I have to give one option in my website to upload multiple files and then allowing users to download those files.
I have done uploading multiple files part, however I am not much clear how I will do downloading part.
I first thought to add hyperlinks dynamically to a label for each file (as I am not sure how many files user will upload).
But then it opens file in browser and does not give option to save or open file.
Main issue is user can submit any type of file like ms doc or xls or text files etc Hence content type is not fixed.
I am not clear on how exactly I will do it I mean adding link buttons dynamically or adding hyperlinks dynamically. And after that how will I download file? I am not able to do
Response.WriteFile(Server.MapPath(#"~/logo_large.gif"));
as content type is not clear.
Please help me regarding code for download all types of files
for download the file:
public void DownLoad(string FName)
{
string path = FName;
System.IO.FileInfo file = new System.IO.FileInfo(path);
if (file.Exists)
{
Response.Clear();
Response.AddHeader("Content-Disposition", "attachment; filename=" + file.Name);
Response.AddHeader("Content-Length", file.Length.ToString());
Response.ContentType = "application/octet-stream";
Response.WriteFile(file.FullName);
Response.End();
}
else
{
Response.Write("This file does not exist.");
}
}
but this is for word doc/docx files. in the line: Response.ContentType = "application/octet-stream"; you have to define the type of the file.
for displaying hyperlink dynamically write a loop and go over all the files which were uploaded by the user and writh the following code:
yourdivId += "<a href='" + file.FullName + "' >" + file.Name + "</a></br>";
Hope this will help u.()
Response.Clear();
Response.ContentType = YourFile.ToString();
Response.AddHeader("Content-Disposition", "attachment;filename=" + YourFileName);
Response.OutputStream.Write(YourFile, 0, YourFile.Length);
Response.Flush();
Response.End();
I have tried this to download img,txtfile,zip file,doc it works fine..
but little problem user will face that in my case when i opened a word(doc) file its ask
me to openwith..? when i select MsWord it opened it correctly.
For showing these file you can make a grid view to show all file with a download link...
Actually you can follow different ways.
Guide the user during upload and make him specify the file type before starting upload. So the user has to select the content type from a selection. You need to save the correlation between the file and its content type.
Create a map between file extensions and mime-types (See here for example). You need to obtain the file extension and save the correlation between that file and its content type.
Try to identify the content type automatically. There is a Windows
API that let you identify the Mime Type of a file. And here is some code.
After that, you can use st mnmn solution.
You can do it like this:
try
{
string strURL=txtFileName.Text;
WebClient req=new WebClient();
HttpResponse response = HttpContext.Current.Response;
response.Clear();
response.ClearContent();
response.ClearHeaders();
response.Buffer= true;
response.AddHeader("Content-Disposition","attachment;filename=\"" + Server.MapPath(strURL) + "\"");
byte[] data=req.DownloadData(Server.MapPath(strURL));
response.BinaryWrite(data);
response.End();
}
catch(Exception ex)
{
}
You'll have to set few response headers before server sends the file to client. See How to Download a file with a hyperlink
Related
I'm newbie on asp.net, i am developing Online Report Generator, i want to let the client to choose where he/she want to put his/her files so this is my code but didn't seems to work, it returning to my ajax error statement my ConfigurationManager.AppSettings["ExtractFolder"] is equal to "c:\temp\": just want to ask what's wrong with the code?
context.Response.ContentType = "application/vnd.ms-excel";
context.Response.AddHeader("content-disposition", "attachment;filename="+filename);
context.Response.WriteFile(ConfigurationManager.AppSettings["ExtractFolder"]+filename);
context.Response.Flush();
context.Response.End();
Try this
String FileName = "FileName.txt";
String FilePath = "C:/...."; //Replace this
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);
response.Flush();
response.End();
For more content types check our http://en.wikipedia.org/wiki/MIME_type#List_of_common_media_types
Basically you can't do what you want to do the way you are trying to do it.
The ASP.net code that you have is dependant on being part of a full http Request/Response cycle. The part where it is setting headers is where it telling the browser to download stuff.
An AJAX request is looking for a specific return with its request, generally javascript passable data. You are not returning this but rather the contents of a file.
Here's an article the explains the concepts and problems a little more. It also provides you an alternate solution. Basically the solution revolves around using an iFrame to handle the file download request.
First, check that your source file you want to send to the user is in c:\temp\ and that you have set filename to the name of the file you are sending. Next you will want to make sure that your .net process has permission to c:\temp on your server. It probably doesn't.
Also, make sure you understand that response.writefile actually reads a file from the server and writes it out to the browser. You can't specify where the user saves the file to locally, this is handled by the browser not by your code.
Using Coders sample code make sure you change the following (see my comments)
String FileName = "FileName.xlsx"; //MAKE SURE THIS IS YOUR EXCEL FILENAME ON YOUR SERVER
String FilePath = "C:/...."; //SET THIS TO THE FOLDER THE FILE IS IN (put your file in your root folder of your website for now, you can move it later once you get the download code working)
System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
response.ClearContent();
response.Clear();
response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"; //MAKE SURE YOU HAVE CHANGED THIS TOO
response.AddHeader("Content-Disposition", "attachment; filename=" + FileName + ";");
response.TransmitFile(FilePath);
response.Flush();
response.End();
I also suggest trying the above in a standalone page first then incorporate it into your AJAX page once you know its working.
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();
It shouldn't be this hard to find out how to do this. Basically I'm trying to take a string and let the client save it when they click a button. It should pop up with a Save/Open dialog. No extra bells and whistles or anything. It's not rocket science, (or so I would've thought).
There seems to be a ton of different ways, (StreamWriter, HttpResponse, etc.), but none of the examples I've been able to find work properly or explain what's going on. Thanks in advance.
An example one of the many blocks of code I've found...
(This is just an example, feel free to not base your answer around this.)
String FileName = "FileName.txt";
String FilePath = "C:/...."; //Replace this
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);
response.Flush();
response.End();
Line 2 says to replace that string. How? This code was advertised as bringing up a dialog. I shouldn't be having to set a path in the code, right?
EDIT: Final Outcome (Edited again, Delete has to come before End();)
string FilePath = Server.MapPath("~/Temp/");
string FileName = "test.txt";
// Creates the file on server
File.WriteAllText(FilePath + FileName, "hello");
// Prompts user to save 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(FilePath + FileName);
response.Flush();
// Deletes the file on server
File.Delete(FilePath + FileName);
response.End();
Line 2 (FilePath) indicates the path to the file on the server
Line 8:
response.TransmitFile(FilePath);
Transmits that specific file to the client and THAT is what pops the save dialog.
If you don't transmit the file, I'm not sure if the dialog will pop up at all (even though you set a header)
Anyways, I think line 8 should read:
response.TransmitFile(FilePath + FileName);
There will be a default dialog box by browser, if it will find Response as some file. If you want browser to display that default dialog box, all you need to do is send response to browser as file, which you can do in number of ways:
If it is a static file,
best way is to just mention path of file in anchor tag's href.(obviously if you don't have security concern)
Just out along with your response, the way it is done in your example.
Other ways you can refer here 4 ways to send pdf from asp.net
If it is a dynamic file which you need to generate at run time, you can do a trick, generate the file from filestream, put it in some temporary folder at server, read it back as a static file as mentioned above.
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();
}
FilePath is supposed to point to the file you want to send to the client. This is the path on the server.
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.
How can I force the Save As Dialog box to show within an asp.net page without getting the browser bar at the top saying "To help protect security IE blocked this site from downloading files..... Click here for options"
It then forces the user to click the Download File option - but this first time they do this nothing happens.
What I need to happen is that the File Download box should be displayed with the options of saving or opening etc.. the file to download.
The asp.net/C# code I am currently using is:
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment; filename=myfilename");
Response.WriteFile(myfilename);
Response.End();
Any ideas why I shouldn't just get the File Download box ?
Try to change the Content Type to "Application/Force-Download" instead
ASP.NET C# Example:
Response.AppendHeader("Content-Type", "application/force-download;");
Fully functional code:
try
{
string FileName = Request.QueryString["file"];
Response.AppendHeader("Content-Type", "application/force-download;");
Response.AppendHeader("Content-Disposition", "attachment; filename=" + FileName);
Response.WriteFile(#Server.MapPath("download/") + "\\" + FileName);
Response.End();
}
catch (Exception)
{
//Handle Error
}