protected function ajaxExecute(MUser $me, MShop $shop)
 {
     $cid = MRequest::post('cid');
     $ps = (int) MRequest::post('ps');
     $pn = (int) MRequest::post('pn');
     $ps = max(0, $ps);
     if (!$pn) {
         $pn = 20;
     }
     try {
         $itemlist = $shop->getShopItems($cid, $ps, $pn);
         $foundrows = $shop->totalCount();
     } catch (Exception $e) {
         return MJsonRespond::respondFail('获取商品列表失败');
     }
     return MJsonRespond::respondSuccess('成功', array('itemlist' => $itemlist, 'total' => $foundrows));
 }