ZipFile.OpenRead Method (String)

.NET Framework (current version)

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Opens a zip archive for reading at the specified path.

Namespace:   System.IO.Compression
Assembly:  System.IO.Compression.FileSystem (in System.IO.Compression.FileSystem.dll)

public static ZipArchive OpenRead(
	string archiveFileName


Type: System.String

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.

Return Value

Type: System.IO.Compression.ZipArchive

The opened zip archive.

Exception Condition

archiveFileName is Empty, contains only white space, or contains at least one invalid character.


archiveFileName is null.


In archiveFileName, the specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must not exceed 248 characters, and file names must not exceed 260 characters.


archiveFileName is invalid or does not exist (for example, it is on an unmapped drive).


archiveFileName could not be opened.


archiveFileName specifies a directory.


The caller does not have the required permission to access the file specified in archiveFileName.


The file specified in archiveFileName is not found.


archiveFileName contains an invalid format.


archiveFileName could not be interpreted as a zip archive.

This method is equivalent to calling the Open method and setting the mode parameter to Read. The archive is opened with FileMode.Open as the file mode value. If the archive does not exist, a FileNotFoundException exception is thrown.

The following example shows how to open a zip archive for reading.

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

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

Universal Windows Platform
Available since 10
.NET Framework
Available since 4.5
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