Scroll to top

C# Language : Reading and writing .zip files


Curious Bot - December 1, 2018 - 0 comments

Writing to a zip file

To write a new .zip file:

System.IO.Compression
System.IO.Compression.FileSystem

using (FileStream zipToOpen = new FileStream(@"C:\temp", 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("========================");
}
}
}

Writing Zip Files in-memory

The following example will return the byte[] data of a zipped file containing the files provided to it, without needing access to the file system.

public static byte[] ZipFiles(Dictionary<string, byte[]> files)
{
using (MemoryStream ms = new MemoryStream())
{
using (ZipArchive archive = new ZipArchive(ms, ZipArchiveMode.Update))
{
foreach (var file in files)
{
ZipArchiveEntry orderEntry = archive.CreateEntry(file.Key); //create a file with this name
using (BinaryWriter writer = new BinaryWriter(orderEntry.Open()))
{
writer.Write(file.Value); //write the binary data
}
}
}
//ZipArchive must be disposed before the MemoryStream has data
return ms.ToArray();
}
}

Get files from a Zip file

This example gets a listing of files from the provided zip archive binary data:

public static Dictionary<string, byte[]> GetFiles(byte[] zippedFile)
{
using (MemoryStream ms = new MemoryStream(zippedFile))
using (ZipArchive archive = new ZipArchive(ms, ZipArchiveMode.Read))
{
return archive.Entries.ToDictionary(x => x.FullName, x => ReadStream(x.Open()));
}
}

private static byte[] ReadStream(Stream stream)
{
using (var ms = new MemoryStream())
{
stream.CopyTo(ms);
return ms.ToArray();
}
}

The following example shows how to open a zip archive and extract all .txt files to a folder

using System;
using System.IO;
using System.IO.Compression;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string zipPath = @"c:\example\start.zip";
string extractPath = @"c:\example\extract";

using (ZipArchive archive = ZipFile.OpenRead(zipPath))
{
foreach (ZipArchiveEntry entry in archive.Entries)
{
if (entry.FullName.EndsWith(".txt", StringComparison.OrdinalIgnoreCase))
{
entry.ExtractToFile(Path.Combine(extractPath, entry.FullName));
}
}
}
}
}
}

Parameters

Parameter Details
archiveFileName The path to the archive to open, specified as a relative or absolute path. A relative path is interpreted as relative to the current working directory.

Syntax

  1. public static ZipArchive OpenRead(string archiveFileName)

Related posts