public string Upload(HttpPostedFileBase FileData) {}
is correct – the file uploaded by uploadify will get binded to FileData. No need to get into Request.Files to retrieve the file – which makes it harder to mock and test.
If your action isn’t firing at all (i.e. try debugging and see if a breakpoint within the method is hit), then your issue is most likely the ‘script’ value – are you running under a virtual directory? If so you’ll need to put the name of the directory in front. Uploadify is using an absolute path.
i.e. ‘script: ‘/virtual_directory/Placement/Upload’
right now uploadify is sending to http://localhost/Placement/Upload.
also try using the route debugger (http://haacked.com/archive/2008/03/13/url-routing-debugger.aspx) to check where your route is being mapped to.