Creating Directories in a ZipArchive C# .Net 4.5

Question

A ZipArchive is a collection of ZipArchiveEntries, and adding/removing \"Entries\" works nicely. But it appears there is no notion of directories / nested \"Archives\". In t

Answer 1

I don't like recursion as it was proposed by @Val, @sDima, @Nitheesh. Potentially it leads to the StackOverflowException because the stack has limited size. So here is my two cents with tree traversal.

public static class ZipArchiveExtensions
{
    public static void CreateEntryFromDirectory(this ZipArchive archive, string sourceDirName, CompressionLevel compressionLevel = CompressionLevel.Fastest)
    {
        var folders = new Stack<string>();
        folders.Push(sourceDirName);
        
        do
        {
            var currentFolder = folders.Pop();
            Directory.GetFiles(currentFolder).ForEach(f => archive.CreateEntryFromFile(f, f.Substring(sourceDirName.Length+1), compressionLevel));
            Directory.GetDirectories(currentFolder).ForEach(d => folders.Push(d));
        } while (folders.Count > 0);
    }
}

Answer 2

I was also looking for a similar solution and found @Val & @sDima's solution more promising to me. But I found some issues with the code and fixed them to use with my code.

Like @sDima, I also decided to use Extension to add more functionality to ZipArchive.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO.Compression;
using System.IO;

namespace ZipTest
{
   public static class ZipArchiveExtensions
   {
      public static void CreateEntryFromAny(this ZipArchive archive, string sourceName, string entryName, CompressionLevel compressionLevel = CompressionLevel.Optimal)
    {
        try
        {
            if (File.GetAttributes(sourceName).HasFlag(FileAttributes.Directory))
            {
                archive.CreateEntryFromDirectory(sourceName, entryName, compressionLevel);
            }
            else
            {
                archive.CreateEntryFromFile(sourceName, entryName, compressionLevel);
            }
        }
        catch
        {
            throw;
        }
    }

    public static void CreateEntryFromDirectory(this ZipArchive archive, string sourceDirName, string entryName, CompressionLevel compressionLevel)
    {
        try
        {
            var files = Directory.EnumerateFileSystemEntries(sourceDirName);
            if (files.Any())
            {
                foreach (var file in files)
                {
                    var fileName = Path.GetFileName(file);
                    archive.CreateEntryFromAny(file, Path.Combine(entryName, fileName), compressionLevel);
                }
            }
            else
            {
                //Do a folder entry check.
                if (!string.IsNullOrEmpty(entryName) && entryName[entryName.Length - 1] != '/')
                {
                    entryName += "/";
                }

                archive.CreateEntry(entryName, compressionLevel);
            }
        }
        catch
        {
            throw;
        }
      }
    }
  }

You can try the extension using the simple given below,

 class Program
 {
    static void Main(string[] args)
    {
        string filePath = @"C:\Users\WinUser\Downloads\Test.zip";
        string dirName = Path.GetDirectoryName(filePath);
       
        if (File.Exists(filePath))
            File.Delete(filePath);

        using (ZipArchive archive = ZipFile.Open(filePath, ZipArchiveMode.Create))
        {
            archive.CreateEntryFromFile( @"C:\Users\WinUser\Downloads\file1.jpg", "SomeFolder/file1.jpg", CompressionLevel.Optimal);
            archive.CreateEntryFromDirectory(@"C:\Users\WinUser\Downloads\MyDocs", "OfficeDocs", CompressionLevel.Optimal);
            archive.CreateEntryFromAny(@"C:\Users\WinUser\Downloads\EmptyFolder", "EmptyFolder", CompressionLevel.Optimal);
        };

        using (ZipArchive zip = ZipFile.OpenRead(filePath))
        {
            string dirExtract = @"C:\Users\WinUser\Downloads\Temp";
            if (Directory.Exists(dirExtract))
            {
                Directory.Delete(dirExtract, true);
            }

            zip.ExtractToDirectory(dirExtract);
        }
     }
   }

I tried to keep the exact behavior of standard CreateEntryFromFilefrom the .Net Framework for extension methods.

To use the sample code given, add a reference to System.IO.Compression.dll and System.IO.Compression.FileSystem.dll.

Following are the advantages of this extension class

1. Recursive adding of folder content.
2. Support for an empty folder.