a buffer the full size
// of the file, but does not waste memory.
// The "using" will close the stream even if an exception occurs.
using (FileStream streamWriter = File.Create(fullZipToPath)) {
StreamUtils.Copy(zipStream, streamWriter, buffer);
}
}
} finally {
if (zf != null) {
zf.IsStreamOwner = true; // Makes close also shut the underlying stream
zf.Close(); // Ensure we release resources
}
}
}
如果您使用的是不可搜索的流，请使用 ZipInputStream。
// Calling example:
WebClient webClient = new WebClient();
Stream data = webClient.OpenRead("http://www.example.com/test.zip");
// This stream cannot be opened with the ZipFile class because CanSeek is false.
UnzipFromStream(data, @"c:\temp");
public void UnzipFromStream(Stream zipStream, string outFolder) {
ZipInputStream zipInputStream = new ZipInputStream(zipStream);
ZipEntry zipEntry = zipInputStream.GetNextEntry();
while (zipEntry != null) {
String entryFileName = zipEntry.Name;
// to remove the folder from the entry:- entryFileName = Path.GetFileName(entryFileName);
// Optionally match entrynames against a selection list here to skip as desired.
// The unpacked length is available in the zipEntry.Size property.
byte[] buffer = new byte[4096]; // 4K is optimum
// Manipulate the output filename here as desired.
String fullZipToPath = Path.Combine(outFolder, entryFileName);
string directoryName = Path.GetDirectoryName(fullZipToPath);
if (directoryName.Length > 0)
Directory.CreateDirectory(directoryName);
// Unzip file in buffered chunks. This is just as fast as unpacking to a buffer the full size
// of the file, but does not waste memory.
// The "using" will close the stream even if an exception occurs.
using (FileStream streamWriter = File.Create(fullZipToPath)) {
StreamUtils.Copy(zipInputStream, streamWriter, buffer);
}
zipEntry = zipInputStream.GetNextEntry();
}
}
于 2012-10-03T21:35:25.890 回答