ZipArchiveEntry ZipArchiveEntry ZipArchiveEntry ZipArchiveEntry Class

Definition

Represents a compressed file within a zip archive.

public ref class ZipArchiveEntry
public class ZipArchiveEntry
type ZipArchiveEntry = class
Public Class ZipArchiveEntry
Inheritance
ZipArchiveEntryZipArchiveEntryZipArchiveEntryZipArchiveEntry

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;

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

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 an 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.

Properties

Archive Archive Archive Archive

Gets the zip archive that the entry belongs to.

CompressedLength CompressedLength CompressedLength CompressedLength

Gets the compressed size of the entry in the zip archive.

Crc32 Crc32 Crc32 Crc32
ExternalAttributes ExternalAttributes ExternalAttributes ExternalAttributes

OS and application specific file attributes.

FullName FullName FullName FullName

Gets the relative path of the entry in the zip archive.

LastWriteTime LastWriteTime LastWriteTime LastWriteTime

Gets or sets the last time the entry in the zip archive was changed.

Length Length Length Length

Gets the uncompressed size of the entry in the zip archive.

Name Name Name Name

Gets the file name of the entry in the zip archive.

Methods

Delete() Delete() Delete() Delete()

Deletes the entry from the zip archive.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
Open() Open() Open() Open()

Opens the entry from the zip archive.

ToString() ToString() ToString() ToString()

Retrieves the relative path of the entry in the zip archive.

Extension Methods

ExtractToFile(ZipArchiveEntry, String) ExtractToFile(ZipArchiveEntry, String) ExtractToFile(ZipArchiveEntry, String) ExtractToFile(ZipArchiveEntry, String)

Extracts an entry in the zip archive to a file.

ExtractToFile(ZipArchiveEntry, String, Boolean) ExtractToFile(ZipArchiveEntry, String, Boolean) ExtractToFile(ZipArchiveEntry, String, Boolean) 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.

Applies to