Streaming a zip file over http in .net with SharpZipLib

Question

I\'m making a simple download service so a user can download all his images from out site. To do that i just zip everything to the http stream.

However it seems ever

Answer 1

use Response.BufferOutput = false; at start of ProcessRequest and flush response after each file.

Answer 2

FYI. This is working code to recursively add an entire tree of files, with streaming to browser:

string path = @"c:\files";

Response.Clear();
Response.ContentType = "application/zip";
Response.AddHeader("Content-Disposition", string.Format("attachment; filename=\"{0}\"", "hive.zip"));
Response.BufferOutput = false;

byte[] buffer = new byte[1024 * 1024];
using (ZipOutputStream zo = new ZipOutputStream(Response.OutputStream, 1024 * 1024)) {
    zo.SetLevel(0);
    DirectoryInfo di = new DirectoryInfo(path);
    foreach (string file in Directory.GetFiles(di.FullName, "*.*", SearchOption.AllDirectories)) {
        string folder = Path.GetDirectoryName(file);
        if (folder.Length > di.FullName.Length) {
            folder = folder.Substring(di.FullName.Length).Trim('\\') + @"\";
        } else {
            folder = string.Empty;
        }
        zo.PutNextEntry(new ZipEntry(folder + Path.GetFileName(file)));
        using (FileStream fs = File.OpenRead(file)) {
            ICSharpCode.SharpZipLib.Core.StreamUtils.Copy(fs, zo, buffer);
        }
        zo.Flush();
        Response.Flush();
    }
    zo.Finish();
}

Response.Flush();

Answer 3

Disable response buffering with context.Response.BufferOutput = false; and remove the Flush call from the end of your code.