Unable to delete file (jpeg)

I implemented helper for showing thumbnails from here. Next to the thumbnail, there is a delete link which calls this controller:

// HTTP POST: /Photo/Delete/1
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Delete(int id, string confi开发者_开发问答rmButton)
{
    var path = "~/Uploads/Photos/";            

    Photo photo = photoRepository.GetPhoto(id);

    if (photo == null)
        return View("NotFound");            

    FileInfo TheFile = new FileInfo(Server.MapPath(path + photo.PhotoID + ".jpg"));    

    if (TheFile.Exists)
    {
        photoRepository.Delete(photo);
        photoRepository.Save();

        TheFile.Delete();
    }
    else return View("NotFound"); 

    return View();
}

If I disable showing thumbnails then the file is deleted. Otherwise it sends error:

System.IO.IOException: The process cannot access the file 'C:\Documents and Settings\ilija\My Documents\Visual Studio 2008\Projects\CMS\CMS\Uploads\Photos\26.jpg' because it is being used by another process.

I also don't know if my file delete function is properly written. Searching on the net, I see everyone uses File.Delete(TheFile);, which I'm unable to use and I use TheFile.Delete();. When using File.Delete(TheFile); I get following error:

Error 1 'System.Web.Mvc.Controller.File(string, string, string)' is a 'method', which is not valid in the given context C:\Documents and Settings\ilija\My Documents\Visual Studio 2008\Projects\CMS\CMS\Controllers\PhotoController.cs 109 17 CMS

Am I missing something here?

It's because, as it says, another process has gained a handle on your file, therefore you cannot delete it. In this case the thumbnail generator grabbed a handle of your file, preventing you from deleting it. You have to close all handles on a file in your program in order to delete it.