How to Avoid Response.End() "Thread was being aborted" Exception during the Excel file download

Question

I tried to convert my dataset into excel and download that excel .I got my required excel file.But System.Threading.ThreadAbortException was raised every excel download. How to resolve this issue ?.. Please help me...

I call this method in my aspx screen.There also same exception has thrown by this method.

I call that public void ExportDataSet(DataSet ds) function in many aspx screens and also I am maintaining error logger method for exceptions which are raised at runtime right those exceptions are write into a .txt files. So that same exception is logged in all the aspx screen's txt files.I just want to avoid this exception throws from method declared class file to aspx. Simply i just want to handle this exception at my method declaration class file itself.

ASPX File Method call: excel.ExportDataSet(dsExcel);

Method Definition:

public void ExportDataSet(DataSet ds)
{

   try
   {
      string filename = "ExcelFile.xls";
      HttpResponse response = HttpContext.Current.Response;
      response.Clear();
      response.Charset = "";
      response.ContentType = "application/vnd.ms-excel";
      response.AddHeader("Content-Disposition", "attachment;filename=\"" + filename + "\"");
      using (StringWriter sw = new StringWriter())
      {
         using (HtmlTextWriter htw = new HtmlTextWriter(sw))
         {
             GridView dg = new GridView();
             dg.DataSource = ds.Tables[0];
             dg.DataBind();
             dg.RenderControl(htw);
             // response.Write(style);
             response.Write(sw.ToString());                                                
             response.End();                    // Exception was Raised at here
         }
      }
   }
   catch (Exception ex)
   {
      string Err = ex.Message.ToString();
      EsHelper.EsADLogger("HOQCMgmt.aspx ibtnExcelAll_Click()", ex.Message.ToString());
   }
   finally
   {                
   }
}

Don't use `Response.End` see http://stackoverflow.com/a/3917180/2864740 (and the other answers); note that the exception is "to be expected" as it is how the stack is unwound (so don't catch that exception). If you still want to catch [other] exceptions, use: `.. catch (ThreadAbortException) { throw; /* propagate */ } catch (Exception ex) { .. }` — user2864740, Jan 08 '14 at 06:31

score 243 · Answer 1 · edited Jul 20 '18 at 11:41

243

I researched online and saw that the Response.End() always throws an exception.

Replace this: HttpContext.Current.Response.End();

With this:

HttpContext.Current.Response.Flush(); // Sends all currently buffered output to the client.
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.

edited Jul 20 '18 at 11:41

Protector one

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answered Mar 12 '14 at 20:44

user3412640

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2

Wow a godsend. It saved me hours of debug using WinDbg. In my case, my w3wp.exe just crashed if there are too many ThreadAbortException – Dio Phung Sep 14 '15 at 05:36
Thanks. This piece of code is really helpful if you want to add some authorization check to asmx service constructor – vadim May 20 '16 at 12:52
This worked for me. I replaced .End() with the suggested code and it works without exception now. Thank You, My working code now is: Response.ContentType = "text/csv"; Response.AddHeader("Content-Disposition",string.Format("attachment;filename=\"{0}\"",Path.GetFileName(filePath))); Response.TransmitFile(filePath); //Response.End(); HttpContext.Current.Response.Flush(); HttpContext.Current.Response.SuppressContent = true; HttpContext.Current.ApplicationInstance.CompleteRequest(); – Nour Lababidi May 20 '16 at 19:23
What's the impact of Response.Redirect("somepage.aspx",true); vs the three lines of code above? Do they do the same thing? – mattpm Oct 28 '16 at 08:43
Working fine without exception!! Well done. But in my code its for PDF and file is not getting generate for dowload. What may be the cause for this ? followed the suggested code as above – Prajwal Bhat Jun 27 '17 at 05:08
working fine for me , and HttpContext.Current.Response.End(); should be last or after complete request – MSTdev Jul 10 '17 at 10:50
3

No. Does not work for me. Actually look at the answer. If `Response.End()` does ***not*** work, why the suggested answer has also `Response.End()` at the last line? Instead the answer from @Binny (below) helps! – Just a HK developer Jul 21 '17 at 01:58
This decreased the volume of errors for me. Roughly 1 of every 100 executions of my handler still throws the error. – crenshaw-dev Jan 19 '18 at 14:32
3

According to documentation at https://learn.microsoft.com/en-us/dotnet/api/system.web.httpresponse.end Request.End is supported only for backward compatibility. CompleteRequest usage is recommended as replacement – Rudolf Dvoracek Jul 03 '18 at 10:59
@MSTdev: The `Response.End()` you added in an edit, was precisely the problem of the original code. :/ – Protector one Jul 20 '18 at 11:44
I ran into this problem and banged my head against it for hours. This fixed it. Thanks! – J.M. Haynes Dec 13 '20 at 06:16
This seemed to work for me too but shouldn't this line: HttpContext.Current.Response.SuppressContent = true; precede the actual transmission of the data by this line in the above example: response.Write(sw.ToString()); Or, in my case, by this line: Response.TransmitFile(ZipFilePath) for it to be effective?? (Using the debugger, I can see that my file is completely transferred by the TransmitFile() call.) – Zeek2 Jun 29 '21 at 15:47
Excelent, this solution helps me, i tried to find a reason why in visual studio worked fine but not on iis, thanks a lot!! – James K Mar 20 '23 at 06:12

Binny · Answer 2 · 2015-09-15T10:53:56.350

This helped me to handle Thread was being aborted exception,

try
{
   //Write HTTP output
    HttpContext.Current.Response.Write(Data);
}  
catch (Exception exc) {}
finally {
   try 
    {
      //stop processing the script and return the current result
      HttpContext.Current.Response.End();
     } 
   catch (Exception ex) {} 
   finally {
        //Sends the response buffer
        HttpContext.Current.Response.Flush();
        // Prevents any other content from being sent to the browser
        HttpContext.Current.Response.SuppressContent = true;
        //Directs the thread to finish, bypassing additional processing
        HttpContext.Current.ApplicationInstance.CompleteRequest();
        //Suspends the current thread
        Thread.Sleep(1);
     }
   }

if you use the following the following code instead of HttpContext.Current.Response.End() , you will get Server cannot append header after HTTP headers have been sent exception.

            HttpContext.Current.Response.Flush();
            HttpContext.Current.Response.SuppressContent = True;
            HttpContext.Current.ApplicationInstance.CompleteRequest();

Hope it helps

Works for me. The above does not. Actually it is funny that while `Response.End()` does not work, but the suggested method has also `Response.End()` at the last line? — Just a HK developer, Jul 21 '17 at 01:59

score 5 · Answer 3 · answered Jul 10 '15 at 18:22

5

Move the Response.End() to outside of the Try/Catch and Using blocks.

It's suppose to throw an Exception to bypass the rest of the request, you just weren't suppose to catch it.

bool endRequest = false;

try
{
    .. do stuff
    endRequest = true;
}
catch {}

if (endRequest)
    Resonse.End();

answered Jul 10 '15 at 18:22

Steve

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why not place that in a Finally block, so it is always executed? – GoldBishop Oct 04 '17 at 19:02
you could do that, especially if you have a return statement in the try block. But if you try/catch/ignore then you don't even need the finally. the important thing is that the you should not catch the ThreadAbortException. – Steve Oct 05 '17 at 22:51
True, the TAE is a PITA for returning a successful Response. – GoldBishop Oct 08 '17 at 15:37

score 4 · Answer 4 · edited May 23 '17 at 12:34

4

Looks to be the same question as:

When an ASP.NET System.Web.HttpResponse.End() is called, the current thread is aborted?

So it's by design. You need to add a catch for that exception and gracefully "ignore" it.

edited May 23 '17 at 12:34

Community

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1

answered Jan 08 '14 at 06:32

robnick

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I call that public void ExportDataSet(DataSet ds) function in many aspx screens and also I am maintaining error logger method for exceptions which are raised at runtime right those exceptions are write into a .txt files. So that same exception is logged in all the aspx screen's txt files.I just want to avoid this exception throws from method declared class file to aspx. Simply i just want to handle this exception at my method declaration class file itself. – user3171957 Jan 08 '14 at 09:52
1

Per comment from user in your question, simply catch the TheadAbortException --> catch (ThreadAbortException) { } – robnick Jan 08 '14 at 09:59
Yes catch that exception with in Method declaration class file it self . – user3171957 Jan 08 '14 at 10:19

user2265251 · Answer 5 · 2017-02-19T17:40:51.173

Just put the

Response.End();

within a finally block instead of within the try block.

This has worked for me!!!.

I had the following problematic (with the Exception) code structure

...
Response.Clear();
...
...
try{
 if (something){
   Reponse.Write(...);
   Response.End();

   return;

 } 

 some_more_code...

 Reponse.Write(...);
 Response.End();

}
catch(Exception){
}
finally{}

and it throws the exception. I suspect the Exception is thrown where there is code / work to execute after response.End(); . In my case the extra code was just the return itself.

When I just moved the response.End(); to the finally block (and left the return in its place - which causes skipping the rest of code in the try block and jumping to the finally block (not just exiting the containing function) ) the Exception ceased to take place.

The following works OK:

...
Response.Clear();
...
...
try{
 if (something){
   Reponse.Write(...);

   return;

 } 

 some_more_code...

 Reponse.Write(...);

}
catch(Exception){
}
finally{
    Response.End();
}

score 4 · Answer 6 · answered Aug 17 '17 at 03:06

4

For me only works

HttpContext.Current.ApplicationInstance.CompleteRequest().

https://stackoverflow.com/a/21043051/1828356

answered Aug 17 '17 at 03:06

elgoya

101
1
4

1

According to documentation at https://learn.microsoft.com/en-us/dotnet/api/system.web.httpresponse.end Request.End is supported only for backward compatibility. CompleteRequest usage is recommended as replacement – Rudolf Dvoracek Jul 03 '18 at 10:59

score 3 · Answer 7 · answered Mar 14 '17 at 13:03

Use a special catch block for the exception of the Response.End() method

{
    ...
    context.Response.End(); //always throws an exception

}
catch (ThreadAbortException e)
{
    //this is special for the Response.end exception
}
catch (Exception e)
{
     context.Response.ContentType = "text/plain";
     context.Response.Write(e.Message);
}

Or just remove the Response.End() if your building a filehandler

score 2 · Answer 8 · answered Sep 22 '17 at 16:38

2

I removed the linkbutton from the UpdatePanel and also commented the Response.End() Success!!!

answered Sep 22 '17 at 16:38

nunopacheco

71
3
11

score 2 · Answer 9 · answered Nov 10 '17 at 06:15

This is not issue but this is by design. The root cause is described in Microsoft Support Page.

The Response.End method ends the page execution and shifts the execution to the Application_EndRequest event in the application's event pipeline. The line of code that follows Response.End is not executed.

The provided Solution is:

For Response.End, call the HttpContext.Current.ApplicationInstance.CompleteRequest method instead of Response.End to bypass the code execution to the Application_EndRequest event

Here is the link: https://support.microsoft.com/en-us/help/312629/prb-threadabortexception-occurs-if-you-use-response-end--response-redi

the-a-monir · Answer 10 · 2021-10-30T12:23:13.827

 My JSON file-download was solved by using the blow code:

     HttpContext.Current.Response.Flush();
     HttpContext.Current.Response.SuppressContent = true;
     HttpContext.Current.ApplicationInstance.CompleteRequest();

 But Excel file-download was solved by the below way:

 try {
      .....
     }
        catch (System.IO.IOException iex)
        {
            throw (iex);
        }
        catch (System.Threading.ThreadAbortException)
        {
            throw new Exception("ABORTED");//make a custom msg here and catch it 
                                           //where required to continue the rest 
                                           //of the work flow.
        }
        catch (Exception exx)
        {
            throw (exx);
        }
        finally
        {
           ....
        }

score 1 · Answer 11 · answered Aug 24 '17 at 17:01

1

the error for Response.END(); is because you are using a asp update panel or any control that using javascript, try to use control native from asp or html without javascript or scriptmanager or scripting and try again

answered Aug 24 '17 at 17:01

Ivan Renteria Vidal

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1
4

score 1 · Answer 12 · answered Jul 15 '20 at 19:55

1

For me it helped to register a button that calls code behind code as a postback control.

protected void Page_Init(object sender, EventArgs e)
{
    ScriptManager.GetCurrent(this.Page).RegisterPostBackControl(btnMyExport);
}

answered Jul 15 '20 at 19:55

user13938019

11
1

score 1 · Answer 13 · answered Feb 24 '21 at 11:31

1

I know, this is an old question, but couldn't find the solution here. After some tries, I found out, that some added "<asp:UpdatePanel" had been the reason.

After (re)moving them, all works fine like before.

answered Feb 24 '21 at 11:31

PepitoPerez

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1

1

Your answer duplicates another answer on a very old thread. – WaitingForGuacamole Feb 24 '21 at 13:15
Read it again, it's not the same answer and two different reason mentioned – PepitoPerez Feb 24 '21 at 20:10
It also duplicates the answer below from 2+ years ago. "If you remove update panels it woks[sp] fine!" – WaitingForGuacamole Feb 24 '21 at 20:13
Ah ok, that one I missed! Sorry. So I delete my very first entry?? :( – PepitoPerez Feb 24 '21 at 20:20
That's your call, I think the "correct" behavior is to remove a duplicate, but sometimes I think the more you see a duplicate called out the more vigilant you become about it. Cheers. – WaitingForGuacamole Feb 24 '21 at 20:26

score 0 · Answer 14 · edited Oct 25 '18 at 10:17

0

I recommend this solution :

Don't use response.End();
Declare this global var : bool isFileDownLoad;
Just after your (response.Write(sw.ToString());) set ==> isFileDownLoad = true;

Override your Render like :

/// AEG : Very important to handle the thread aborted exception

override protected void Render(HtmlTextWriter w)
{
     if (!isFileDownLoad) base.Render(w);
}

edited Oct 25 '18 at 10:17

Suraj Rao

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answered Jan 16 '14 at 15:10

Abdelrahman ELGAMAL

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score 0 · Answer 15 · answered Feb 17 '17 at 08:09

0

flush the response to the client before response.end()

More about Response.Flush Method

So use the below-mentioned code before response.End();

response.Flush();

answered Feb 17 '17 at 08:09

thejustv

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score 0 · Answer 16 · answered Nov 13 '17 at 04:14

0

I used all above changes but still I was getting same issue on my web application.

Then I contacted my hosting provide & asked them to check if any software or antivirus blocking our files to transfer via HTTP. or ISP/network is not allowing file to transfer.

They checked server settings & bypass the "Data Center Shared Firewall" for my server & now our application is able to download the file.

Hope this answer will help someone.This is what worked for me

answered Nov 13 '17 at 04:14

Sushil Jadhav

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While it might work, it does not sound as a solid solution. Are you saying the firewall is disabled completely? That would be a big "no". Or is it customized for your application? Also weird to see a ThreadAbortException on something the datacenter firewall blocks… In other words, not an answer to the question? – Michael May 31 '19 at 11:52

score 0 · Answer 17 · answered Oct 25 '18 at 10:11

0

I found the reason. If you remove update panels it woks fine!

answered Oct 25 '18 at 10:11

W.S.Jayaruwan Sumathirathne

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should be in comment – TarangP Oct 25 '18 at 10:22

score 0 · Answer 18 · answered May 14 '19 at 21:40

I found that the following worked better...

   private void EndResponse()
    {
        try
        {
            Context.Response.End();
        }
        catch (System.Threading.ThreadAbortException err)
        {
            System.Threading.Thread.ResetAbort();
        }
        catch (Exception err)
        {
        }
    }

How to Avoid Response.End() "Thread was being aborted" Exception during the Excel file download

18 Answers18

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