Develop Reference

c#- Corrupt file when writing to Response

I am trying to write a file to the output response stream using ASP.Net. When I download the file, I get a Errors were found opening .zip file. You can extract files from this archive, but other programs may not be able to open it. Do you want to try fixing the problems? error. I am however able to cancel this and open the zip file correctly.
What could I be doing wrong?
ASP.Net\C# code:
var pathToFile = "c:\abc.zip";
string fileName = Path.GetFileName(pathToFile);
byte[] buffer;
using (var fileStream = new FileStream(pathToFile, Filemode.open))
{
buffer = new byte[fileStream. Length];
fileStream.Read(buffer, 0, (int)fileStream.Length);
}
Response.Clear();
Response.Buffer = true;
Response.AppendHeader("content-disposition", string.Format(#"attachment; filename={0}.zip", filename));
Response.ContentType = "application/zip";
Response.AppendHeader("content-length", buffer.Length.ToString());
Response.WriteFile(pathToFile);

If you want to use buffer and write file to user, do not use Response.WriteFile.
Change to Response.OutputStream.Write, and modify your codes, like this:
var pathToFile = "c:\abc.zip";
string fileName = Path.GetFileName(pathToFile);
byte[] buffer = new byte[0];
using (var fileStream = new FileStream(pathToFile, FileMode.Open, FileAccess.Read))
{
buffer = new byte[fileStream.Length];
fileStream.Read(buffer, 0, buffer.Length);
}
Response.Clear();
Response.AppendHeader("content-disposition", string.Format(#"attachment; filename={0}", filename));
Response.ContentType = "application/zip";
Response.OutputStream.Write(buffer, 0, buffer.Length);
Response.Flush();
Response.End();

How do I download a file using to the downloads folder with response.WriteResponseStreamToFile? (Amazon S3, C#)

I have some PDFs stored in S3 and I'm trying to make a link that will download them. This is the method that I have so far:
public virtual ActionResult DownloadPDF(string filename)
{
string secretKey = this.UnitOfWork.ApplicationSettingRepository.GetOrCreateByName<string>("StorageProvider_AmazonS3_SecretKey");
string accessKey = this.UnitOfWork.ApplicationSettingRepository.GetOrCreateByName<string>("StorageProvider_AmazonS3_AccessKey");
var bucket = this.UnitOfWork.ApplicationSettingRepository.GetOrCreateByName<string>("StorageProvider_AmazonS3_BucketName");
var serviceUrl = this.UnitOfWork.ApplicationSettingRepository.GetOrCreateByName<string>("StorageProvider_AmazonS3_ServiceUrl");
AmazonS3Config config = new AmazonS3Config();
config.ServiceURL = serviceUrl;
var client = Amazon.AWSClientFactory.CreateAmazonS3Client(
accessKey,
secretKey,
config
);
GetObjectRequest request = new GetObjectRequest();
request.BucketName = bucket;
request.Key = "userfiles/MSD IMAGES/ProductDocumentation/" + filename;
GetObjectResponse response = client.GetObject(request);
response.WriteResponseStreamToFile("\\Downloads\\" + filename);
}
I got that method from this documentation here but I want to download the download to show in the browser, and go to the standard downloads folder. I created this method previously for downloading csv files:
var csv = new StringBuilder();
csv.AppendLine("col1,col2,col3");
var bytes = Encoding.UTF8.GetBytes(csv.ToString());
var response = new FileContentResult(bytes, "text/csv");
response.FileDownloadName = fileName;
return response;
I tried doing the same thing with the S3 file:
GetObjectResponse response = client.GetObject(request);
// response.WriteResponseStreamToFile("\\Downloads\\" + filename);
var bytes = Encoding.UTF8.GetBytes(response.ToString());
var download = new FileContentResult(bytes, "application/pdf");
download.FileDownloadName = filename;
return download;
it downloads a file, but the pdf doesn't work (it fails to load). How do I download the file that I got from S3?

Here's the working solution I came up with:
GetObjectResponse response = client.GetObject(request);
using (Stream responseStream = response.ResponseStream)
{
var bytes = ReadStream(responseStream);
var download = new FileContentResult(bytes, "application/pdf");
download.FileDownloadName = filename;
return download;
}
public static byte[] ReadStream(Stream responseStream)
{
byte[] buffer = new byte[16 * 1024];
using (MemoryStream ms = new MemoryStream())
{
int read;
while ((read = responseStream.Read(buffer, 0, buffer.Length)) > 0)
{
ms.Write(buffer, 0, read);
}
return ms.ToArray();
}
}

you would need to do something like the following
int byteCount
byte[] buffer = new byte[2048]; // read in chunks of 2KB
Stream responseStream= Response.GetResponseStream();
Response.ContentType = "application/pdf";
Response.AddHeader("Content-Disposition", "attachment;filename=" + filename);
while ((byteCount = responseStream.Read(buffer, 0, buffer.Length)) > 0)
{
Response.OutputStream.Write(buffer, 0, byteCount);
}
Response.Flush();
Response.Close();
Response.End();

Access to the path is denied - different from user

I have a web page in ASP.Net & C#. This page show a table with our orders. Then the suppliers need to check data and save them.
My problem : When suppliers click on "Save", a PDF is downloaded. We have more than 100 suppliers who use this website, it works for 98% of our suppliers. But 3 suppliers have an error message when they click on "save" :
Access to the path "C:\ExterneData\PDF\F000001.pdf" is denied.
This is the code used to access the PDF :
// Save the document...
string filename = Server.MapPath("~/PDF/" + Url_SupplierId + ".pdf");
document.Save(filename);
string path = filename;
string name = Url_SupplierId + ".pdf";
FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
// Create a byte array of file stream length
byte[] _downFile = new byte[fs.Length];
//Read block of bytes from stream into the byte array
fs.Read(_downFile, 0, System.Convert.ToInt32(fs.Length));
//Close the File Stream
fs.Close();
Session["PDFControl"] = _downFile;
Session["PDFControlName"] = Url_SupplierId + "_" + Url_PurchId + ".pdf";
if (File.Exists(filename))
File.Delete(filename);
byte[] _downFile2 = Session["PDFControl"] as byte[];
Session["PDFControl"] = null;
Response.Clear();
Response.ClearContent();
Response.ClearHeaders();
Response.ContentType = "application/pdf";
Response.AddHeader("Content-Disposition", "attachment; filename=" + Session["PDFControlName"] + "; size=" + _downFile2.Length.ToString());
Response.BinaryWrite(_downFile2);
Response.Flush();
Response.End();
The thing I don't understand is this message show me some access right error. But it works for me and 98% of our suppliers. So the error doesn't come from the server ?

If you've got all the permissions correct, then the only think I can think of is to try it a different way (do these suppliers have bigger PDFs than the others?). I don't see the need to create 2 byte arrays or use session variables here. Maybe something like this:
// Save the document...
string filename = Server.MapPath("~/PDF/" + Url_SupplierId + ".pdf");
document.Save(filename);
using (FileStream fs = new FileStream(filename, FileMode.Open, FileAccess.Read))
{
// Create a byte array of file stream length
byte[] _downFile = new byte[fs.Length];
int numBytesToRead = (int)fs.Length;
int numBytesRead = 0;
//Read block of bytes from stream into the byte array
while (numBytesToRead > 0)
{
// Read may return anything from 0 to numBytesToRead.
int n = fs.Read(_downFile, numBytesRead, numBytesToRead);
// Break when the end of the file is reached.
if (n == 0)
break;
numBytesRead += n;
numBytesToRead -= n;
}
numBytesToRead = _downFile.Length;
}
if (File.Exists(filename))
File.Delete(filename);
Response.Clear();
Response.ClearContent();
Response.ClearHeaders();
Response.ContentType = "application/pdf";
Response.AddHeader("Content-Disposition", "attachment; filename=" + Path.GetFileName(filename) + "; size=" + numBytesToRead);
Response.BinaryWrite(_downFile);
Response.Flush();
Response.End();

sending httpresponses in library file c#

i used the following code to download the file folder in asp.net website are
string path = #"E:\sample.zip";
FileInfo file = new FileInfo(path);
int len = (int)file.Length, bytes;
Response.ContentType = "text/html";
// Response.AddHeader "Content-Disposition", "attachment;filename=" + filename;
Response.AppendHeader("content-length", len.ToString());
byte[] buffer = new byte[1024];
using(Stream stream = File.OpenRead(path)) {
while (len > 0 && (bytes =
stream.Read(buffer, 0, buffer.Length)) > 0)
{
Response.OutputStream.Write(buffer, 0, bytes);
len -= bytes;
}
}
it works fine/...
but my problem is when i used the same code to the library file as
FileInfo file = new FileInfo(ZipPath);
int len = (int)file.Length, bytes;
HttpResponse Response = new HttpResponse(TextWriter.Null);
Response.ContentType = "text/html";
Response.AppendHeader("content-length", len.ToString());
byte[] buffer = new byte[1024];
using (Stream stream = File.OpenRead(ZipPath))
{
while (len > 0 && (bytes =
stream.Read(buffer, 0, buffer.Length)) > 0)
{
Response.OutputStream.Write(buffer, 0, bytes);
len -= bytes;
}
}
}
it throws me a error as
OutputStream is not available when a custom TextWriter is used.
i guess the problem is in that line
HttpResponse Response = new HttpResponse(TextWriter.Null);
can you provide me a solution
waiting for your responses....

You can try with this code
TextWriter sw = new StringWriter();
HttpResponse Response = new HttpResponse(sw);

i replaced the structures as
HttpResponse response = HttpContext.Current.Response;
it works fine.....
Thanks all for your support

memorystream contains bad xml markup when read

What is my issue here? When I write the stream back out to web, open the file it contains some of the content but all malformed and some missing.
Am I experiencing loss of data due to a logic error?
Note: the readstream and writestream below mocks up what a service will be filling in. I will be receiving a stream to read from the service. I'll need to write that stream back out.
MemoryStream writeStream = new MemoryStream();
byte[] buffer = new byte[256];
OrderDocument doc = new OrderDocument();
doc.Format = "xml";
doc.DocumentId = "5555555";
doc.Aid = "ZZ";
doc.PrimaryServerPort = "PORT";
MemoryStream readStream = new MemoryStream(doc.GetDocument());
while (readStream != null && readStream.Read(buffer, 0, buffer.Length) > 0)
{
writeStream.Write(buffer, 0, buffer.Length);
}
writeStream.Flush();
writeStream.Position = 0;
Response.Buffer = true;
Response.Clear();
Response.ClearContent();
Response.ClearHeaders();
Response.ContentType = "text/xml";
Response.ClearHeaders();
Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xml", doc.DocumentId));
Response.AddHeader("Content-Length", writeStream.Length.ToString());
Response.BinaryWrite(writeStream.ToArray());
Response.End();

Am I experiencing loss of data due to a logic error?
Yes probably, you may try simplifying your code a little bit. I don't really see the need of multiple memory streams here:
OrderDocument doc = new OrderDocument();
doc.Format = "xml";
doc.DocumentId = "5555555";
doc.Aid = "ZZ";
doc.PrimaryServerPort = "PORT";
byte[] buffer = doc.GetDocument();
Response.Buffer = true;
Response.Clear();
Response.ClearHeaders();
Response.ContentType = "text/xml";
Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xml", doc.DocumentId));
Response.OutputStream.Write(buffer, 0, buffer.Length);