Develop Reference

c# zip multiple files and download - can't open file in windows explorer

I use the SharpZipLib for zipping multiple files and download them in my asp.net c# web app. After the download I can't open the zip archive. Windows error message is:
Windows cannot open the folder. The Compressed (zipped) Folder 'filename.zip' is
invalid.
This is my code
if (Session["lstFilesToZip"] != null)
{
List<string> filesToZip = (List<string>)Session["lstFilesToZip"];
if (filesToZip.Count > 0)
{
Response.AddHeader("Content-Disposition", "attachment; filename=fileName.zip");
Response.ContentType = "application/zip";
using (var zipStream = new ZipOutputStream(Response.OutputStream))
{
foreach (string filePath in filesToZip)
{
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();
}
}
}
I already tried adding
zipStream.Dispose();
zipStream.Finish();
without success.
Maybe someone can help. I can't find the problem.

Create text files, compress them to a ZipArchive and present it for download

my scenario:
asp.net mvc web application
User clicks on a button in a view to start the action
Action:
Create several csv files from records that are stored in tables of an sql db
Compress all created files into a single ZipArchive
Present the ZipArchive for download to the client computer
I have a working code for creating a single csv file and presenting it for download.
public class ExportCSVController : BaseController
{
public ExportCSVController(IUnitOfWork unitOfWork)
{
UnitOfWork = unitOfWork;
}
public void ExportCSV_Company()
{
var sb = new StringBuilder();
var companies = UnitOfWork.GetAll<Company>();
var list = companies.ToList();
sb.AppendFormat("{0};{1};{2}{3};{4}", "Name", "Street", "City", "Zipcode", Environment.NewLine);
foreach (var item in list)
{
sb.AppendFormat("{0};{1};{2};{3};{4}", "\"" + item.Name + "\"", item.Street, item.City, item.Zip, Environment.NewLine);
}
//Get Current Response
var response = System.Web.HttpContext.Current.Response;
response.BufferOutput = true;
response.Clear();
response.ClearHeaders();
response.ContentEncoding = Encoding.Unicode;
response.AddHeader("content-disposition", "attachment;filename=Companies.txt ");
response.ContentType = "text/plain";
response.Write(sb.ToString());
response.End();
}
}
I also have a working code for compressing a file to a ZipArchive (using System.IO.Compression).
My idea:
Set up a loop (in my working code) for each file that needs to be generated
after generating the first file, add the file to the ZipArchive (using System.IO.Compression)
continue with the next file generation and append the file to the ZipArchive ...
then present the ZipArchive for download
My problem:
I do not quite understand where in the given code the file is generated, if at all?
I think, that response.Write() just directs the generated string to the browser where finally it is converted to a file when the user clicks on save.
Questions:
Must the response be saved to a file before it can be added to a ZipArchive?
If yes,
How would I convert the response via code to a file?
Is there any way to skip writing a physical file in order to get it into the ZipArchive?

Below, my example solution (for zipping 2 files)
public void ExportFilesToZip()
{
string zipFileName = "Test.zip";
string firstFileName = "FirstFile.txt";
string secondFileName = "SecondFile.txt";
string firstFileContent ="1";
string secondFileContent ="2";
Response.Clear();
Response.ClearContent();
Response.ClearHeaders();
Response.AddHeader("content-disposition", "attachment;filename=" + zipFileName);
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry(firstFileName);
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write(firstFileContent);
}
demoFile = archive.CreateEntry(secondFileName);
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write(secondFileContent);
}
}
using (var fileStream = Response.OutputStream)
{
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}
}
Response.End();
}

iTextSharp System.OutOfMemoryException

I have an issue with trying to create a large PDF file. Basically I have a list of byte arrays, each containing a PDF in a form of a byte array. I wanted to merge the byte arrays into a single PDF. This works great for smaller files (under 2000 pages), but when I tried creating a 12,00 page file it bombed). Originally I was using MemoryStream but after some research, a common solution was to use a FileStream instead. So I tried a file stream approach, however get similar results. The List contains 3,800 records, each containing 4 pages. MemoryStream bombs after around 570. FileStream after about 680 records. The current file size after the code crashed was 60MB. What am I doing wrong? Here is the code I have, and the code crashes on "copy.AddPage(curPg);" directive, inside the "for(" loop.
private byte[] MergePDFs(List<byte[]> PDFs)
{
iTextSharp.text.Document doc = new iTextSharp.text.Document();
byte[] completePDF;
Guid uniqueId = Guid.NewGuid();
string tempFileName = Server.MapPath("~/" + uniqueId.ToString() + ".pdf");
//using (MemoryStream ms = new MemoryStream())
using(FileStream ms = new FileStream(tempFileName, FileMode.Create, FileAccess.Write, FileShare.Read))
{
iTextSharp.text.pdf.PdfCopy copy = new iTextSharp.text.pdf.PdfCopy(doc, ms);
doc.Open();
int i = 0;
foreach (byte[] PDF in PDFs)
{
i++;
// Create a reader
iTextSharp.text.pdf.PdfReader reader = new iTextSharp.text.pdf.PdfReader(PDF);
// Cycle through all the pages
for (int currentPageNumber = 1; currentPageNumber <= reader.NumberOfPages; ++currentPageNumber)
{
// Read a page
iTextSharp.text.pdf.PdfImportedPage curPg = copy.GetImportedPage(reader, currentPageNumber);
// Add the page over to the rest of them
copy.AddPage(curPg);
}
// Close the reader
reader.Close();
}
// Close the document
doc.Close();
// Close the copier
copy.Close();
// Convert the memorystream to a byte array
//completePDF = ms.ToArray();
}
//return completePDF;
return GetPDFsByteArray(tempFileName);
}

A couple of notes:
PdfCopy implements iDisposable, so you should try and see if a using helps.
PdfCopy.FreeReader() will help.
Anyway, not sure if you're using MVC or WebForms, but here's a simple working HTTP handler tested with a 15 page 125KB test file that runs on my workstation:
<%# WebHandler Language="C#" Class="MergeFiles" %>
using System;
using System.Collections.Generic;
using System.Web;
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;
public class MergeFiles : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
List<byte[]> pdfs = new List<byte[]>();
var pdf = File.ReadAllBytes(context.Server.MapPath("~/app_data/test.pdf"));
for (int i = 0; i < 4000; ++i) pdfs.Add(pdf);
var Response = context.Response;
Response.ContentType = "application/pdf";
Response.AddHeader(
"content-disposition",
"attachment; filename=MergeLotsOfPdfs.pdf"
);
Response.BinaryWrite(MergeLotsOfPdfs(pdfs));
}
byte[] MergeLotsOfPdfs(List<byte[]> pdfs)
{
using (var ms = new MemoryStream())
{
using (Document document = new Document())
{
using (PdfCopy copy = new PdfCopy(document, ms))
{
document.Open();
for (int i = 0; i < pdfs.Count; ++i)
{
using (PdfReader reader = new PdfReader(
new RandomAccessFileOrArray(pdfs[i]), null))
{
copy.AddDocument(reader);
copy.FreeReader(reader);
}
}
}
}
return ms.ToArray();
}
}
public bool IsReusable { get { return false; } }
}
Tried to make the output file similar to what you described in the question, but YMMV, depending on how large the individual PDFs you're dealing with are in size. Here's the test output from my run:

So after a lot of messing around, I realized that there just was no way around it. However, I did manage to find a work-around. Instead of returning byte array, I return a temp file path, which I then transmit and delete there after.
private string MergeLotsOfPDFs(List<byte[]> PDFs)
{
Document doc = new Document();
Guid uniqueId = Guid.NewGuid();
string tempFileName = Server.MapPath("~/__" + uniqueId.ToString() + ".pdf");
using (FileStream ms = new FileStream(tempFileName, FileMode.Create, FileAccess.Write, FileShare.Read))
{
PdfCopy copy = new PdfCopy(doc, ms);
doc.Open();
int i = 0;
foreach (byte[] PDF in PDFs)
{
i++;
// Create a reader
PdfReader reader = new PdfReader(new RandomAccessFileOrArray(PDF), null);
// Cycle through all the pages
for (int currentPageNumber = 1; currentPageNumber <= reader.NumberOfPages; ++currentPageNumber)
{
// Read a page
PdfImportedPage curPg = copy.GetImportedPage(reader, currentPageNumber);
// Add the page over to the rest of them
copy.AddPage(curPg);
// This is a lie, it still costs money, hue hue hue :)~
copy.FreeReader(reader);
}
reader.Close();
}
// Close the document
doc.Close();
// Close the document
copy.Close();
}
// Return temp file path
return tempFileName;
}
And here is how I send that data to the client.
// Send the merged PDF file to the user.
System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
response.ClearContent();
Response.ClearHeaders();
response.ContentType = "application/pdf";
response.AddHeader("Content-Disposition", "attachment; filename=1094C.pdf;");
response.WriteFile(tempFileName);
HttpContext.Current.Response.Flush(); // Sends all currently buffered output to the client.
DeleteFile(tempFileName); // Call right after flush but before close
HttpContext.Current.Response.SuppressContent = true; // Gets or sets a value indicating whether to send HTTP content to the client.
HttpContext.Current.ApplicationInstance.CompleteRequest(); // Causes ASP.NET to bypass all events and filtering in the HTTP pipeline chain of execution and directly execute the EndRequest event.
Lastly, here is a fancy DeleteFile method
private void DeleteFile(string fileName)
{
if (File.Exists(fileName))
{
try
{
File.Delete(fileName);
}
catch (Exception ex)
{
//Could not delete the file, wait and try again
try
{
System.GC.Collect();
System.GC.WaitForPendingFinalizers();
File.Delete(fileName);
}
catch
{
//Could not delete the file still
}
}
}
}

Sharepoint to ASP.net MVC file download

I am quite ashamed to ask this question but somehow I am missing something.
Scenario
There is a sharepoint instance
There is a document list in sharepoint with three files
I have a asp.net MVC Portal which connects with Sharepoint instance
In a view it shows the list of files (3 in my case)
When user clicks on the item, the file is to be downloaded.
Problem
The file is downloaded but when you try to open it, word says the file downloaded is corrupt.
I have googled it and tried every variation of code. Only variation that works is to save the file on server and then download it to the client which as you know is not feasible
this is my code
As mentioned above the Sharepoint login,authentication etc all works correctly
fileref is the sharepoint path of the file
len is retrieved from Sharepoint
//int len= int.Parse(oListItemDoc.FieldValues["File_x0020_Size"].ToString());
string filePath = fileRef;
ClientContext clientContext = new ClientContext(GetSharePointUrl());
clientContext = SharepointAuthorisation(clientContext);
if (!string.IsNullOrEmpty(filePath))
{
var cd = new System.Net.Mime.ContentDisposition
{
FileName = Path.GetFileName(fileRef),
// always prompt the user for downloading, set to true if you want
// the browser to try to show the file inline
Inline = true,
};
Response.AppendHeader("Content-Disposition", cd.ToString());
byte[] fileArr=DownloadFile(title, clientContext, filePath,len,extension, "");
//FileInformation fileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(clientContext, fileRef.ToString());
//byte[] arr = new byte[len];
//fileInfo.Stream.Read(arr, 0, arr.Length - 1);
//return arr;
Response.AppendHeader("Content-Disposition", cd.ToString());
//return new FileStreamResult(fileInfo.Stream, "application /octet-stream");// vnd.openxmlformats-officedocument.wordprocessingml.document");
return File(fileArr, "application/docx" , Path.GetFileName(fileRef));
}
else
{
return null;
}
public byte[] DownloadFile(string title, ClientContext clientContext, string fileRef, int len, string itemExtension, string folderName)// Renamed Function Name getdownload to DownloadFiles
{
if (itemExtension == ".pdf")
{
//string completePath = Path.Combine(Server.MapPath("~"), folderName);
//string PdfFile = completePath + "/" + "PDF";
////if (!Directory.Exists(PdfFile))
//{
// Directory.CreateDirectory(PdfFile);
//}
FileInformation fileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(clientContext, fileRef.ToString());
byte[] arr = new byte[len];
fileInfo.Stream.Read(arr, 0, arr.Length);
return arr;
}
else
{
FileInformation fileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(clientContext, fileRef.ToString());
byte[] arr = new byte[len];
fileInfo.Stream.Read(arr, 0, arr.Length);
return arr;
}
}
What am I missing?

Probably it occurs since file size is determined incorrectly. Try to remove any dependency to file size from DownloadFile method as demonstrated below:
public static byte[] DownloadFile(ClientContext ctx,string fileUrl)
{
var fileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(ctx, fileUrl);
using (var ms = new MemoryStream())
{
fileInfo.Stream.CopyTo(ms);
return ms.ToArray();
}
}

download zip files by use of reader in c#

I have been working on this application that enables user to log in into another website, and then download specified file from that server. So far I have succeeded in logging on the website and download the file. But everything ruins when it comes to zip files.
Is there any chunk of code that could be helpful in reading the .zip files byte by byte or by using stream reader?
I m using downloadfile() but its not returning the correct zip file.
I need a method by which I can read zip files. Can I do it by using ByteReader()
The code used to download zip file is
string filename = "13572_BranchInformationReport_2012-05-22.zip";
string filepath = "C:\\Documents and Settings\\user\\Desktop\\" + filename.ToString();
WebClient client = new WebClient();
string user = "abcd", pass = "password";
client.Credentials = new NetworkCredential(user, pass);
client.Encoding = System.Text.Encoding.UTF8;
try
{
client.DownloadFile("https://web.site/archive/13572_BranchInformationReport_2012-05-22.zip", filepath);
Response.Write("Success");
}
catch (Exception ue)
{
Response.Write(ue.Message);
}
Thanks in advance.

is there any chunk of code that could be helpful in reading the zip files bytes by bytes aur by using stream reader.
Absolutely not. StreamReader - and indeed any TextReader is for reading text content, not binary content. A zip file is not text - it's composed of bytes, not characters.
If you're reading binary content such as zip files, you should be using a Stream rather than a TextReader of any kind.
Note that WebClient.DownloadFile and WebClient.DownloadData can generally make things easier for downloading binary content.

Another simple way to downlaod zip file
<asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl="~/DOWNLOAD/Filename.zip">Click To Download</asp:HyperLink>
Another solution
private void DownloadFile()
{
string getPath = "DOWNLOAD/FileName.zip";
System.IO.Stream iStream = null;
byte[] buffer = new Byte[1024];
// Length of the file:
int length;
// Total bytes to read:
long dataToRead;
// Identify the file to download including its path.
string filepath = Server.MapPath(getPath);
// Identify the file name.
string filename = System.IO.Path.GetFileName(filepath);
try
{
// Open the file.
iStream = new System.IO.FileStream(filepath, System.IO.FileMode.Open,
System.IO.FileAccess.Read, System.IO.FileShare.Read);
// Total bytes to read:
dataToRead = iStream.Length;
// Page.Response.ContentType = "application/vnd.android.package-archive";
// Page.Response.ContentType = "application/octet-stream";
Page.Response.AddHeader("Content-Disposition", "attachment; filename=" + filename);
// Read the bytes.
while (dataToRead > 0)
{
// Verify that the client is connected.
if (Response.IsClientConnected)
{
// Read the data in buffer.
length = iStream.Read(buffer, 0, 1024);
// Write the data to the current output stream.
Page.Response.OutputStream.Write(buffer, 0, length);
// Flush the data to the HTML output.
Page.Response.Flush();
// buffer = new Byte[1024];
dataToRead = dataToRead - length;
}
else
{
//prevent infinite loop if user disconnects
dataToRead = -1;
}
}
}
catch (Exception ex)
{
// Trap the error, if any.
Page.Response.Write(ex.Message);
}
finally
{
if (iStream != null)
{
//Close the file.
iStream.Close();
Page.Response.Close();
}
}
}

Your answer
WebRequest objRequest = System.Net.HttpWebRequest.Create(url);
objResponse = objRequest.GetResponse();
byte[] buffer = new byte[32768];
using (Stream input = objResponse.GetResponseStream())
{
using (FileStream output = new FileStream ("test.doc",
FileMode.CreateNew))
{
int bytesRead;
while ( (bytesRead=input.Read (buffer, 0, buffer.Length)) > 0)
{
output.Write(buffer, 0, bytesRead);
}
}
}
This is how i achieved it. Thanks everyone for ur help