ZipArchive Class

Definition

Namespace:

System.IO.Compression

Assembly:

System.IO.Compression.dll

Source:

ZipArchive.cs

Represents a package of compressed files in the zip archive format.

public ref class ZipArchive : IDisposable

public class ZipArchive : IDisposable

type ZipArchive = class
    interface IDisposable

Public Class ZipArchive
Implements IDisposable

Inheritance

Object

ZipArchive

Implements

IDisposable

Remarks

The methods for manipulating zip archives and their file entries are spread across three classes: ZipFile, ZipArchive, and ZipArchiveEntry.

To	Use
Create a zip archive from a directory	ZipFile.CreateFromDirectory
Extract the contents of a zip archive to a directory	ZipFile.ExtractToDirectory
Add new files to an existing zip archive	ZipArchive.CreateEntry
Retrieve a file from a zip archive	ZipArchive.GetEntry
Retrieve all the files from a zip archive	ZipArchive.Entries
Open a stream to a single file contained in a zip archive	ZipArchiveEntry.Open
Delete a file from a zip archive	ZipArchiveEntry.Delete

When you create a new entry, the file is compressed and added to the zip package. The CreateEntry method enables you to specify a directory hierarchy when adding the entry. You include the relative path of the new entry within the zip package. For example, creating a new entry with a relative path of AddedFolder\NewFile.txt creates a compressed text file in a directory named AddedFolder.

If you reference the System.IO.Compression.FileSystem assembly in your project, you can access four extension methods (from the ZipFileExtensions class) for the ZipArchive class: CreateEntryFromFile(ZipArchive, String, String), CreateEntryFromFile(ZipArchive, String, String, CompressionLevel), ExtractToDirectory(ZipArchive, String), and ExtractToDirectory(ZipArchive, String, Boolean) (available in .NET Core 2.0 and later versions). These extension methods enable you to compress and decompress the contents of the entry to a file. The System.IO.Compression.FileSystem assembly is not available for Windows 8.x Store apps. In Windows 8.x Store apps, you can compress and decompress files by using the DeflateStream or GZipStream class, or you can use the Windows Runtime types Compressor and Decompressor.

Examples

The first example shows how to create a new entry and write to it by using a stream.

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

namespace ConsoleApplication
{
    class Program
    {
        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("========================");
                    }
                }
            }
        }
    }
}

Imports System.IO
Imports System.IO.Compression

Module Module1

    Sub Main()
        Using zipToOpen As FileStream = New FileStream("c:\users\exampleuser\release.zip", FileMode.Open)
            Using archive As ZipArchive = New ZipArchive(zipToOpen, ZipArchiveMode.Update)
                Dim readmeEntry As ZipArchiveEntry = archive.CreateEntry("Readme.txt")
                Using writer As StreamWriter = New StreamWriter(readmeEntry.Open())
                    writer.WriteLine("Information about this package.")
                    writer.WriteLine("========================")
                End Using
            End Using
        End Using
    End Sub

End Module

The following example shows how to open a zip archive and iterate through the collection of entries.

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

class Program
{
    static void Main(string[] args)
    {
        string zipPath = @".\result.zip";

        Console.WriteLine("Provide path where to extract the zip file:");
        string extractPath = Console.ReadLine();

        // Normalizes the path.
        extractPath = Path.GetFullPath(extractPath);

        // Ensures that the last character on the extraction path
        // is the directory separator char.
        // Without this, a malicious zip file could try to traverse outside of the expected
        // extraction path.
        if (!extractPath.EndsWith(Path.DirectorySeparatorChar.ToString(), StringComparison.Ordinal))
            extractPath += Path.DirectorySeparatorChar;

        using (ZipArchive archive = ZipFile.OpenRead(zipPath))
        {
            foreach (ZipArchiveEntry entry in archive.Entries)
            {
                if (entry.FullName.EndsWith(".txt", StringComparison.OrdinalIgnoreCase))
                {
                    // Gets the full path to ensure that relative segments are removed.
                    string destinationPath = Path.GetFullPath(Path.Combine(extractPath, entry.FullName));

                    // Ordinal match is safest, case-sensitive volumes can be mounted within volumes that
                    // are case-insensitive.
                    if (destinationPath.StartsWith(extractPath, StringComparison.Ordinal))
                        entry.ExtractToFile(destinationPath);
                }
            }
        }
    }
}

Imports System.IO
Imports System.IO.Compression

Module Module1

    Sub Main()
        Dim zipPath As String = ".\result.zip"

        Console.WriteLine("Provide path where to extract the zip file:")
        Dim extractPath As String = Console.ReadLine()

        ' Normalizes the path.
        extractPath = Path.GetFullPath(extractPath)

        ' Ensures that the last character on the extraction path
        ' is the directory separator char. 
        ' Without this, a malicious zip file could try to traverse outside of the expected
        ' extraction path.
        If Not extractPath.EndsWith(Path.DirectorySeparatorChar.ToString(), StringComparison.Ordinal) Then
            extractPath += Path.DirectorySeparatorChar
        End If

        Using archive As ZipArchive = ZipFile.OpenRead(zipPath)
            For Each entry As ZipArchiveEntry In archive.Entries
                If entry.FullName.EndsWith(".txt", StringComparison.OrdinalIgnoreCase) Then

                    ' Gets the full path to ensure that relative segments are removed.
                    Dim destinationPath As String = Path.GetFullPath(Path.Combine(extractPath, entry.FullName))
                    
                    ' Ordinal match is safest, case-sensitive volumes can be mounted within volumes that
                    ' are case-insensitive.
                    If destinationPath.StartsWith(extractPath, StringComparison.Ordinal) Then 
                        entry.ExtractToFile(destinationPath)
                    End If

                End If
            Next
        End Using
    End Sub

End Module

The third example shows how to use extension methods to create a new entry in a zip archive from an existing file and extract the archive contents. You must reference the System.IO.Compression.FileSystem assembly to execute the code.

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

namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            string zipPath = @"c:\users\exampleuser\start.zip";
            string extractPath = @"c:\users\exampleuser\extract";
            string newFile = @"c:\users\exampleuser\NewFile.txt";

            using (ZipArchive archive = ZipFile.Open(zipPath, ZipArchiveMode.Update))
            {
                archive.CreateEntryFromFile(newFile, "NewEntry.txt");
                archive.ExtractToDirectory(extractPath);
            }
        }
    }
}

Imports System.IO
Imports System.IO.Compression

Module Module1

    Sub Main()
        Dim zipPath As String = "c:\users\exampleuser\end.zip"
        Dim extractPath As String = "c:\users\exampleuser\extract"
        Dim newFile As String = "c:\users\exampleuser\NewFile.txt"

        Using archive As ZipArchive = ZipFile.Open(zipPath, ZipArchiveMode.Update)
            archive.CreateEntryFromFile(newFile, "NewEntry.txt", CompressionLevel.Fastest)
            archive.ExtractToDirectory(extractPath)
        End Using
    End Sub

End Module

Constructors

ZipArchive(Stream, ZipArchiveMode, Boolean, Encoding)	Initializes a new instance of the ZipArchive class on the specified stream for the specified mode, uses the specified encoding for entry names, and optionally leaves the stream open.
ZipArchive(Stream, ZipArchiveMode, Boolean)	Initializes a new instance of the ZipArchive class on the specified stream for the specified mode, and optionally leaves the stream open.
ZipArchive(Stream, ZipArchiveMode)	Initializes a new instance of the ZipArchive class from the specified stream and with the specified mode.
ZipArchive(Stream)	Initializes a new instance of the ZipArchive class from the specified stream.

Properties

Comment	Gets or sets the optional archive comment.
Entries	Gets the collection of entries that are currently in the zip archive.
Mode	Gets a value that describes the type of action the zip archive can perform on entries.

Methods

CreateEntry(String, CompressionLevel)	Creates an empty entry that has the specified entry name and compression level in the zip archive.
CreateEntry(String)	Creates an empty entry that has the specified path and entry name in the zip archive.
Dispose()	Releases the resources used by the current instance of the ZipArchive class.
Dispose(Boolean)	Called by the Dispose() and Finalize() methods to release the unmanaged resources used by the current instance of the ZipArchive class, and optionally finishes writing the archive and releases the managed resources.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetEntry(String)	Retrieves a wrapper for the specified entry in the zip archive.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

Extension Methods

CreateEntryFromFile(ZipArchive, String, String, CompressionLevel)	Archives a file by compressing it using the specified compression level and adding it to the zip archive.
CreateEntryFromFile(ZipArchive, String, String)	Archives a file by compressing it and adding it to the zip archive.
ExtractToDirectory(ZipArchive, String, Boolean)	Extracts all of the files in the archive to a directory on the file system.
ExtractToDirectory(ZipArchive, String)	Extracts all the files in the zip archive to a directory on the file system.

See also

• ZipFile