.NET Framework Reading and writing Zip files Updating a ZIP file
Example
To update a ZIP file, the file has to be opened with ZipArchiveMode.Update instead.
using (FileStream fs = new FileStream("archive.zip", FileMode.Open))
using (ZipArchive archive = new ZipArchive(fs, ZipArchiveMode.Update))
{
// Add file to root
archive.CreateEntryFromFile("test.txt", "test.txt");
// Add file to subfolder
archive.CreateEntryFromFile("test.txt", "symbols/test.txt");
}
There is also the option to write directly to a file within the archive:
var entry = archive.CreateEntry("createentry.txt");
using(var writer = new StreamWriter(entry.Open()))
{
writer.WriteLine("Test line");
}
