CODEWITHSUNDEEP
asp.netdownload
jalgames
jalgames

Reputation: 789

Let the user download a generated file in ASP.Net

I'm creating an ASP.Net web application and I want to add an export feature. That feature will generate a string (xml, to be specific) when a button is clicked.

I want to enable the user to download this string as a file.

Do I need to create a file on the server's hard drive and open a link to that file or is there a way to download the string directly (so ASP.net takes care of creating and removing the file)?

I am currently tryig to do the following:

Response.Clear();
Response.Buffer = true;
Response.ContentEncoding = Encoding.GetEncoding(1252);
Response.ContentType = "application/vnd.ms-excel";
Response.AddHeader("Content-Disposition", "attachment; filename=filename.txls");
//Multiple Response.Write(string) calls to add content to the file
Response.End();

Using firebug, I found out the the user receives the headers, but the file doesn't open.

The Internet Explorer is even able to show me the response text and has a button to save the file (both options are only avilable in the developer tools) and the file is correct, but nontheless, the file still doesn't open a window (nor a in-browser-preview).

When I use the Internet Explorer (which seems to have better Visual Studio debugging integration), a JavaScript error appears:

The EnableScriptGlobalization property cannot be changed during async postbacks or after the Init event.

Calls to Response.Write() seem to be a common cause of this issue. Of course, I call exactly that method multiple times.

I figured out that the JavaScript on the webpage (the script seems to be auto-generated) tries to parse the response, but of course it isn't formatted in the asp.NET internal communication format, but in my own XML format.

How can I tell the page to treat my page as a downloadable file?

Upvotes: 0

Views: 693

Answers (2)

jalgames
jalgames

Reputation: 789

The problem was that the button responsible for triggering the Excel export was not a PostBackTrigger. As soon as I had changed it, everything worked like a charm.

Nontheless, I don't know hy this fixed everything. What does it change when I set the button as a PostBackTrigger

Upvotes: 0

mason
mason

Reputation: 32694

string someXML=GetXMLContent();//I assume you have an implementation of this
Response.Clear();
Response.ContentType = "text/xml";
Response.AddHeader("Content-Disposition", "attachment; filename=filename.xml");
Response.Write(someXML);
Response.End();

Couple of things to note. It's probably better to build up your XML string early on, then write it to the response in one shot. It makes for cleaner code, because you can separate your concerns this way.

Also, I switched the content type to "text/xml", because this is not an Excel file. Also, your file extension was incorrect. XML by convention ends in .xml. I removed the content encoding because it's not necessary most of the time. If you're dealing with weird characters feel free to add it back. Also removed the buffer in the name of removing unnecessary things.

Try this, then try opening the resulting file in your text editor and verifying the content.

Upvotes: 1

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