public IActionResult OnPost()
{
if (!ModelState.IsValid)
{
this.Categories = HtmlHelper.GetEnumSelectList <Category> ();
return(Page());
}
if (Book.ISN > 0)
{
BookData.Update(Book);
}
else
{
BookData.Add(Book);
}
BookData.Commit();
TempData["Message"] = "Book Saved";
return(RedirectToPage("./Detail", new { isn = Book.ISN }));
}