public async Task <RedirectToPageResult> OnGetAsync(int id) { TodoItem = await _context.TodoItems.FirstOrDefaultAsync(t => t.TodoItemId == id); if (TodoItem.DateDone != null) { TodoItem.DateDone = null; } else { TodoItem.DateDone = DateTime.Now; } _context.Attach(TodoItem).State = EntityState.Modified; await _context.SaveChangesAsync(); return(RedirectToPage("./Index")); }