Download file and continue page processing

Hello
First time working with asp.net. :)

So i have a page, that has a gridview that after the user clicking in a button i put all the contents of that gridivew in a spreadsheet and allow the user to save it to the desktop...

After creating the file, i need to do 2 things:
- Clear the gridview and put a message in a label in the same page
- After the download, i need to delete the file from the server

If i send the file to the user, i can delete the file, but i can't update the page (clearing the gridview, updating the label).
, the code runs, but the page doesn't "refresh"...

How to do this?

Thanks