ZipArchiveMode Enum

Definition

Namespace:

System.IO.Compression

Assembly:

System.IO.Compression.dll

Specifies values for interacting with zip archive entries.

public enum class ZipArchiveMode

public enum ZipArchiveMode

type ZipArchiveMode = 

Public Enum ZipArchiveMode

Inheritance

Object

ValueType

Enum

ZipArchiveMode

Fields

Name	Value	Description
Read	0	Only reading archive entries is permitted.
Create	1	Only creating new archive entries is permitted.
Update	2	Both read and write operations are permitted for archive entries.

Remarks

When you set the mode to Read, the underlying file or stream must support reading, but does not have to support seeking. If the underlying file or stream supports seeking, the files are read from the archive as they are requested. If the underlying file or stream does not support seeking, the entire archive is held in memory.

When you set the mode to Create, the underlying file or stream must support writing, but does not have to support seeking. Each entry in the archive can be opened only once for writing. If you create a single entry, the data is written to the underlying stream or file as soon as it is available. If you create multiple entries, such as by calling the CreateFromDirectory method, the data is written to the underlying stream or file after all the entries are created.

When you set the mode to Update, the underlying file or stream must support reading, writing, and seeking. The content of the entire archive is held in memory, and no data is written to the underlying file or stream until the archive is disposed.

The following methods include a parameter named mode that lets you specify the archive mode:

• ZipArchive.ZipArchive(Stream, ZipArchiveMode, Boolean)

• ZipArchive.ZipArchive(Stream, ZipArchiveMode)

• ZipFile.Open(String, ZipArchiveMode)

Examples

The following example shows how to specify a ZipArchiveMode value when creating a ZipArchive object.

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