Creating a ZIP archive in memory using System.IO.Compression
I'm trying to create a ZIP archive with a simple demo text file using a MemoryStream as follows:
using (var memoryStream = new MemoryStream())
using (var archive = new ZipArchive(memoryStream , ZipArchiveMode.Create))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar!");
}
using (var fileStream = new FileStream(@"C:\Temp\test.zip", FileMode.Create))
{
stream.CopyTo(fileStream);
}
}
If I run this code, the archive file itself is created but foo.txt isn't.
However, if I replace the MemoryStream directly with the file stream, the archive is created correctly:
using (var fileStream = new FileStream(@"C:\Temp\test.zip", FileMode.Create))
using (var archive = new ZipArchive(fileStream, FileMode.Create))
{
// ...
}
Is it possible to use a MemoryStream to create the ZIP archive without the FileStream?
F.Y.I.: one needs at least .NET 4.5 for .ZipArchive. See Rick Strahl's .NET 4.5 is an in-place replacement for .NET 4.0 ~~ see also I didn't find “ZipFile” class in the “System.IO.Compression” namespace
If you want an example that uses binary data instead of strings, here's a good solution: stackoverflow.com/questions/48927574/…
M
Martin Prikryl
Thanks to ZipArchive creates invalid ZIP file, I got:
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar!");
}
}
using (var fileStream = new FileStream(@"C:\Temp\test.zip", FileMode.Create))
{
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}
}
That indicated we need to call Dispose on ZipArchive before we can use it, which as Amir suggests is likely because it writes final bytes like checksum to the archive that makes it complete. But in order not close the stream so we can re-use it after you need to pass true as the third parameter to ZipArchive.
M
Mitch Wheat
Just another version of zipping without writing any file.
string fileName = "export_" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".xlsx";
byte[] fileBytes = here is your file in bytes
byte[] compressedBytes;
string fileNameZip = "Export_" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".zip";
using (var outStream = new MemoryStream())
{
using (var archive = new ZipArchive(outStream, ZipArchiveMode.Create, true))
{
var fileInArchive = archive.CreateEntry(fileName, CompressionLevel.Optimal);
using (var entryStream = fileInArchive.Open())
using (var fileToCompressStream = new MemoryStream(fileBytes))
{
fileToCompressStream.CopyTo(entryStream);
}
}
compressedBytes = outStream.ToArray();
}
Simple and clean. Worked well for me using memorystreams Azure File Storage blobs
M
Mahesh
Set the position of the stream to the 0 before copying it to the zip stream.
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar!");
}
}
using (var fileStream = new FileStream(@"C:\Temp\test.zip", FileMode.Create))
{
memoryStream.Position=0;
memoryStream.WriteTo(fileStream);
}
}
Thanks for the straightforward solution. kudos!!
D
Debajit Mukhopadhyay
Working solution for MVC
public ActionResult Index()
{
string fileName = "test.pdf";
string fileName1 = "test.vsix";
string fileNameZip = "Export_" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".zip";
byte[] fileBytes = System.IO.File.ReadAllBytes(@"C:\test\test.pdf");
byte[] fileBytes1 = System.IO.File.ReadAllBytes(@"C:\test\test.vsix");
byte[] compressedBytes;
using (var outStream = new MemoryStream())
{
using (var archive = new ZipArchive(outStream, ZipArchiveMode.Create, true))
{
var fileInArchive = archive.CreateEntry(fileName, CompressionLevel.Optimal);
using (var entryStream = fileInArchive.Open())
using (var fileToCompressStream = new MemoryStream(fileBytes))
{
fileToCompressStream.CopyTo(entryStream);
}
var fileInArchive1 = archive.CreateEntry(fileName1, CompressionLevel.Optimal);
using (var entryStream = fileInArchive1.Open())
using (var fileToCompressStream = new MemoryStream(fileBytes1))
{
fileToCompressStream.CopyTo(entryStream);
}
}
compressedBytes = outStream.ToArray();
}
return File(compressedBytes, "application/zip", fileNameZip);
}
The
Controller.File method has an overload that accepts Stream. Use that to avoid creating yet another copy of a ZIP file in memory.
Jesus Christ, this is the first straight answer after an hour of googling. Thank you!
This solution works perfect! Thanks! You don't even need to move byte arrays (
byte[]). Just use a MemoryStream and don't forget to seek zero before you return the result back (.Seek(0, SeekOrigin.Begin);)
Can confirm this works for me in donet core 5.* w/ WebApi.
R
Rattle
You need to finish writing the memory stream then read the buffer back.
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar!");
}
}
using (var fileStream = new FileStream(@"C:\Temp\test.zip", FileMode.Create))
{
var bytes = memoryStream.GetBuffer();
fileStream.Write(bytes,0,bytes.Length );
}
}
F
FAREH
using System;
using System.IO;
using System.IO.Compression;
namespace ConsoleApplication
{
class Program`enter code here`
{
static void Main(string[] args)
{
using (FileStream zipToOpen = new FileStream(@"c:\users\exampleuser\release.zip", FileMode.Open))
{
using (ZipArchive archive = new ZipArchive(zipToOpen, ZipArchiveMode.Update))
{
ZipArchiveEntry readmeEntry = archive.CreateEntry("Readme.txt");
using (StreamWriter writer = new StreamWriter(readmeEntry.Open()))
{
writer.WriteLine("Information about this package.");
writer.WriteLine("========================");
}
}
}
}
}
}
M
Martin Prikryl
I'm late to the party, but there are scenarios where you can't access the ZipArchive's constructor to set the leaveOpen parameter and where you don't want the ZIP to be written to disk. In my case, the AsiceArchive class I'm using internally creates a ZipArchive but doesn't set leaveOpen to true.
I created a subclass of Stream that delegates all calls to an inner stream (a few clicks with ReSharper). This class is not disposable, so when the ZipArchive gets disposed, nothing happens to the inner stream.
public class NondisposingStreamWrapper : Stream
{
private readonly Stream _streamImplementation;
public NondisposingStreamWrapper(Stream inner) => _streamImplementation = inner;
public override void Flush() => _streamImplementation.Flush();
public override int Read(byte[] buffer, int offset, int count) => _streamImplementation.Read(buffer, offset, count);
public override long Seek(long offset, SeekOrigin origin) => _streamImplementation.Seek(offset, origin);
public override void SetLength(long value) => _streamImplementation.SetLength(value);
public override void Write(byte[] buffer, int offset, int count) => _streamImplementation.Write(buffer, offset, count);
public override bool CanRead => _streamImplementation.CanRead;
public override bool CanSeek => _streamImplementation.CanSeek;
public override bool CanWrite => _streamImplementation.CanWrite;
public override long Length => _streamImplementation.Length;
public override long Position
{
get => _streamImplementation.Position;
set => _streamImplementation.Position = value;
}
}
Use it like this:
using var memoryStream = new MemoryStream();
var output = new NondisposingStreamWrapper(memoryStream);
using (var archive = new ZipArchive(output, ZipArchiveMode.Create))
{
// add entries to archive
}
memoryStream.Flush();
memoryStream.Position = 0;
// write to file just for testing purposes
File.WriteAllBytes("out.zip", memoryStream.ToArray());
l
luisfbn
This is the way to convert a entity to XML File and then compress it:
private void downloadFile(EntityXML xml) {
string nameDownloadXml = "File_1.xml";
string nameDownloadZip = "File_1.zip";
var serializer = new XmlSerializer(typeof(EntityXML));
Response.Clear();
Response.ClearContent();
Response.ClearHeaders();
Response.AddHeader("content-disposition", "attachment;filename=" + nameDownloadZip);
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry(nameDownloadXml);
using (var entryStream = demoFile.Open())
using (StreamWriter writer = new StreamWriter(entryStream, System.Text.Encoding.UTF8))
{
serializer.Serialize(writer, xml);
}
}
using (var fileStream = Response.OutputStream)
{
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}
}
Response.End();
}
X
XPD
Function to return stream that contain zip file
public static Stream ZipGenerator(List<string> files)
{
ZipArchiveEntry fileInArchive;
Stream entryStream;
int i = 0;
List<byte[]> byteArray = new List<byte[]>();
foreach (var file in files)
{
byteArray.Add(File.ReadAllBytes(file));
}
var outStream = new MemoryStream();
using (var archive = new ZipArchive(outStream, ZipArchiveMode.Create, true))
{
foreach (var file in files)
{
fileInArchive=(archive.CreateEntry(Path.GetFileName(file), CompressionLevel.Optimal));
using (entryStream = fileInArchive.Open())
{
using (var fileToCompressStream = new MemoryStream(byteArray[i]))
{
fileToCompressStream.CopyTo(entryStream);
}
i++;
}
}
}
outStream.Position = 0;
return outStream;
}
If you want , write zip to file stream.
using (var fileStream = new FileStream(@"D:\Tools\DBExtractor\DBExtractor\bin\Debug\test.zip", FileMode.Create))
{
outStream.Position = 0;
outStream.WriteTo(fileStream);
}
`
Reading all files into memory first is huge waste of memory. You end up with all files twice in memory. Once in the
byteArray and once in the ZipArchive. Not to mention that you do not need to load files to memory at all. Use streaming, as shown in all the other existing answers.
@MartinPrikryl Question is way to write zip file into memory. thats why i use memory . of course the best way is write into local
I know what question is about. The point of my comment is that your implementation of creating a ZIP file in memory is hugely inefficient. The implementations in other answers are better.
As with any code on StackOverflow, this code must be refactored to suit your needs. After trying the solutions outlined in the other answers to no avail, I was able to get a solution from this answer quickly, then refactor the code to take out the redundancies.
c
cool_php
Just in case, if anyone wants to save a dynamic zip file through SaveFileDialog.
var logFileName = "zip_filename.zip";
appLogSaver.FileName = logFileName;
appLogSaver.Filter = "LogFiles|*.zip";
appLogSaver.DefaultExt = "zip";
DialogResult resDialog = appLogSaver.ShowDialog();
if (resDialog.ToString() == "OK")
{
System.IO.FileStream fs = (System.IO.FileStream)appLogSaver.OpenFile();
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
{
using (var streamWriter = new StreamWriter(entryStream))
{
//read your existing file and put the content here
streamWriter.Write("Bar!");
}
}
var demoFile2 = archive.CreateEntry("foo2.txt");
using (var entryStream = demoFile2.Open())
{
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar2!");
}
}
}
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fs);
}
fs.Close();
}
D
Dina Bogdan
For me something like this was ok:
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var file = archive.CreateEntry("file.json");
using var entryStream = file.Open();
using var streamWriter = new StreamWriter(entryStream);
streamWriter.WriteLine(someJsonLine);
}
}
a
aliastitan
private void button6_Click(object sender, EventArgs e)
{
//create With Input FileNames
AddFileToArchive_InputByte(new ZipItem[]{ new ZipItem( @"E:\b\1.jpg",@"images\1.jpg"),
new ZipItem(@"E:\b\2.txt",@"text\2.txt")}, @"C:\test.zip");
//create with input stream
AddFileToArchive_InputByte(new ZipItem[]{ new ZipItem(File.ReadAllBytes( @"E:\b\1.jpg"),@"images\1.jpg"),
new ZipItem(File.ReadAllBytes(@"E:\b\2.txt"),@"text\2.txt")}, @"C:\test.zip");
//Create Archive And Return StreamZipFile
MemoryStream GetStreamZipFile = AddFileToArchive(new ZipItem[]{ new ZipItem( @"E:\b\1.jpg",@"images\1.jpg"),
new ZipItem(@"E:\b\2.txt",@"text\2.txt")});
//Extract in memory
ZipItem[] ListitemsWithBytes = ExtractItems(@"C:\test.zip");
//Choese Files For Extract To memory
List<string> ListFileNameForExtract = new List<string>(new string[] { @"images\1.jpg", @"text\2.txt" });
ListitemsWithBytes = ExtractItems(@"C:\test.zip", ListFileNameForExtract);
// Choese Files For Extract To Directory
ExtractItems(@"C:\test.zip", ListFileNameForExtract, "c:\\extractFiles");
}
public struct ZipItem
{
string _FileNameSource;
string _PathinArchive;
byte[] _Bytes;
public ZipItem(string __FileNameSource, string __PathinArchive)
{
_Bytes=null ;
_FileNameSource = __FileNameSource;
_PathinArchive = __PathinArchive;
}
public ZipItem(byte[] __Bytes, string __PathinArchive)
{
_Bytes = __Bytes;
_FileNameSource = "";
_PathinArchive = __PathinArchive;
}
public string FileNameSource
{
set
{
FileNameSource = value;
}
get
{
return _FileNameSource;
}
}
public string PathinArchive
{
set
{
_PathinArchive = value;
}
get
{
return _PathinArchive;
}
}
public byte[] Bytes
{
set
{
_Bytes = value;
}
get
{
return _Bytes;
}
}
}
public void AddFileToArchive(ZipItem[] ZipItems, string SeveToFile)
{
MemoryStream memoryStream = new MemoryStream();
//Create Empty Archive
ZipArchive archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true);
foreach (ZipItem item in ZipItems)
{
//Create Path File in Archive
ZipArchiveEntry FileInArchive = archive.CreateEntry(item.PathinArchive);
//Open File in Archive For Write
var OpenFileInArchive = FileInArchive.Open();
//Read Stream
FileStream fsReader = new FileStream(item.FileNameSource, FileMode.Open, FileAccess.Read);
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 0;
while (fsReader.Position != fsReader.Length)
{
//Read Bytes
ReadByte = fsReader.Read(ReadAllbytes, 0, ReadAllbytes.Length);
//Write Bytes
OpenFileInArchive.Write(ReadAllbytes, 0, ReadByte);
}
fsReader.Dispose();
OpenFileInArchive.Close();
}
archive.Dispose();
using (var fileStream = new FileStream(SeveToFile, FileMode.Create))
{
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}
}
public MemoryStream AddFileToArchive(ZipItem[] ZipItems)
{
MemoryStream memoryStream = new MemoryStream();
//Create Empty Archive
ZipArchive archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true);
foreach (ZipItem item in ZipItems)
{
//Create Path File in Archive
ZipArchiveEntry FileInArchive = archive.CreateEntry(item.PathinArchive);
//Open File in Archive For Write
var OpenFileInArchive = FileInArchive.Open();
//Read Stream
FileStream fsReader = new FileStream(item.FileNameSource, FileMode.Open, FileAccess.Read);
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 0;
while (fsReader.Position != fsReader.Length)
{
//Read Bytes
ReadByte = fsReader.Read(ReadAllbytes, 0, ReadAllbytes.Length);
//Write Bytes
OpenFileInArchive.Write(ReadAllbytes, 0, ReadByte);
}
fsReader.Dispose();
OpenFileInArchive.Close();
}
archive.Dispose();
return memoryStream;
}
public void AddFileToArchive_InputByte(ZipItem[] ZipItems, string SeveToFile)
{
MemoryStream memoryStream = new MemoryStream();
//Create Empty Archive
ZipArchive archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true);
foreach (ZipItem item in ZipItems)
{
//Create Path File in Archive
ZipArchiveEntry FileInArchive = archive.CreateEntry(item.PathinArchive);
//Open File in Archive For Write
var OpenFileInArchive = FileInArchive.Open();
//Read Stream
// FileStream fsReader = new FileStream(item.FileNameSource, FileMode.Open, FileAccess.Read);
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 4096 ;int TotalWrite=0;
while (TotalWrite != item.Bytes.Length)
{
if(TotalWrite+4096>item.Bytes.Length)
ReadByte=item.Bytes.Length-TotalWrite;
Array.Copy(item.Bytes, TotalWrite, ReadAllbytes, 0, ReadByte);
//Write Bytes
OpenFileInArchive.Write(ReadAllbytes, 0, ReadByte);
TotalWrite += ReadByte;
}
OpenFileInArchive.Close();
}
archive.Dispose();
using (var fileStream = new FileStream(SeveToFile, FileMode.Create))
{
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}
}
public MemoryStream AddFileToArchive_InputByte(ZipItem[] ZipItems)
{
MemoryStream memoryStream = new MemoryStream();
//Create Empty Archive
ZipArchive archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true);
foreach (ZipItem item in ZipItems)
{
//Create Path File in Archive
ZipArchiveEntry FileInArchive = archive.CreateEntry(item.PathinArchive);
//Open File in Archive For Write
var OpenFileInArchive = FileInArchive.Open();
//Read Stream
// FileStream fsReader = new FileStream(item.FileNameSource, FileMode.Open, FileAccess.Read);
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 4096 ;int TotalWrite=0;
while (TotalWrite != item.Bytes.Length)
{
if(TotalWrite+4096>item.Bytes.Length)
ReadByte=item.Bytes.Length-TotalWrite;
Array.Copy(item.Bytes, TotalWrite, ReadAllbytes, 0, ReadByte);
//Write Bytes
OpenFileInArchive.Write(ReadAllbytes, 0, ReadByte);
TotalWrite += ReadByte;
}
OpenFileInArchive.Close();
}
archive.Dispose();
return memoryStream;
}
public void ExtractToDirectory(string sourceArchiveFileName, string destinationDirectoryName)
{
//Opens the zip file up to be read
using (ZipArchive archive = ZipFile.OpenRead(sourceArchiveFileName))
{
if (Directory.Exists(destinationDirectoryName)==false )
Directory.CreateDirectory(destinationDirectoryName);
//Loops through each file in the zip file
archive.ExtractToDirectory(destinationDirectoryName);
}
}
public void ExtractItems(string sourceArchiveFileName,List< string> _PathFilesinArchive, string destinationDirectoryName)
{
//Opens the zip file up to be read
using (ZipArchive archive = ZipFile.OpenRead(sourceArchiveFileName))
{
//Loops through each file in the zip file
foreach (ZipArchiveEntry file in archive.Entries)
{
int PosResult = _PathFilesinArchive.IndexOf(file.FullName);
if (PosResult != -1)
{
//Create Folder
if (Directory.Exists( destinationDirectoryName + "\\" +Path.GetDirectoryName( _PathFilesinArchive[PosResult])) == false)
Directory.CreateDirectory(destinationDirectoryName + "\\" + Path.GetDirectoryName(_PathFilesinArchive[PosResult]));
Stream OpenFileGetBytes = file.Open();
FileStream FileStreamOutput = new FileStream(destinationDirectoryName + "\\" + _PathFilesinArchive[PosResult], FileMode.Create);
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 0; int TotalRead = 0;
while (TotalRead != file.Length)
{
//Read Bytes
ReadByte = OpenFileGetBytes.Read(ReadAllbytes, 0, ReadAllbytes.Length);
TotalRead += ReadByte;
//Write Bytes
FileStreamOutput.Write(ReadAllbytes, 0, ReadByte);
}
FileStreamOutput.Close();
OpenFileGetBytes.Close();
_PathFilesinArchive.RemoveAt(PosResult);
}
if (_PathFilesinArchive.Count == 0)
break;
}
}
}
public ZipItem[] ExtractItems(string sourceArchiveFileName)
{
List< ZipItem> ZipItemsReading = new List<ZipItem>();
//Opens the zip file up to be read
using (ZipArchive archive = ZipFile.OpenRead(sourceArchiveFileName))
{
//Loops through each file in the zip file
foreach (ZipArchiveEntry file in archive.Entries)
{
Stream OpenFileGetBytes = file.Open();
MemoryStream memstreams = new MemoryStream();
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 0; int TotalRead = 0;
while (TotalRead != file.Length)
{
//Read Bytes
ReadByte = OpenFileGetBytes.Read(ReadAllbytes, 0, ReadAllbytes.Length);
TotalRead += ReadByte;
//Write Bytes
memstreams.Write(ReadAllbytes, 0, ReadByte);
}
memstreams.Position = 0;
OpenFileGetBytes.Close();
memstreams.Dispose();
ZipItemsReading.Add(new ZipItem(memstreams.ToArray(),file.FullName));
}
}
return ZipItemsReading.ToArray();
}
public ZipItem[] ExtractItems(string sourceArchiveFileName,List< string> _PathFilesinArchive)
{
List< ZipItem> ZipItemsReading = new List<ZipItem>();
//Opens the zip file up to be read
using (ZipArchive archive = ZipFile.OpenRead(sourceArchiveFileName))
{
//Loops through each file in the zip file
foreach (ZipArchiveEntry file in archive.Entries)
{
int PosResult = _PathFilesinArchive.IndexOf(file.FullName);
if (PosResult!= -1)
{
Stream OpenFileGetBytes = file.Open();
MemoryStream memstreams = new MemoryStream();
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 0; int TotalRead = 0;
while (TotalRead != file.Length)
{
//Read Bytes
ReadByte = OpenFileGetBytes.Read(ReadAllbytes, 0, ReadAllbytes.Length);
TotalRead += ReadByte;
//Write Bytes
memstreams.Write(ReadAllbytes, 0, ReadByte);
}
//Create item
ZipItemsReading.Add(new ZipItem(memstreams.ToArray(),file.FullName));
OpenFileGetBytes.Close();
memstreams.Dispose();
_PathFilesinArchive.RemoveAt(PosResult);
}
if (_PathFilesinArchive.Count == 0)
break;
}
}
return ZipItemsReading.ToArray();
}
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