I'm looking for a way to (easily, by preference ;)) create a download link to a file on a separate file server.
The situation is as follows: the application I'm developing (asp.net 2.0 in vb.net but I have a similar issue in c#, either solution works for me) will be run internally for a company.
As is good practice, the file storage and web application are on two separate servers.
I basically need to be able to create a download link to a file, the only available URL i have to access the file is \servername\folder1\folder2\folder3\file.txt (can be any sort of file)
Weblinks simply don't work. This is how it's currently set up:
tablerowfield.Text = String.Format(
"<a href=""\\servername\folder1\folder2\folder3\{0}""
target=""_blank"">Click me</a>",
filename)
Which doesn't work for obvious reasons. It used to be set up to write that file to the application path itself and that worked perfectly, but it isn't good practice and that's why I'm changing it (or trying to).
I read solutions about creating a download page and then having a table in your DB which holds the links and returns the proper web URL for download but the time constraint I am faced with unfortunately doesn't allow me to develop that.
Assuming I can provide a string with the full filepath to the file like the above, what is the easiest way to just create a link that, when clicked, downloads the document?
Note: I have 0 admin rights in this environment. That really isn't helping me. Let's assume I am given the correct link like above and have the appropriate file access rights and such.
UPDATE:
The above example does work in IE, but not in Firefox and Chrome. IE converts it to a file://servername/... link which does what it's supposed to, but FF and Chrome both actively decided that this is unsafe and have disabled it from their browsers.
You can use ASHX file (say, downloadfile.ashx) and use the following code (not tested, but it will be something like that) in it:
Response.Clear();
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment; filename=abc.txt");
Response.WriteFile(Server.MapPath("\\servername\folder1\folder2\folder3\abc.txt"));
Response.End();
and then use this in your anchor tag like:
Click me
Note: You can also pass parameters for downloading different files like:
Click me
and then, in ashx file, use the file name to download the appropriate file.
this piece of code will create a file in download folder with name=hi.txt and content as "thanks god, finally file got downloaded."
Response.Clear();
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment; filename=hi.txt");
Response.Write("thanks god, finally file got downloaded.");
Response.End();
If your file is already there on server then you can use this code in your download button click event like this
protected void downloadpdf_Click(object sender, EventArgs e)
{
Response.Clear();
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment; filename=""downloadName.pdf""");
Response.WriteFile(Server.MapPath(#"~/path of pdf/actualfile.pdf"));
Response.End();
}
\\servername\folder1\folder2\folder3\... is an UNC path which cannot be used from a browser. Because the file(s) are on a separate server, you need an href attribute of the form http://server-name/folder1/folder2/file.txt.
If the server-name is unresolvable by the clients, then you need to first get the IP address of the server and then formulate the href of the form: http://10.1.1.30/folder1/folder2/file.txt
Here is how you get the IP address from server-name:
IPAddress[] host;
host = Dns.GetHostAddresses("server-name");
string ip = host[0].ToString();
EDIT:
I basically need to be able to create a download link to a file
With the ashx solution your application would be reading the file from the server and relaying it to the clients rather than just providing the clients a link to download the file directly from the file server.
Related
In my ASP.NET web application, downloading an output Excel file is sometimes causing an error. In such cases, the file is not downloaded correctly, but instead it's downloaded with XML data, or I get an error:
Could not download the file error
Clicking "retry" enough time makes it work in IE browser.
Note: the output file is downloaded from IIS server where the application was hosted. i.e. C:\inetpub\wwwroot\MyWebApplication\OutputFiles
I am using the following code to download the file:
Response.Clear();
Response.ClearHeaders();
Response.ClearContent();
Response.ContentType = "Application/txt";
string strFileName = (((ASPxButton)sender).CommandArgument).ToString();
string FilePath = MapPath("~/OutputFiles/" + jobNumber + "/" + strFileName);
Response.AddHeader("Content-Disposition", "attachment; filename=" + strFileName);
Response.TransmitFile(FilePath);
Response.Flush();
System.Web.HttpContext.Current.ApplicationInstance.CompleteRequest();
Response.Close();
The above code is working fine but I don't know why there is an error some times. How to solve this issue? Please advice me.
UPDATE: "The file could not download" error is occurred by following scenario,
Two users, download the output files from different path in parallel. I.e (In IE browser) user1 click the download & save button, at the same time user2 click the download & save button (both user download the different files from different path in IIS directory). which means, One user try to download a file while another file is already downloading by another user.
How can fix this issue while parallel download?
Thanks,
Kavin.S
In your system.web node of your web.config alter or add the following where xxxx is the appropriate file size in KB.
<httpRuntime maxRequestLength="xxxx">
https://msdn.microsoft.com/en-us/library/e1f13641(v=vs.71).aspx
I'm rather new to development and I have a problem which I haven't sound a solution for. I can't seem to find if it is possible or not to solve, anyway..
I want to create an asp page which would allow a user to download a whole folder from an ftp server. The ftp server itself is not on the same physical server as the asp site. To further complicate the issue is that I want to use either explicit or implicit transfer which I can't seem to work in a browser.
The webpage acts as an intermediary between the client and the ftp server, and is meant to be as user friendly as possible. eg. the user just have to press download and it automatically downloads from the ftp server without the use of an installed local client.
client -> asp page -> ftp server
client <- ftp server
My problem is that the asp page does not have the permission to create files on the client system. I have managed to connect to the ftp and try to download all files in a folder but the files do not appear on the client in the target folder.
I might just be searching for the wrong terms but I would appreciate any feedback.
when you say "client" I assume you are referring to the asp.net server. In that case you need to check what user the app pool for your website is running under. Then you need to make sure that user has write permissions to the folder you are storing the ftp files in.
The user is most likely network service.
Your ASP site will not be able to write directly to the end user's system. Just think, would you want any website to have direct access to your file system?
You could download the files to a temporary folder on the Web Server, and then use write it in a response to prompt the user to download it.
Here is a SO question regarding downloading files in ASP.NET
From our question's comment discussion, looks like you are looking to provide user with a option to download file which you have collected on server side from ftp server
//Connect to your file
FileStream sourceFile = new FileStream(Server.MapPath(#"FileName"), FileMode.Open);
float FileSize= sourceFile.Length;
//Write the file content to a byte Array
byte[] getContent = new byte[(int)FileSize];
sourceFile.Read(getContent, 0, (int)sourceFile.Length);
sourceFile.Close();
//Build HTTP Response object
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Length", getContent.Length.ToString());
Response.AddHeader("Content-Disposition", "attachment; filename=" + FileName);
Response.BinaryWrite(getContent);
Response.Flush();
Response.End();
Please see if the above code helps.
Also, check out HTTP Response file Attachment Discussion
protected void Page_Load(object sender, EventArgs e)
{
System.IO.File.WriteAllText(#"C:\CallInformation.txt", "Some data");
}
is CallInformation.txt on the Server? Or the client? If it's the server, other than specifying a computer name (#"\Workstation\c$\CallInformation.txt") how can I get it to save the file client side?
It is built on the server. It would be a major security vulnerability if you could create a file on a client without them physically accepting it. You could always send the data to them as a stream and allow them to choose where to save it.
It's on the server. The code behind executes in the context of the web server.
To get a file to download, there are a few ways. One way is to do something along these lines:
Response.ContentType = "image/jpeg";
Response.AppendHeader("Content-Disposition","attachment; filename=SailBig.jpg");
Response.TransmitFile( Server.MapPath("~/images/sailbig.jpg") );
Response.End();
If you are writing a web application, you should understand that the code runs on the server.
So the file is saved on the server.
To send it to the client, you have to write the contents of the file to the response stream.
The file would be create on the server. To write it locally, you would need a client framework other than just the W3C DOM compliant browser, such as Silverlight and (maybe) Flash - and even then the user would be prompted to allow it to happen.
Here's a post that explains how it can be done:
http://www.c-sharpcorner.com/uploadfile/dpatra/read-and-write-file-to-local-file-system-in-silverlight-4/
Hope it helps.
I am uploading my files to a sftp server, which users should be able to download later. Now how they are going to download is, I am showing the files in a grid, with their Names (saved in DB) as LinkButtons.
On the linkbuttons click I am going to download the file from sftp server to a local folder on the server and then, here I directly want to give the file to the user. The link button doesnt have a hard link.
Also, there is no restriction of filetype or size. Please can you suggest anything that could help?
To solve the second problem (sending the locally downloaded file), you basically send the file back to the client as the response to the click event:
From How to send a file to a client so a Download dialog will open?:
string pdfPath = MapPath("mypdf.pdf");
Response.ContentType = "Application/pdf";
Response.AppendHeader("content-disposition",
"attachment; filename=" + pdfPath );
Response.TransmitFile(pdfPath);
Response.End();
I am trying to download a file uploaded from a location on server. Here is the code i am using
to download a file
Response.ContentType = "image/jpg";
Response.AddHeader("Content-Disposition", "attachment;filename=\"" + filePath + "\"");
Response.TransmitFile(Server.MapPath(filePath));
Response.End();
Here i have files of various extensions i.e a file can be a jpg/pdf/doc/txt i am currently setting ContentType to image/jpg.
When i try to download a file than it gets Saved properly and than can be opened from the physical location where it is saved but the Open does not work and the file is not downloaded i get the error as shown in the picture.
This issue is even when i try to Open a file of type jpg so i dont think it is something to do with ContentType
Kindly help.
I specified Content-Type as octet-stream and it worked!
Most typically this problem happens on Internet Explorer with disabled caching (the file is downloaded to temp folder and then deleted before you click Open). See IEInternals.
How to determine this: launch Fiddler and look for caching headers in the file download response.
If the response includes Cache-Control: no-cache header, you will have to modify your code to either override it with Cache-Control: private or change the code where you disable it to exclude the handlers/pages/actions that generate the files (sometimes asp.net has problems overriding Cache-Control headers and thus I usually use the second approach).