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Download Excel package as file without creating a physical file?

I am looking for code to download a file to a clients pc, I would like to not store the physical file and worry about deleting it at a later stage.
At the moment i create a physical file and then download it, the file name remains the same so it replaces the previous one. My concern is that multiple users might end up overwriting the file when both trying to download at the same time.
Here is some of my code:
using (var package = new ExcelPackage(existingFile))
{
// edit cells and add details into the excel file
//Here u save the file, i would like this to be a stream
using (FileStream aFile = new FileStream(MapPath("../../template/LeadsExport.xlsx"), FileMode.Create))
{
try
{
package.SaveAs(aFile);
aFile.Close();
}
catch (Exception ex)
{
}
}
// Here i download the file, i would like this to use a stream and not a physical file
FileInfo file = new FileInfo(MapPath("../../template/LeadsExport.xlsx"));
Response.Clear();
Response.ClearHeaders();
Response.ClearContent();
Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name);
Response.AddHeader("Content-Length", file.Length.ToString());
Response.ContentType = "text/plain";
Response.Flush();
Response.TransmitFile(file.FullName);
Response.End();
}
I would like to have the package saved into a file stream and not a physical file and then some way to download it.

You already have half the answer, in both code and in your question-text itself. Instead of writing the Excel package to disk, write it to the response stream.
Response.Clear();
Response.AddHeader("content-disposition", "attachment; filename=LeadsExport.xlsx");
Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.BinaryWrite(package.GetAsByteArray());
Response.End();

Cannot download exe files through c#.net

I have designed a website through which when i click a button a .EXE file should download from specific path from my computer.
But its not downloading the exe file instead its downloading the aspx page of the website.
I use the following code:
WebClient myWebClient = new WebClient();
// Concatenate the domain with the Web resource filename.
myWebClient.DownloadFile("http://localhost:1181/Compile/compilers/sample2.exe", "sample2.exe");

Can you please try this.
string filename = "yourfilename";
if (filename != "")
{
string path = Server.MapPath(filename);
System.IO.FileInfo file = new System.IO.FileInfo(path);
if (file.Exists)
{
Response.Clear();
//Content-Disposition will tell the browser how to treat the file.(e.g. in case of jpg file, Either to display the file in browser or download it)
//Here the attachement is important. which is telling the browser to output as an attachment and the name that is to be displayed on the download dialog
Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name);
//Telling length of the content..
Response.AddHeader("Content-Length", file.Length.ToString());
//Type of the file, whether it is exe, pdf, jpeg etc etc
Response.ContentType = "application/octet-stream";
//Writing the content of the file in response to send back to client..
Response.WriteFile(file.FullName);
Response.End();
}
else
{
Response.Write("This file does not exist.");
}
}
I hope my edited comment will help to understand. But note: It is just a rough summary. You can do a lot more than this.

ASP - Prompt save file dialog from streamwriter

Currently I have the text file going to desktop, in ASP how can I prompt a file save dialog for the user? The result is string from the streamreader as "result" as follows:
StreamWriter FileWriter = new StreamWriter(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "file.txt"));
FileWriter.Write(result);
FileWriter.Close();

String FileName = filename;
String FilePath = filepath;
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(FilePath + FileName);
response.Flush();
response.End();

Response.AppendHeader("Content-Disposition", "attachment");
StreamWriter FileWriter = new StreamWriter(Response.OutputStream);
FileWriter.Write(result);
I didn't try the code, but maybe you need to omit the call to FileWriter.Close() since it will try to dispose the stream. If not, then you should be using using instead. If it's too problematic, write to the stream directly with its Write method or use a MemoryStream.

An example from one of my apps that does it.
protected void Page_Load(object sender, EventArgs e)
{
string tempFileName = Request["tempFileName"]; // the temp file to stream
string attachFileName = Request["attachFileName"]; // the default name for the attached file
System.IO.FileInfo file = new System.IO.FileInfo(Path.GetTempPath() + tempFileName);
if (!file.Exists)
{
pFileNotFound.Visible = true;
lblFileName.Text = tempFileName;
}
else
{
// clear the current output content from the buffer
Response.Clear();
// add the header that specifies the default filename for the
// Download/SaveAs dialog
Response.AddHeader("Content-Disposition", "attachment; filename=" + attachFileName);
// add the header that specifies the file size, so that the browser
// can show the download progress
Response.AddHeader("Content-Length", file.Length.ToString());
// specify that the response is a stream that cannot be read by the
// client and must be downloaded
Response.ContentType = "application/octet-stream";
// send the file stream to the client
Response.WriteFile(file.FullName);
}
}

string path = Server.MapPath(your application path);
WebClient client = new WebClient();
byte[] data = client.DownloadData(new Uri(path));
Response.Clear();
Response.ContentType = "application/pdf";
Response.AppendHeader("Content-Disposition", String.Format("attachment; filename={0}", "aspnet.pdf"));
Response.OutputStream.Write(data, 0, data.Length);
try this code.. its helpful

Don't know if its still open but just to help others
Just use this code it should work to prompt the user to open a dialog for opening or saving the file on the system ....
byte[] bytesPDF = System.IO.File.ReadAllBytes(#"C:\sample.pdf");
if (bytesPDF != null)
{
Response.AddHeader("content-disposition", "attachment;filename= DownloadSample.pdf");
Response.ContentType = "application/octectstream";
Response.BinaryWrite(bytesPDF);
Response.End();
}

If I understand you correctly, you first had a 1-tier (desktop) app that was saving a file using C# to the user's file system. You are now trying to transition to a 2-tier app with your C# code running on the server tier, and the user's browser representing the other tier. There is nothing you can do in C# on the server to write a file to the browser user's file system directly.
That being said, what you need to do is write the file to the HTTP response stream with a content type of something like application/octet-stream. Are you actually using ASP or ASP.NET? If the latter, you should have access to the response stream through a variety of means, but start with the Response object (available from the page, but also available via HttpContext.Current.Response).

Response.TransmitFile and delete it after transmission

I have to implement GEDCOM export in my site.
My .net code created one file at server when export to gedcom clicked.
Then I need to download it to client from server, as well as user should be asked where to save that file, meaning savedialog is required.
After it's downloaded, I want to delete that file from server.
I got one code to transmit file from server to client:
Response.ContentType = "text/xml";
Response.AppendHeader("Content-Disposition", "attachment; filename=" + FileName);
Response.TransmitFile(Server.MapPath("~/" + FileName));
Response.End();
from this LINK
but I am not able to delete the file after this code as Response.End ends response so whatever code written after that line is not execute.
If I do code to delete file before Response.End();, then file does not transmitted and I get an error.

Anything you put after Response.End won't get executed because it throws a ThreadAbortException to stop execution of the page at that point.
Try this instead:
string responseFile = Server.MapPath("~/" + FileName);
try{
Response.ContentType = "text/xml";
Response.AppendHeader("Content-Disposition", "attachment; filename=" + FileName);
Response.TransmitFile(responseFile);
Response.Flush();
}
finally {
File.Delete(responseFile);
}

If the file is reasonably small, you can load it into a byte array so that you can delete the file while still being able to send the data:
Response.ContentType = "text/xml";
Response.AppendHeader("Content-Disposition", "attachment; filename=" + FileName);
string path = Server.MapPath("~/" + FileName);
byte[] data = File.ReadAllBytes(path);
File.Delete(path);
Response.BinaryWrite(data);
Response.End();

How to let the user to download an xml file

What i want to do is that the user selects some fields on a grid and according to these datas i create an xml file on the web server and then i want user to download it like downloading a any file. But the problem is, i cant use this code:
Response.ContentType = "APPLICATION/OCTET-STREAM";
// initialize the http content-disposition header to
// indicate a file attachment with the default filename
// "myFile.txt"
System.String disHeader = "Attachment; Filename=\"" + fileName +
"\"";
Response.AppendHeader("Content-Disposition", disHeader);
FileInfo downloadFile = new FileInfo(fileFullName);
if (downloadFile.Exists)
{
Response.WriteFile(downloadFile.FullName);
HttpContext.Current.ApplicationInstance.CompleteRequest();
}
Because i need to let the user download 3 files so the header cannot cary it, what i tought was getting the file names and open a popup, list the file names with a linkbutton, and then the user can download it.
For each file i create a linkbutton at runtime and add this code :
lnkProblem.Text = "Problemler dosyası";
lnkProblem.Visible = true;
lnkProblem.Command += new CommandEventHandler(lnkUser_Command);
lnkProblem.CommandName = Request.QueryString["fileNameProblems"];
lnkProblem.CommandArgument = Request.QueryString["fileNameProblems"];
Then use this function to make it download by the user :
void lnkUser_Command(object sender, CommandEventArgs e)
{
Response.ContentType = "APPLICATION/XML";
System.String disHeader = "Attachment; Filename=\"" + e.CommandArgument.ToString() +
"\"";
Response.AppendHeader("Content-Disposition", disHeader);
FileInfo downloadFile = new FileInfo(Server.MapPath(".") + "\\xmls\\" + e.CommandArgument.ToString());
if (downloadFile.Exists)
{
Response.WriteFile(Server.MapPath(".") + "\\xmls\\" + e.CommandArgument.ToString());
HttpContext.Current.ApplicationInstance.CompleteRequest();
}
HttpContext.Current.ApplicationInstance.CompleteRequest();
}
Application creates the xml file but somewhere of it, app puts the html tags in that xml file so i can't open the file, is there anyway to do this? Maybe any other example...

The cleaneast way to send a file to the client is to use the TransmitFile method like this:
FileInfo file = new FileInfo(filePath); // full file path on disk
Response.ClearContent(); // neded to clear previous (if any) written content
Response.AddHeader("Content-Disposition",
"attachment; filename=" + file.Name);
Response.AddHeader("Content-Length", file.Length.ToString());
Response.ContentType = "text/xml"; //RFC 3023
Response.TransmitFile(file.FullName);
Response.End();
For multiple files a common solution is to pack all files in a zip file and send them (the mime type would be application/zip in this case).

Create a separate IHttpHandler which would only serve files you want your users to download, and Redirect to that handler in lnkUser_Command.