Thread was being aborted using TransmitFile - c#

There are a ton of threads Stackoverflow about this error, but none of them seem to help me solve my problem.
I'm transferring a small Excel file from server to client. My code:
protected void SaveSpreadsheet(string filePath)
{
FileInfo myfile = new FileInfo(filePath);
if (myfile.Exists)
{
Response.ClearContent();
Response.AddHeader("Content-Disposition", "attachment; filename=" + myfile.Name);
Response.AddHeader("Content-Length", myfile.Length.ToString());
Response.ContentType = "xlsx";
Response.TransmitFile(myfile.FullName);
Response.End();
// Delete the file from the server
if (File.Exists(strSaveFilePath))
{
File.Delete(strSaveFilePath);
}
}
}
I'm getting the 'Thread was being aborted' error. I know from troubleshooting that the Response.End(); line is the problem.
A lot of the problems associated with this error are from people using Response.Redirect, but those solutions don't seem work for me. According to Microsoft, replacing that line with HttpContext.Current.ApplicationInstance.CompleteRequest was their solution, but that gives me another error.
Many of the solutions on this and other sites recommend moving this code outside my Try-Catch block. I tried that, but the last part of my code (deleting the file) does not work, so I know I'm still getting an error.
Can anyone help me solve this problem? Thanks.

Related

I can't send a file from my server filesystem to the client (downloading with the Save As dialog box)

I am working with some calculations and the product of my business logic is the creation of a PDF report (C# ASP.NET). So far, I have managed to create the report. The convention of my company is storing all the data in .gz format somewhere in the filesystem. At the click of some button, I need to send the file to the client, with the opening of the dialog box for downloading and saving the file to the desired destination.
I have tried a lot of options, including .TransmitFile, .OutputStream.Write as they are the methods that the Response object has. However, I'm not getting any feedback back. There doesn't seem to be any errors and the code is running as the methods never happened. If I set a try catch block, the code runs into an exception with description "Thread was aborted", though I heard that Response.End always throws an exception.
var file = new FileInfo(integrityCheckInfo.ReportPath);
var buffer = integrityCheckInfo.ReportData;
//Code for downloading the report, doesn't work, and I don't know how to fix this.
if (File.Exists(integrityCheckInfo.ReportPath))
{
Response.Clear();
//Response.AddHeader("Accept-encoding", "gzip, deflate");
Response.AddHeader("content-length", buffer.Length.ToString());
Response.ContentType = "application/x-gzip";
Response.Buffer = true;
Response.Expires = -1000;
Response.AddHeader("content-disposition", "attachment; filename=report.gz");
//Response.BinaryWrite(buffer);
Response.OutputStream.Write(buffer, 0, buffer.Length);
//Response.Flush();
//Response.TransmitFile(integrityCheckInfo.ReportPath);
//Response.Flush();
Response.End();
}
The code that starts with // are comments and they are not included in this iteration where I wanted to download the .gz instead of the PDF but also got nothing for feedback.

End of result from BinaryWrite Flush is missing

I'm having some problems dealing with downloading a file from the server.
The problem is that the end of the downloaded file is missing.
I have found some indications of other people having similar problems, but nothing that helps me in my problem.
When debugging I have learned that the length of fileData is correct, and all data is present in the byte array when calling BinaryWrite.
That leaves the BinaryWrite, Flush or Close calls...
I have read about not using Response.End or Response.Close, for example here:
HttpResponse.End vs HttpResponse.Close vs HttpResponse.SuppressContent and it seems like a probable cause, but what should I use instead (have tried to remove Response.Close completely, but that result in too much data output)?
Someone knows what might cause this behaviour, and how to fix it?
EDIT: Just tried with Response.ContentType = "binary/octet-stream"; and it works like a charm!
What is the difference between text/plain and binary/octet-stream that may cause a behavior like this?
It even works without the Close call...
MORE EDIT: Seems like compression of Responses was activated on the server-side. Apparently there seems to be an issue with plain text streams when compression is active.
The code I have is:
private void DownloadFile(byte[] fileData, string fileName, string fileExtension)
{
Response.Clear();
Response.AddHeader("content-disposition", "attachment; filename=" + fileName + fileExtension);
Response.AddHeader("Content-Length", fileData.Length.ToString(CultureInfo.InvariantCulture));
Response.ContentType = "text/plain";
Response.BinaryWrite(fileData);
Response.Flush();
Response.Close();
}
If compression is active on the server-side (IIS) it apparently causes trouble with text/plain streams.
For you with similar problems, try deactivating, it might help!
It surely did for me!

ASP Force download txt file sending back source instead

I have a function in ASP that returns a TXT file.
I want the user to download the file but the browser wanted to keep displaying it when I did Response.Redirect("/Dir/Dir/TextFilePath.txt");
So I discovered that if you add this to the header it forces a download
Response.AddHeader("content-disposition",
"attachment;filename=/Dir/Dir/TextFilePath.txt");
And this DOES force download the file, with one catch.
The file is the aspx source code and not my txt file.... It's named correctly but it is most definitely not the txt file.
here is a correct way to download files in asp.net.
note the 'a correct way' and not 'the correct way', you can do it in other ways but this one works for me.
try
{
Response.Clear();
Response.ClearHeaders();
Response.ClearContent();
Response.AddHeader("content-disposition", "attachment; filename=" + _Filename);
Response.AddHeader("Content-Type", "application/Word");
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Length", _FileLength_in_bytes);
Response.BinaryWrite(_Filedata_bytes);
Response.End();
}
catch (ThreadAbortException)
{ }
finally
{
}
the example above transmits a word file by sending it as a byte array.
you dont have to do it this way, but it works.
also i would like to add for anyone who decides to use my method,
this WILL throw a ThreadAbortException at Response.End().
its a known issue and it affects nothing, everything is being executed correctly but the exception is still thrown, so it must be caught.
You can't affect the headers of the URL supplied for the redirect from the page where the redirect was issued from. I suspect that you actually want to do something like:
var responseText =
File.ReadAllText(Server.MapPath("~/Dir/Dir/TextFilePath.txt"));
Response.ContentType="text/plain";
Response.AddHeader("content-disposition",
"attachment;filename=TextFilePath.txt");
Response.Output.Write(responseText);
Response.End();
Have you tried something like this?
this.Response.AddHeader("content-disposition", "attachment;filename=" + file);
Response.TransmitFile( Server.MapPath(fileName) );
Response.End();

.net CSV file stream to browser loosing characters on production server

I've got basic functionality to stream a file to the browser which invokes a "Save As". The output is dynamically generated and stored within a string and not a file saved on the server.
See code below.
string output = GenerateCSVDdata;
Response.Clear();
Response.ClearHeaders();
Response.AddHeader("Content-Disposition", "attachment; filename=\"test.csv\");
Response.ContentType = "application/octet-stream";
Response.BinaryWrite(System.Text.Encoding.UTF8.GetPreamble());
Response.Write(output);
Response.End();
Now, on my development server, the CSV fully downloads. On the production server, the last few characters on end are cut off. The larger the CSV, the more characters are missing. I've tried so many different things like Response.Flush etc but nothing can fix it. The only thing I can do is throw a load of empty chars on the end in hope nothing gets cut.
Is there something quite wrong with this method of streaming a file download without actually saving the file to disk?
Thanks for your help.
Can you determine if there is a difference in the byte count for the .csv file you are using?
byte[] defaultEncodingBytes = System.Text.Encoding.Default.GetBytes(defaultEncodingFileContents);
byte[] UTF8EncodingBytes = System.Text.Encoding.UTF8.GetBytes(defaultEncodingFileContents);
Try this, it worked for me.
void DownloadFile(string filename)
{
//string filename = "c:\\temp\\test.csv";
byte[] contents = System.IO.File.ReadAllBytes(filename);
Response.Clear();
Response.ClearHeaders();
Response.AppendHeader("Content-disposition", String.Format("attachment; filename=\"{0}\"", System.IO.Path.GetFileName(filename)));
Response.AppendHeader("Content-Type", "binary/octet-stream");
Response.AppendHeader("Content-length", contents.Length.ToString());
Response.BinaryWrite(contents);
if (Response.IsClientConnected)
Response.Flush();
}
Regards.

ZIP download contains html content

When I use the following code to download a ZIP file it appears to work. However, when I attempt to open the downloaded ZIP, I get an 'invalid compressed folder' message. When I open the ZIP in notepad I see it is filled with HTML.
string fp = Server.MapPath("directory\\file.zip");
FileInfo file = new FileInfo(fp);
if (file.Exists)
{
Response.ClearContent();
Response.AddHeader("content-disposition","attachment; filename=" + file.Name);
Response.AddHeader("content-length", file.Length.ToString());
Response.ContentType = "application/zip";
Response.TransmitFile(file.FullName);
Response.End();
}
An issue I can't seem to fix that is probably related is when I try to manually type in the address of the file (http://website.com/downloads/file.zip), I get a redirect (http://website.com/login.aspx) even when logged in as the admin. Any pointers in where to look would be greatly appreciated.
Instead of just using Response.ClearContent() also use Response.ClearHeaders() to remove all the current headers as well as the body of the response.
From MSDN, HttpResponse.ClearContent Method:
The ClearContent method does not clear header information.

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