Question

I have a program which needs to download multiple files at once. I can download a single file by using this single file download, but it doesn’t work for multiple.

How can one download multiple files at once in such as as zip file?

Answer 1

You need to pack files and write a result to a response.
You can use SharpZipLib compression library.

Code example:

Response.AddHeader("Content-Disposition", "attachment; filename=" + compressedFileName + ".zip");
Response.ContentType = "application/zip";

using (var zipStream = new ZipOutputStream(Response.OutputStream))
{
    foreach (string filePath in filePaths)
    {
        byte[] fileBytes = System.IO.File.ReadAllBytes(filePath);

        var fileEntry = new ZipEntry(Path.GetFileName(filePath))
        {
            Size = fileBytes.Length
        };

        zipStream.PutNextEntry(fileEntry);
        zipStream.Write(fileBytes, 0, fileBytes.Length);
    }

    zipStream.Flush();
    zipStream.Close();
}