ASP.NET Download All Files as Zip

Question

I have a folder on my web server that has hundreds of mp3 files in it. I would like to provide the option for a user to download a zipped archive of every mp3 in the directory from a web page.

I want to compress the files programmatically only when needed. Because the zip file will be quite large, I am thinking that I will need to send the zip file to the response stream as it is being zipped, for performance reasons.

Is this possible? How can I do it?

Answer 1

You could add a custom handler (.ashx file) that takes the file path, reads the file compresses it using a compression library and returns the bytes to the end user with the correct content-type.

Answer 2

I can't believe how easy this was. After reading this, here is the code that I used:

protected void Page_Load(object sender, EventArgs e)
{
    Response.Clear();
    Response.BufferOutput = false;
    Response.ContentType = "application/zip";
    Response.AddHeader("content-disposition", "attachment; filename=pauls_chapel_audio.zip");

    using (ZipFile zip = new ZipFile())
    {
        zip.CompressionLevel = CompressionLevel.None;
        zip.AddSelectedFiles("*.mp3", Server.MapPath("~/content/audio/"), "", false);
        zip.Save(Response.OutputStream);
    }

    Response.Close();
}

Answer 3

Here is code I use to do this with DotNetZip - works very well. Obviously you will need to provide the variables for outputFileName, folderName, and includeSubFolders.

response.ContentType = "application/zip";
response.AddHeader("content-disposition", "attachment; filename=" + outputFileName);
using (ZipFile zipfile = new ZipFile()) {
  zipfile.AddSelectedFiles("*.*", folderName, includeSubFolders);
  zipfile.Save(response.OutputStream);
}