public async Task <IActionResult> DeleteAll()
        {
            if (User.Identity.Name != AuthorizeManager.SuperAdmin)
            {
                return(NotFound());
            }

            // 刪除所有特權用戶 & 賣方產品
            _context.RemoveRange(_context.AuthorizedMember);
            _context.RemoveRange(_context.Product2);

            // 重新添加超級管理員 & 儲存變更
            _context.AuthorizedMember.Add(new AuthorizedMember
            {
                Email         = AuthorizeManager.SuperAdmin,
                InAdminGroup  = true,
                InSellerGroup = true
            });
            await _context.SaveChangesAsync();

            // 刷新權限的HashTable
            AuthorizeManager.RefreshHashTable(_context);

            return(RedirectToAction(nameof(Index)));
        }
        public async Task <IActionResult> DeleteAll()
        {
            if (User.Identity.Name != AuthorizeManager.SuperAdmin)
            {
                return(NotFound());
            }

            // 清空權限 & 會員 & 上架清單
            _context.RemoveRange(_context.AuthorizedMember.Where(m => m.Email != AuthorizeManager.SuperAdmin));
            _context.RemoveRange(_context.Users.Where(m => m.Email != AuthorizeManager.SuperAdmin));
            _context.RemoveRange(_context.Product2);
            await _context.SaveChangesAsync();

            // 刷新權限的HashTable
            AuthorizeManager.RefreshHashTable(_context);

            return(RedirectToAction(nameof(Index)));
        }