How to download file without full file path using Response TransmitFile in ASP.NET

Question

How to download file without full file path using Response TransmitFile in ASP.NET

BeUnique 2,332

I am downloading the file using the below code. But, downloading the file is showing the full path of the filename.
Example :
Filaname : Test.asd
File path : \tdsment.tds.intranet\USA\PART1\2022\
current download file (after downloading) : _tdsment.tds.intranet_USA_PART1_2022_Test.asd
I don't want to show the full file path after downloading the file.
Simply my downloaded file should be "Test.asd"
It means Expecting download file name : Test.asd

Public Sub TreeView1_SelectedNodeChanged(sender As Object, e As EventArgs)  
        Dim ChildNode1 As String = TreeView1.SelectedValue  
        filename = GetFileName(ChildNode1)  
        Response.Clear()  
        Using oBinaryReader As BinaryReader = New BinaryReader(File.OpenRead(filename))  
            Response.ContentType = "application/octet-stream"  
            Response.AppendHeader("Content-Disposition", "attachment; filename=" + filename)  
            Response.TransmitFile(filename)  
            Response.Flush()  
        End Using  
End Sub  
Private Function GetFileName(ChildNode1 As String) As String  
        filepath = "\\tdsment.tds.intranet\USA\PART1\2022\"  
        Dim Result As String  
        Result = String.Concat(filepath, ChildNode1)  
        Return Result  
End Function

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Answer 1

AgaveJoe 30,126

Path.GetFileName() returns the file name.

Response.AppendHeader("Content-Disposition", "attachment; filename=" + System.IO.Path.GetFileName(filename))

Reference documentation.

Path.GetFileName Method

Or maybe the ChildNode1 variable contains the file name?

BeUnique 2,332 Reputation points

2022-06-28T12:40:17.957+00:00

Yes. ChildNode variable is a filename and it's mentioning in TreeNode Value itself.

All the filename's like "projectA\Test.asd". So the TreeNode value is Value="ProjectA\Test.asd".

we have to split the filename from the TreeNode Value. ==> (have to implement)

So the final name will be "Test.asd"
AgaveJoe 30,126 Reputation points

2022-06-28T12:55:36.673+00:00
Confused... It seems you made no effort to read the reference documentation in my previous post or try the sample code.

Dim path As String = "ProjectA\Test.asd" Dim file As String = System.IO.Path.GetFileName(path) Console.WriteLine(file)

Results

Test.asd
BeUnique 2,332 Reputation points

2022-06-28T13:09:05.377+00:00

Sorry.It's working..I tested...

Answer 2

Yijing Sun-MSFT 7,096

Hi @BeUnique ,
If you don't have the full path route, you can't download the file. So, your requirement can't be realized. You could rename the filename. As your codes, rename the filename same as "ChildNode". So , Please delete "String.Concat".
Best regards,
Yijing Sun

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BeUnique 2,332 Reputation points

2022-06-28T09:06:59.26+00:00

Thanks for your reply.

I understand your points..

But, if i rename the concern place how it will work...

can you pls. highlight the exact place in the code...?
Albert Kallal 5,586 Reputation points

2022-06-28T17:08:12.37+00:00
Just a bit of confusing here.

When one up-loads a file, we ONLY get the file name. NEVER is any path name information sent from the client side . This is for reasons of security.

however, FEW realize, that when you send a file (download), you CAN include the path name in the file!!!! Now, we have no clue or means to know path names, but you CAN send the full path name!!!!

If you leave out the path name, then it defaults to download folder. This in theory is somewhat of a security risk, since YES a full path name is allowed and used for downloads!!!!

So, the code becomes this:

filename = GetFileName(ChildNode1) dim strFileNameOnly = Path.getFileName(fileName) Response.Clear() Response.ContentType = "application/octet-stream" Response.AppendHeader("Content-Disposition", "attachment; filename=" + strFileNameOnly) Response.TransmitFile(filename) Response.Flush()

So, while TransmistFile MOST certainly needs a full path name , the "strFileNameOnly" has the path stripped out. As I stated, few realized, you ARE permitted to set/have/pass the full path name for a download, but in most cases we should not include the path name information, since that will become and be used as the default download location on the clients computer. But, we don't know path names - or it might be a android phone - so, we have the option to set the file name vs that of the file we transmit - they are SEPERATE concepts.
AgaveJoe 30,126 Reputation points

2022-06-28T17:45:32.873+00:00

When one up-loads a file, we ONLY get the file name. NEVER is any path name information sent from the client side . This is for reasons of security.

It depends on the design. A path or relative path might be needed to make the filenames unique.

/folder1/file.txt
/fodler2/file.txt

The common design pattern for file authorization is storing the files outside the web application and implementing a file handler.
Albert Kallal 5,586 Reputation points

2022-06-28T17:54:11.703+00:00

Oh, yes. But, from the HTML fileup-load, while the client can select any long path name, server side to my knowledge you only ever get JUST the file name - you don't (can't) get user selected file path information when up-loading files.

Its possible that path file information can be had - but I don't think so????

However, when sending (providing download links), or transmit file to the client? yes, you can include file path information and it will be presented (used) as the default download location. However, as I pointed out, in most cases it makes sense to ONLY provide the file name, and not file name + path for that download location. And without providing file path information on the download, then it defaults to the downloads folder.

But, you can in theory if you assume say a windows desktop, you can actually provide a full path name to their desktop, and the file will download to their desktop!! - (but, one would have to guess that location - since they might not even be using windows here).

So up-loads - you only get file name - no path.
So, downloads - you can provide a path name - but it makes little sense to do so!
AgaveJoe 30,126 Reputation points

2022-06-28T18:27:38.657+00:00

The OP asked how to get the file name which is openly illustrated in the System.IO reference docs. Nowhere is the OP asking about local file paths or uploading files.

But, you can in theory if you assume say a windows desktop, you can actually provide a full path name to their desktop, and the file will download to their desktop!!

A web application cannot specify the browser's download folder. However, the UI design can show a virtual file path which may or may not be based on the actual physical file path. The UI design might need enough of a path so the user can select the right file.

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How to download file without full file path using Response TransmitFile in ASP.NET

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