Create zip from multiple files in memory
I am trying to use SharpZipLib to create a zip file and let the client download it.
The current mail folder is created and available on the client machine, but the problem in the download.zip folder is empty. The files specified in the folder are not available in the zip folder.
Below is the code I have tried.
System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
ICSharpCode.SharpZipLib.Checksums.Crc32 crc = new ICSharpCode.SharpZipLib.Checksums.Crc32();
//stream directly to client.
ICSharpCode.SharpZipLib.Zip.ZipOutputStream output = new ICSharpCode.SharpZipLib.Zip.ZipOutputStream(response.OutputStream);
output.SetLevel(9);
string[] files = Directory.GetFiles("D:/newfolder/");
for (int i = 0; i < files.Length; i++)
{
ICSharpCode.SharpZipLib.Zip.ZipEntry entry = new ICSharpCode.SharpZipLib.Zip.ZipEntry(files[i].ToString());
entry.DateTime = DateTime.Now;
System.IO.FileStream fs = new System.IO.FileStream(files[i].ToString(), FileMode.Open);
byte[] buffer = new byte[fs.Length];
fs.Read(buffer, 0, buffer.Length);
entry.Size = fs.Length;
fs.Close();
crc.Reset();
crc.Update(buffer);
entry.Crc = crc.Value;
output.PutNextEntry(entry);
output.Write(buffer, 0, buffer.Length);
}
output.Finish();
output.Close();
response.Clear();
response.ContentType = "D:/Work Area/";
response.AddHeader("Content-Disposition", "attachment; filename=" + "download.zip");
response.End();
Can anyone tell me what the problem is? Why files are not available in .zip
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1 answer
After browsing the SharpDevelop wiki, I found the following that might help you solve this problem:
using ICSharpCode.SharpZipLib.Zip;
// This will accumulate each of the files named in the fileList into a zip file,
// and stream it to the browser.
// This approach writes directly to the Response OutputStream.
// The browser starts to receive data immediately which should avoid timeout problems.
// This also avoids an intermediate memorystream, saving memory on large files.
//
private void DownloadZipToBrowser(List <string> zipFileList)
{
Response.ContentType = "application/zip";
// If the browser is receiving a mangled zipfile, IIS Compression may cause this problem. Some members have found that
// Response.ContentType = "application/octet-stream" has solved this. May be specific to Internet Explorer.
Response.AppendHeader("content-disposition", "attachment; filename=\"Download.zip\"");
response.CacheControl = "Private";
response.Cache.SetExpires(DateTime.Now.AddMinutes(3)); // or put a timestamp in the filename in the content-disposition
byte[] buffer = new byte[4096];
ZipOutputStream zipOutputStream = new ZipOutputStream(Response.OutputStream);
zipOutputStream.SetLevel(3); //0-9, 9 being the highest level of compression
foreach (string fileName in zipFileList) {
Stream fs = File.OpenRead(fileName); // or any suitable inputstream
ZipEntry entry = new ZipEntry(ZipEntry.CleanName(fileName));
entry.Size = fs.Length;
// Setting the Size provides WinXP built-in extractor compatibility,
// but if not available, you can set zipOutputStream.UseZip64 = UseZip64.Off instead.
zipOutputStream.PutNextEntry(entry);
int count = fs.Read(buffer, 0, buffer.Length);
while (count > 0) {
zipOutputStream.Write(buffer, 0, count);
count = fs.Read(buffer, 0, buffer.Length);
if (!Response.IsClientConnected) {
break;
}
Response.Flush();
}
fs.Close();
}
zipOutputStream.Close();
Response.Flush();
Response.End();
}
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