Create Zip archive from multiple in memory files in C#

Question

Is there a way to create a Zip archive that contains multiple files, when the files are currently in memory? The files I want to save are really just text only and are stor

Answer 1

This function should create a byte array from a stream of data: I've created a simple interface for handling files for simplicity

public interface IHasDocumentProperties
{
    byte[] Content { get; set; }
    string Name { get; set; }
}

public void CreateZipFileContent(string filePath, IEnumerable<IHasDocumentProperties> fileInfos)
{    
    using (var memoryStream = new MemoryStream())
    {
        using (var zipArchive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
        {
            foreach(var fileInfo in fileInfos)
            {
                var entry = zipArchive.CreateEntry(fileInfo.Name);

                using (var entryStream = entry.Open())
                {
                    entryStream.Write(fileInfo.Content, 0, fileInfo.Content.Length);
                }                        
            }
        }

        using (var fileStream = new FileStream(filePath, FileMode.OpenOrCreate, System.IO.FileAccess.Write))
        {
            memoryStream.CopyTo(fileStream);
        }
    }
}

Answer 2

Note this answer is outdated; since .Net 4.5, the ZipArchive class allows zipping files in-memory. See johnny 5's answer below for how to use it.

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You could also do it a bit differently, using a Serializable object to store all strings

[Serializable]
public class MyStrings {
    public string Foo { get; set; }
    public string Bar { get; set; }
}

Then, you could serialize it into a stream to save it.
To save on space you could use GZipStream (From System.IO.Compression) to compress it. (note: GZip is stream compression, not an archive of multiple files).

That is, of course if what you need is actually to save data, and not zip a few files in a specific format for other software. Also, this would allow you to save many more types of data except strings.