public async Task <IActionResult> DeleteCategory(int?categoryId)
        {
            var category = await _context.TblCategory.SingleOrDefaultAsync(m => m.CategoryId == categoryId);

            _context.TblCategory.Remove(category);
            await _context.SaveChangesAsync();

            return(RedirectToAction("Category"));

            /* if (ModelState.IsValid)
             * {
             *   TblCategory tbl = _context.TblCategory.Where(i => i.CategoryId == categoryId) as TblCategory;
             *   _context.TblCategory.Remove(tbl);
             *   _context.SaveChanges();
             * }*/
            // return RedirectToAction("Category");
        }