ZipArchiveEntry Class

Definition

Namespace:

System.IO.Compression

Assembly:

System.IO.Compression.dll

Source:

ZipArchiveEntry.cs

Represents a compressed file within a zip archive.

public ref class ZipArchiveEntry

public class ZipArchiveEntry

type ZipArchiveEntry = class

Public Class ZipArchiveEntry

Inheritance

Object

ZipArchiveEntry

Remarks

A zip archive contains an entry for each compressed file. The ZipArchiveEntry class enables you to examine the properties of an entry, and open or delete the entry. When you open an entry, you can modify the compressed file by writing to the stream for that compressed file.

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 in a zip archive	ZipArchive.GetEntry
Retrieve all of the files in a zip archive	ZipArchive.Entries
To open a stream to an individual file contained in a zip archive	ZipArchiveEntry.Open
Delete a file from a zip archive	ZipArchiveEntry.Delete

If you reference the System.IO.Compression.FileSystem assembly in your project, you can access two extension methods for the ZipArchiveEntry class. Those methods are ExtractToFile(ZipArchiveEntry, String) and ExtractToFile(ZipArchiveEntry, String, Boolean), and they enable you to decompress the contents of the entry to a file. The System.IO.Compression.FileSystem assembly is not available in Windows 8. In Windows 8.x Store apps, you can decompress the contents of an archive by using DeflateStream or GZipStream, or you can use the Windows Runtime types Compressor and Decompressor to compress and decompress files.

Examples

The first example shows how to create a new entry in a zip archive and write to it.

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 second example shows how to use the ExtractToFile(ZipArchiveEntry, String) extension method. You must reference the System.IO.Compression.FileSystem assembly in your project for the code to execute.

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

Properties

Archive	Gets the zip archive that the entry belongs to.
Comment	Gets or sets the optional entry comment.
CompressedLength	Gets the compressed size, expressed in bytes, of the entry in the zip archive.
Crc32	The 32-bit Cyclic Redundant Check.
ExternalAttributes	OS and application specific file attributes.
FullName	Gets the relative path of the entry in the zip archive.
IsEncrypted	Gets a value that indicates whether the entry is encrypted.
LastWriteTime	Gets or sets the last time the entry in the zip archive was changed.
Length	Gets the uncompressed size, expressed in bytes, of the entry in the zip archive.
Name	Gets the file name of the entry in the zip archive.

Methods

Delete()	Deletes the entry from the zip archive.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
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)
Open()	Opens the entry from the zip archive.
ToString()	Retrieves the relative path of the entry in the zip archive.

Extension Methods

ExtractToFile(ZipArchiveEntry, String, Boolean)	Extracts an entry in the zip archive to a file, and optionally overwrites an existing file that has the same name.
ExtractToFile(ZipArchiveEntry, String)	Extracts an entry in the zip archive to a file.