Develop Reference

C# Download big file from Server with less memory consumption

I have a big file of memory size 42 mb. I want to download the file with less memory consumption.
Controller Code
public ActionResult Download()
{
var filePath = "file path in server";
FileInfo file = new FileInfo(filePath);
Response.ContentType = "application/zip";
Response.AppendHeader("Content-Disposition", "attachment; filename=folder.zip");
Response.TransmitFile(file.FullName);
Response.End();
}
alernative method tried with Stream
public ActionResult Download()
{
string failure = string.Empty;
Stream stream = null;
int bytesToRead = 10000;
long LengthToRead;
try
{
var path = "file path from server";
FileWebRequest fileRequest = (FileWebRequest)FileWebRequest.Create(path);
FileWebResponse fileResponse = (FileWebResponse)fileRequest.GetResponse();
if (fileRequest.ContentLength > 0)
fileResponse.ContentLength = fileRequest.ContentLength;
//Get the Stream returned from the response
stream = fileResponse.GetResponseStream();
LengthToRead = stream.Length;
//Indicate the type of data being sent
Response.ContentType = "application/octet-stream";
//Name the file
Response.AddHeader("Content-Disposition", "attachment; filename=SolutionWizardDesktopClient.zip");
Response.AddHeader("Content-Length", fileResponse.ContentLength.ToString());
int length;
do
{
// Verify that the client is connected.
if (Response.IsClientConnected)
{
byte[] buffer = new Byte[bytesToRead];
// Read data into the buffer.
length = stream.Read(buffer, 0, bytesToRead);
// and write it out to the response's output stream
Response.OutputStream.Write(buffer, 0, length);
// Flush the data
Response.Flush();
//Clear the buffer
LengthToRead = LengthToRead - length;
}
else
{
// cancel the download if client has disconnected
LengthToRead = -1;
}
} while (LengthToRead > 0); //Repeat until no data is read
}
finally
{
if (stream != null)
{
//Close the input stream
stream.Close();
}
Response.End();
Response.Close();
}
return View("Failed");
}
due to size of the file, it is consumpting more memory which leads to performance issue.
After checking in iis log, the download process is taking 42 mb and 64 mb each respectively.
Thanks in advance

A better option would be to use FileResult instead of ActionResult:
Using this method means you don't have to load the file/bytes in memory before serving.
public FileResult Download()
{
var filePath = "file path in server";
return new FilePathResult(Server.MapPath(filePath), "application/zip");
}
Edit: For larger files FilePathResult will also fail.
Your best bet is probably Response.TransmitFile() then. I've used this on larger files (GBs) and had no issues before
public ActionResult Download()
{
var filePath = #"file path from server";
Response.Clear();
Response.ContentType = "application/octet-stream";
Response.AppendHeader("Content-Disposition", "filename=" + filePath);
Response.TransmitFile(filePath);
Response.End();
return Index();
}
From MSDN:
Writes the specified file directly to an HTTP response output stream,
without buffering it in memory.

Try setting the Transfer-Encoding header to chunked, and return an HttpResponseMessage with a PushStreamContent. Transfer-Encoding of chunked means that the HTTP response will not have a Content-Length header, and so the client will have to parse the chunks of the HTTP response as a stream. Note, I've never run across a client (browser, etc) that didn't handle Transfer Encoding chunked. You can read more at the link below.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Transfer-Encoding
[HttpGet]
public async Task<HttpResponseMessage> Download(CancellationToken token)
{
var response = new HttpResponseMessage(System.Net.HttpStatusCode.OK)
{
Content = new PushStreamContent(async (stream, context, transportContext) =>
{
try
{
using (var fileStream = System.IO.File.OpenRead("some path to MyBigDownload.zip"))
{
await fileStream.CopyToAsync(stream);
}
}
finally
{
stream.Close();
}
}, "application/octet-stream"),
};
response.Headers.TransferEncodingChunked = true;
response.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment")
{
FileName = "MyBigDownload.zip"
};
return response;
}

I had similar problem but I didn't have file on local disk, I had to download it from API (my MVC was like a proxy).
The key thing is to set Response.Buffer=false; on your MVC Action. I think #JanusPienaar's first solution should work with this.
My MVC action is:
public class HomeController : Controller
{
public async Task<FileStreamResult> Streaming(long RecordCount)
{
HttpClient Client;
System.IO.Stream Stream;
//This is the key thing
Response.Buffer=false;
Client = new HttpClient() { BaseAddress=new Uri("http://MyApi", };
Stream = await Client.GetStreamAsync("api/Streaming?RecordCount="+RecordCount);
return new FileStreamResult(Stream, "text/csv");
}
}
And my test WebApi (which generates the file) is:
public class StreamingController : ApiController
{
// GET: api/Streaming/5
public HttpResponseMessage Get(long RecordCount)
{
var response = Request.CreateResponse();
response.Content=new PushStreamContent((stream, http, transport) =>
{
RecordsGenerator Generator = new RecordsGenerator();
long i;
using(var writer = new System.IO.StreamWriter(stream, System.Text.Encoding.UTF8))
{
for(i=0; i<RecordCount; i++)
{
writer.Write(Generator.GetRecordString(i));
if(0==(i&0xFFFFF))
System.Diagnostics.Debug.WriteLine($"Record no: {i:N0}");
}
}
});
return response;
}
class RecordsGenerator
{
const string abc = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
char[] Chars = new char[14];//Ceiling(log26(2^63))
public string GetRecordString(long Record)
{
int iLength = 0;
long Div = Record, Mod;
do
{
iLength++;
Div=Math.DivRem(Div, abc.Length, out Mod);
//Save from backwards
Chars[Chars.Length-iLength]=abc[(int)Mod];
}
while(Div!=0);
return $"{Record} {new string(Chars, Chars.Length-iLength, iLength)}\r\n";
}
}
}
}
If RecordCount is 100000000, the file generated by TestApi is 1.56 GB. Neither WebApi nor MVC consumes so much memory.

There is the Rizwan Ansari post that worked for me:
There are situation when you need to provide download option for a big file located somewhere on server or generated at runtime. Below function could be used to download files of any size. Sometimes downloading big file throws exception OutOfMemoryException showing “Insufficient memory to continue execution of the program”. So this function also handle this situation by breaking down file in 1 MB chunks (can be customized by changing bufferSize variable).
Usage:
DownloadLargeFile("A big file.pdf", "D:\\Big Files\\Big File.pdf", "application/pdf", System.Web.HttpContext.Current.Response);
You can change "application/pdf" by the right Mime type
Download Function:
public static void DownloadLargeFile(string DownloadFileName, string FilePath, string ContentType, HttpResponse response)
{
Stream stream = null;
// read buffer in 1 MB chunks
// change this if you want a different buffer size
int bufferSize = 1048576;
byte[] buffer = new Byte[bufferSize];
// buffer read length
int length;
// Total length of file
long lengthToRead;
try
{
// Open the file in read only mode
stream = new FileStream(FilePath, FileMode.Open, FileAccess.Read, FileShare.Read);
// Total length of file
lengthToRead = stream.Length;
response.ContentType = ContentType;
response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(DownloadFileName, System.Text.Encoding.UTF8));
while (lengthToRead > 0)
{
// Verify that the client is connected.
if (response.IsClientConnected)
{
// Read the data in buffer
length = stream.Read(buffer, 0, bufferSize);
// Write the data to output stream.
response.OutputStream.Write(buffer, 0, length);
// Flush the data
response.Flush();
//buffer = new Byte[10000];
lengthToRead = lengthToRead - length;
}
else
{
// if user disconnects stop the loop
lengthToRead = -1;
}
}
}
catch (Exception exp)
{
// handle exception
response.ContentType = "text/html";
response.Write("Error : " + exp.Message);
}
finally
{
if (stream != null)
{
stream.Close();
}
response.End();
response.Close();
}
}

you just have to Using IIS to Enable HTTP Downloads look at this link
and you just need to return the HTTP path of the file it will be download so fast and so easy.

Network error downloading files on OSX

I have a site with a list of photos. The user has the option to download each of the photos. The download just writes the result to the output stream.
Here's the code:
[WebMethod]
public static void DownloadPhotoAsset(string assetId)
{
var photoAsset = GetPhotoAsset(assetId);
Stream stream = null;
int bytesToRead = 10000;
byte[] buffer = new Byte[bytesToRead];
try
{
HttpWebRequest fileReq =
(HttpWebRequest)HttpWebRequest.Create(photoAsset.FileAbsoluteUrl);
HttpWebResponse fileResp = (HttpWebResponse)fileReq.GetResponse();
if (fileReq.ContentLength > 0)
fileResp.ContentLength = fileReq.ContentLength;
stream = fileResp.GetResponseStream();
var resp = HttpContext.Current.Response;
resp.ContentType = "application/octet-stream";
resp.AddHeader("Content-Disposition",
"attachment; filename=\"" +
Path.GetFileName(photoAsset.FileAbsoluteUrl) + "\"");
resp.AddHeader("Content-Length", fileResp.ContentLength.ToString());
int length;
do
{
// verify that the client is connected.
if (resp.IsClientConnected)
{
// read data into the buffer and write it out
// to the response's output stream
length = stream.Read(buffer, 0, bytesToRead);
resp.OutputStream.Write(buffer, 0, length);
// flush the data and clear the buffer
resp.Flush();
buffer = new Byte[bytesToRead];
}
else
length = -1; // cancel the download if client has disconnected
} while (length > 0); //Repeat until no data is read
}
finally
{
if (stream != null)
stream.Close(); // close the input stream
}
}
This works fine in every browser on Windows, but I get network connection issues on Macs.
In Safari, the download stops after a second and says "The network connection was lost"
In Chrome, the error says "Failed - Network Error"
In Firefox, the error says "Download Error - image.jpeg.part could not be saved, because the source file could not be read"
I've checked on two different Macs with OSX 10.7.4 and and OSX 10.8.3
Anyone know what I'm doing wrong here?

Download file ASP.NET C#

I am trying to download a file to any location on my computer, but it is sending it right to my downloads folder when I click the button. The code I am using is below:
I want to be able to chose "Desktop, My Documents, ETC". What am I doing wrong?
protected void Button1_Click(object sender, EventArgs e)
{
// The file path to download.
string filepath = #"C:\Test\Test.docx";
// The filename used to save the file to the client's system..
string filename = Path.GetFileName( filepath );
Stream stream = null;
try
{
// Open the file into a stream.
stream = new FileStream(filepath, FileMode.Open, FileAccess.Read, FileShare.Read );
// Total bytes to read:
long bytesToRead = stream.Length;
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment; filename=" + filename );
// Read the bytes from the stream in small portions.
while ( bytesToRead > 0 )
{
// Make sure the client is still connected.
if (Response.IsClientConnected)
{
// Read the data into the buffer and write into the
// output stream.
byte[] buffer = new Byte[10000];
int length = stream.Read(buffer, 0, 10000);
Response.OutputStream.Write(buffer, 0, length);
Response.Flush();
// We have already read some bytes.. need to read
// only the remaining.
bytesToRead = bytesToRead - length;
}
else
{
// Get out of the loop, if user is not connected anymore..
bytesToRead = -1;
}
}
}
catch(Exception ex)
{
Response.Write(ex.Message);
// An error occurred..
}
finally
{
if ( stream != null ) {
stream.Close();
}
}
}

This have to do with your browser settings - What browser do you use ? What ever, go to the settings of your browser, locate the download options, and tell them to ask you where to save it first.
For google chrome: Change download locations
For Firefox: Change what Firefox does when you click on or download a file

File upload through WCF Stream, Images not visible

Can anyone help with a small problem I am having, I have WCF Rest Based Service, which has function that can accept a stream, this will be used for uplaoding images/audio/video to the server and then storing them on the server somewhere.
Testing with and image, and it appears to work, i select the image in the client, and a few seconds later the image appears on the server in the location expected, but when i try to open the image in windows picture viewer (or any image viewer), i get "No Preview Available", and no image to view.
I am assuming it is because i am not recreating the file again correctly from the stream.
This is the method on the WCF Rest Service
public void PutFileInFolder(int eid, Stream fileContents)
{
try
{
byte[] buffer = new byte[32768];
MemoryStream ms = new MemoryStream();
int bytesRead = 0;
int totalBytesRead = 0;
do
{
bytesRead = fileContents.Read(buffer, 0, buffer.Length);
totalBytesRead += bytesRead;
ms.Write(buffer, 0, bytesRead);
} while (bytesRead > 0);
//now have file in memorystream
//save the file to the users folder
FileStream file = new FileStream(#"C:\bd_sites\ttgme\wwwroot\Evidence\{" + ed.LearnerID + #"}\" + ed.EvidenceFileName, FileMode.Create, System.IO.FileAccess.Write);
byte[] bytes = new byte[ms.Length];
ms.Read(bytes, 0, (int)ms.Length);
file.Write(bytes, 0, bytes.Length);
file.Close();
ms.Close();
}
catch (Exception ex)
{
return;
}
}
And this is the client function for sending the file/image
private void PostFile(EvidenceObject eo)
{
try
{
// Create the REST request.
string url = ConfigurationManager.AppSettings["serviceUrl"];
string requestUrl = string.Format("{0}/PutFileInFolder/{0}", 1001);
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(requestUrl);
request.Method = "POST";
request.ContentType = "text/plain";
byte[] fileToSend = File.ReadAllBytes(txtFileName.Text);
request.ContentLength = fileToSend.Length;
using (Stream requestStream = request.GetRequestStream())
{
// Send the file as body request.
requestStream.Write(fileToSend, 0, fileToSend.Length);
requestStream.Close();
}
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
Console.WriteLine("HTTP/{0} {1} {2}", response.ProtocolVersion, (int)response.StatusCode, response.StatusDescription);
MessageBox.Show("File sucessfully uploaded.", "Upload", MessageBoxButton.OK, MessageBoxImage.Information);
this.DialogResult = true;
}
catch (Exception ex)
{
MessageBox.Show("Error during file upload: " + ex.Message, "Upload", MessageBoxButton.OK, MessageBoxImage.Error);
}
}
Also just tested a video file, the orignal file plays happily, then when i upload it through the service, the file that is created on the server wont play.
I am sure it is somemthing really dumb i am doing, but any help is really appreciated.

The problem was the way i was writing to the file stream, i wasnt actually passing out the bytes of the file, but rather the new bytes making the file the same size but with basically no contents of the original file.
this was the change to the code
//FileStream file = new FileStream(#"C:\bd_sites\ttgme\wwwroot\Evidence\{" + ed.LearnerID + #"}\" + ed.EvidenceFileName, FileMode.Create, System.IO.FileAccess.Write);
//byte[] bytes = new byte[ms.Length];
////ms.Read(buffer, 0, (int)ms.Length);
//file.Write(bytes, 0, bytes.Length);
//file.Close();
//ms.Close();
using (FileStream fs = File.OpenWrite(#"C:\bd_sites\ttgme\wwwroot\Evidence\{" + ed.LearnerID + #"}\" + ed.EvidenceFileName))
{
ms.WriteTo(fs);
fs.Close();
ms.Close();
}

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