Develop Reference

Corrupt Excel file output using EPPlus in ASP.NET / C#

I'm trying to use EPPlus to create a report inside an ASP.NET application. I tried using the code provided into samples package but I'm having some troubles.
The following code is executed without error:
ExcelPackage pck = new ExcelPackage();
var ws = pck.Workbook.Worksheets.Add("Sample1");
_ws.Cells["A1"].Value = "COD. CONV.";
_ws.Cells["A1"].Style.Font.Bold = true;
_ws.Cells["A1"].Style.Border.Bottom.Style = OfficeOpenXml.Style.ExcelBorderStyle.Thick;
_ws.Cells["B1"].Value = "RAGIONE SOCIALE";
_ws.Cells["B1"].Style.Font.Bold = true;
_ws.Cells["B1"].Style.Border.Bottom.Style = OfficeOpenXml.Style.ExcelBorderStyle.Thick;
_ws.Cells["C1"].Value = "COMMERCIALE A";
_ws.Cells["C1"].Style.Font.Bold = true;
_ws.Cells["C1"].Style.Border.Bottom.Style = OfficeOpenXml.Style.ExcelBorderStyle.Thick;
_ws.Cells["D1"].Value = "PROVINCIA";
_ws.Cells["D1"].Style.Font.Bold = true;
_ws.Cells["D1"].Style.Border.Bottom.Style = OfficeOpenXml.Style.ExcelBorderStyle.Thick;
_ws.Cells["E1"].Value = "ZONA";
_ws.Cells["E1"].Style.Font.Bold = true;
_ws.Cells["E1"].Style.Border.Bottom.Style = OfficeOpenXml.Style.ExcelBorderStyle.Thick;
_ws.Cells["F1"].Value = "TELEFONO";
_ws.Cells["F1"].Style.Font.Bold = true;
_ws.Cells["F1"].Style.Border.Bottom.Style = OfficeOpenXml.Style.ExcelBorderStyle.Thick;
_ws.Cells["G1"].Value = "EMAIL";
_ws.Cells["G1"].Style.Font.Bold = true;
_ws.Cells["G1"].Style.Border.Bottom.Style = OfficeOpenXml.Style.ExcelBorderStyle.Thick;
int _i = 2;
foreach (DataRow _drRow in dtAnagrafiche.Rows)
{
_ws.Cells["A"+_i.ToString()].Value = _drRow["codice"].ToString();
_ws.Cells["B"+_i.ToString()].Value = _drRow["Nome"].ToString();
_ws.Cells["C"+_i.ToString()].Value = "";
_ws.Cells["D"+_i.ToString()].Value = _drRow["Provincia"].ToString();
_ws.Cells["E"+_i.ToString()].Value = _drRow["Zona"].ToString();
_ws.Cells["F"+_i.ToString()].Value = _drRow["Telefono"].ToString();
_ws.Cells["G"+_i.ToString()].Value = _drRow["Email"].ToString();
_i++;
}
Response.BinaryWrite(_pck.GetAsByteArray());
Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.AddHeader("content-disposition", "attachment; filename=Lista_Anagrafiche.xlsx");
but the resulting file cannot be opened by Microsoft office if not 'recovered', other MS Office compatibile applications (i.e. OpenOffice) cannot open the file.
I can provide the output file if needed.
https://drive.google.com/file/d/0B-lPXYt7laDrbUFKbFZEWEwxckk/view?usp=sharing
BTW I'm using the last (4.0.5) EPPlus package obtained trough nuget, and running it in ASP.NET 4.5 web appplication.

You're missing a call to Response.End(). Without this, you're sending the response with the binary payload (the .xlsx file), which is coming over correctly, then the .aspx page that you're coding this under is being sent in the payload as well. Proof here as shown in a hex editor.
Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.AddHeader("content-disposition", "attachment; filename=Lista_Anagrafiche.xlsx");
Response.BinaryWrite(_pck.GetAsByteArray());
Response.End();
Should do the trick.
As an aside, I would suggest saving the file, then doing a Response.Redirect() to the URL of the file, instead, but that's unrelated to this specific issue.
EDIT: Notably, in normal circumstances, I would suggest avoiding Response.End(), but, that is the quickest way to solve the problem you've coded yourself into. I would suggest looking for better ways to serve up these files in general, as per my above suggestion to Response.Redirect() to a saved location of the file.

Try changing your code to the following notice how I am using the string.Format function to create the filename + extension
you need to declare a constant fileName. if worse comes to worse change the .xlsx to .xls
Response.Clear();
Response.ClearHeaders();
Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.AppendHeader("Content-Disposition", string.Format("attachment;filename={0}.xlsx", fileName));
Response.BinaryWrite(_pck.GetAsByteArray());
Response.Flush();
Response.End();

mp3 files not getting downloaded?

I have written the below lines of code in c#
private void DownloadFile(byte[] myData, string Name)
{
Response.Expires = 0;
Response.Clear();
string ext= System.IO.Path.GetExtension(Name);
switch(ext)
{
case ".mp3":
Response.ContentType = "audio/mpeg";
break;
default:
Response.ContentType = "Application/octet-stream";
break;
}
Response.AddHeader("content-length", myData.Length.ToString());
Response.AddHeader("Content-Disposition", "attachment; filename=" + Name);
try
{
Response.BinaryWrite(myData);
}
catch { }
Response.Flush();
Response.End();
}
Now the issue is that whenever we click mp3 file to download, it's directly played. I want that it should download it. Also I want that all types of files should be downloaded.

I struggled with this for the longest time, but finally solved the puzzle. Use Response.WriteFile. You could follow it with Response.Flush but I found that to be unnecessary. Extra headers were not necessary with .mp3 files. In my case, the .mp3 files were in a folder directly under the root. And here's a bonus: The key ingredients for making the .mp3 download work with smartphones (which was my dilemma) were using Response.End, and telling the mobile device that the download was done by sending back the Response.StatusCode = 200.
string FilenameMP3 = "~/someFolder/xyz.mp3";
string headerFilename = Filename.Substring(Filename.IndexOf("/") + 1);
Response.AppendHeader("Content-Disposition", String.Concat("attachment;filename=\"", headerFilename, "\""));
Response.ContentType = "audio/mpeg";
try
{
Response.WriteFile(Filename, true);
Response.End();
}
finally
{
Response.StatusCode = 200;
Response.Close();
}

What you have should be sufficient, assuming that the headers you added aren't being stripped / corrupted in transit (simple to check via Fiddler or similar).
Since you don't want the browser to interpret this data, a pragmatic option might be to simply send all data as "application/octet-stream", regardless of the content. While the "attachment" disposition should be sufficient for this, this approach is explicitly called out in RFC 2616, 19.5.1 ("Content-Disposition"):
If this header is used in a response with the application/octet- stream content-type, the implied suggestion is that the user agent should not display the response, but directly enter a `save response as...' dialog.

Download text as file in ASP.NET

I am trying to download some text output from the screen as a text file. Following is the code. It's working on some pages and not working at all on other pages. Can anyone please suggest what's wrong here?
protected void Button18_Click(object sender, EventArgs e){
Response.Clear();
Response.Buffer = true;
Response.ContentType = "text/plain";
Response.AppendHeader("content-disposition", "attachment;filename=output.txt");
StringBuilder sb = new StringBuilder();
string output = "Output";
sb.Append(output);
sb.Append("\r\n");
Response.Write(sb.ToString());
}

As already mentioned by Joshua, you need to write the text to the output stream (Response). Also, don’t forget to invoke Response.End() after that.
protected void Button18_Click(object sender, EventArgs e)
{
StringBuilder sb = new StringBuilder();
string output = "Output";
sb.Append(output);
sb.Append("\r\n");
string text = sb.ToString();
Response.Clear();
Response.ClearHeaders();
Response.AppendHeader("Content-Length", text.Length.ToString());
Response.ContentType = "text/plain";
Response.AppendHeader("Content-Disposition", "attachment;filename=\"output.txt\"");
Response.Write(text);
Response.End();
}
Edit 1: added more details
Edit 2: I was reading other SO posts where users were recommending to put quotes around the filename:
Response.AppendHeader("content-disposition", "attachment;filename=\"output.txt\"");
Source:
https://stackoverflow.com/a/12001019/558486

If that's your actual code, you never write the text to the response stream, so the browser never receives any data.
At the very least, you should need
Response.Write(sb.ToString());
to write your text data to the response. Also, as an added bonus, if you know the length beforehand you should provide it using the Content-Length header so the browser can show the download progress.
You're also setting Response.Buffer = true; as part of your method but never explicitly flush the response to send it to the browser. Try adding a Response.Flush() after your write statement.

Response.TransmitFile Not downloading, and throwing no Errors

I'm currently using a HttpResponse to download files from my Server. I already have a couple functions being used to download Excel/Word files, but I'm having trouble getting my simple Text file (.txt) to download.
With the text file I'm basically dumping contents of a TextBox into a File, attempting to download the file with the HttpResponse and then delete the Temporary Text File.
Here is an example of my code that works for the Excel/Word documents:
protected void linkInstructions_Click(object sender, EventArgs e)
{
String FileName = "BulkAdd_Instructions.doc";
String FilePath = Server.MapPath("~/TempFiles/BulkAdd_Instructions.doc");
System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
response.ClearContent();
response.Clear();
response.ContentType = "application/x-unknown";
response.AddHeader("Content-Disposition", "attachment; filename=" + FileName + ";");
response.TransmitFile(FilePath);
response.Flush();
response.End();
}
And here is the chunk of code that doesn't work.
Taking Note that the code runs without throwing any errors. The File is created, and Deleted, but never dumped to the User.
protected void saveLog(object sender, EventArgs e)
{
string date = DateTime.Now.ToString("MM_dd_yyyy_hhmm"); // Get Date/Time
string fileName = "BulkLog_"+ date + ".txt"; // Stitch File Name + Date/Time
string logText = errorLog.Text; // Get Text from TextBox
string halfPath = "~/TempFiles/" + fileName; // Add File Name to Path
string mappedPath = Server.MapPath(halfPath); // Create Full Path
File.WriteAllText(mappedPath, logText); // Write All Text to File
System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
response.ClearContent();
response.Clear();
response.ContentType = "text/plain";
response.AddHeader("Content-Disposition", "attachment; filename=" + fileName);
response.TransmitFile(mappedPath); // Transmit File
response.Flush();
System.IO.File.Delete(mappedPath); // Delete Temporary Log
response.End();
}

It is because you are deleting the file before it can send.
From MSDN - HttpResponse.End Method
Sends all currently buffered output to
the client, stops execution of the
page, and raises the EndRequest event.
Try putting your System.IO.File.Delete(mappedPath); line after the response.End(); in my test just then it seemed to be working.
Also, might be a good idea to check if the file exists first, cant see any file.Exists in there, don't want any null reference exceptions, and to set the Content-Length.
EDIT: here is the code I used in a project at work a while ago, might help you out a bit.
// Get the physical Path of the file
string filepath = System.Web.Hosting.HostingEnvironment.ApplicationPhysicalPath + folder + filename;
// Create New instance of FileInfo class to get the properties of the file being downloaded
FileInfo file = new FileInfo(filepath);
// Checking if file exists
if (file.Exists)
{
// Clear the content of the response
Response.ClearContent();
// LINE1: Add the file name and attachment, which will force the open/cance/save dialog to show, to the header
Response.AddHeader("Content-Disposition", String.Format("attachment; filename={0}", file.Name));
// Add the file size into the response header
Response.AddHeader("Content-Length", file.Length.ToString());
// Set the ContentType
Response.ContentType = ReturnFiletype(file.Extension.ToLower());
// Write the file into the response (TransmitFile is for ASP.NET 2.0. In ASP.NET 1.1 you have to use WriteFile instead)
Response.TransmitFile(file.FullName);
// End the response
Response.End();
//send statistics to the class
}
And here is the Filetype method I used
//return the filetype to tell the browser.
//defaults to "application/octet-stream" if it cant find a match, as this works for all file types.
public static string ReturnFiletype(string fileExtension)
{
switch (fileExtension)
{
case ".htm":
case ".html":
case ".log":
return "text/HTML";
case ".txt":
return "text/plain";
case ".doc":
return "application/ms-word";
case ".tiff":
case ".tif":
return "image/tiff";
case ".asf":
return "video/x-ms-asf";
case ".avi":
return "video/avi";
case ".zip":
return "application/zip";
case ".xls":
case ".csv":
return "application/vnd.ms-excel";
case ".gif":
return "image/gif";
case ".jpg":
case "jpeg":
return "image/jpeg";
case ".bmp":
return "image/bmp";
case ".wav":
return "audio/wav";
case ".mp3":
return "audio/mpeg3";
case ".mpg":
case "mpeg":
return "video/mpeg";
case ".rtf":
return "application/rtf";
case ".asp":
return "text/asp";
case ".pdf":
return "application/pdf";
case ".fdf":
return "application/vnd.fdf";
case ".ppt":
return "application/mspowerpoint";
case ".dwg":
return "image/vnd.dwg";
case ".msg":
return "application/msoutlook";
case ".xml":
case ".sdxl":
return "application/xml";
case ".xdp":
return "application/vnd.adobe.xdp+xml";
default:
return "application/octet-stream";
}
}

I stumbled across this post in my search, and noticed that it wasn't useful in telling us why the UpdatePanel caused the issue in the first place.
The UpdatePanel is an asynchronous postback, and Response.TransmitFile needs a full postback to work properly.
The control that triggers the asynchronous postback needs to be made a trigger in the UpdatePanel:
<Triggers>
<asp:PostBackTrigger ControlID="ID_of_your_control_that_causes_postback" />
</Triggers>

Thank you for the follow up on what your problem was. I've spent hours trying to figure out why no error code was being thrown despite the fact that nothing happened. Turns out it was my AJAX UpdatePanel mysteriously and covertly getting in the way.

I resolved this issue. The Response object requires a full postback in order for it to download an Excel file generated on the server.. but the full postback was being prevented by the UpdatePanel on my webform, which contained my export button. So.. inside the UpdatePanel tag, I changed this...
<asp:AsyncPostBackTrigger ControlID="btnExport" EventName="Click" />
...to this to resolve the issue:
<asp:PostBackTrigger ControlID="btnExport"/>

Also try this for saving text on client side (Chrome only now) without the round trip to Server.
Here is another flash base one...

I ended up fixing the issue on my own. It turns out it was an Ajax Problem not allowing my Button to Postback properly. This stopped the TransmitFile from being fired.
Thanks for the help!

Streaming files and character sets problem

I have made some code which exports some details of a journal article to a reference manager called Endnote
The format of which is a list of items like below (an author):
%A Schortgen Frédérique
Unfortunately, I am having some encoding problems somewhere, as when endnote opens the file, this is what it makes of the above author:
Schortge Frédérique
I have frantically tried playing around with the encoding and stuff that I am outputting and I am at a loss, here is the code:
Response.ContentType = _citation.ContentType;
string fileExtension = "";
if (_citation.GetFileExtension() != null)
fileExtension = "." + _citation.GetFileExtension();
Response.AddHeader("content-disposition", "attachment; filename=citation" + fileExtension);
Response.ContentType = _citation.GetFileReferrer();
Response.Charset = "UTF-8";
Response.write(-snip-);
Response.End();

It looks like Endnote isn't expecting UTF-8. Do you have details of what Endnote does expect? You may find that using Encoding.GetEncoding(1252) or Encoding.GetEncoding(28591) (which are Western codepage 1252 and ISO-8859-1 respectively) might work.
Btw, you're setting Response.ContentType twice. That sounds unlikely to be a good thing.

Response.Charset = "ISO-8859-1";
Response.ContentEncoding = System.Text.Encoding.GetEncoding(28591);
Response.HeaderEncoding = System.Text.Encoding.GetEncoding(28591);
You Sir, are a legend (once again)