Mail folder is always corrupted after upload

Assuming you need to do this: (for example you cannot provide a direct link)

<a href='<% Eval("Url")) %>'>download</a>

      

        
        
        
      

    

First, I'll make the point that using a RowCommand handler to return a file is not the way to go. Create a link to another page. Separately download files from the rest of the page containing the grid.

Now...

You have the basics right, but as a comment in this CodeProject tutorial , you will run into problems soon.

If the above example code falls down:

• does not respond to user
• the code will continue and you won't have an idea if the user uploaded the file (this may not matter to you)
• won't work with all browsers
• cannot resume download
• does not show progress
• Large files will use more server memory and take longer to stream.
• and a lot of downloads will mean that the server will attack the resource

then as you may want.

• works the same as a click (e.g. with get, not post)
• works in all browsers on all platforms as the user expects (e.g. filename hint works on things like IE for Mac or Netscape 4.1).
• show loading progress
• renewable downloads
• keeping track of all downloads and knowing when downloading is complete
• looks like a file even if it's not
• expiration by url.
• allows you to maintain a high level of simultaneous downloads of files of any size.

Although VB.net1.1 has an article on Tracking and Resuming Large File Uploads in ASP.NET [devx] it explains much better how to do it correctly.

Lightweight code is easy, but doesn't always work, and efficiently streaming files to users. In 100% of cases, it takes a little more work than setting the content header and dragging some bits over the wire.

First, make sure the contents of the file actually look like a zip file. You can do this by simply dropping the file into notepad and looking at the contents. If the file starts with PK and some funny characters, it might be a zip file. If it contains HTML, that could be a clue as to why this is not happening correctly.

Looking at your code, it seemed to me that you are passing the url to the Response.WriteFile file. Does Response.WriteFile handle url or use local filenames? Maybe everything up to Response.WriteFile is working and hence the correct headers are being sent and so on, but then the code crashes with an exception, which could cause your "zip file" to contain an HTML error message.

Edit . So, the first stage of solving the problem is completed. The file looks like a zip file in notepad, not an HTML error message.

Next step, since the file is on the server, try writing the url directly to the file instead of going through your application. It works?

If not, try a different email program (which one are you using by the way?).

As an example why you should try the file directly and different unzipped programs. FinalBuilder creates zip files that PowerArchiver complains about, but 7zip doesn't, so there might be something wrong with the file, your program, or even both.

But make sure the files are correct, they can be opened and if you don't download them at all, and check what happens if you download them directly outside of your application.

Edit . Ok, you confirmed that the file won't open even if you download it directly from your server.

How about opening the file in just explorer, bypassing the entire web server? For example, since it looks like you have the file locally, try just navigating to the right folder and opening the file directly. It works?

Here's the updated code:

fileUrl = e.CommandArgument as String;
                string fileName = Path.GetFileName(fileUrl);

                FileStream fs = new FileStream(fileUrl, FileMode.Open);
                byte[] buffer = new byte[fs.Length];
                fs.Read(buffer, 0, (int) fs.Length);
                fs.Close(); 

                Response.Clear(); 
                Response.AppendHeader("content-disposition",
        "attachment; filename=" + fileName);
                Response.ContentType = "application/octet-stream";
                Response.AppendHeader("content-length", buffer.Length.ToString());

                Response.BinaryWrite(buffer); 
                Response.Flush(); 
                Response.End();