ThinkPHP の学習 (4) volist タグの高度なアプリケーションのための複数のネストされたループ

    public function index(){		$prod = I("get.prod_en");		$id = I("get.id", 0, "int");		if ($prod == ""){			$serviceProduct = array();//多重循环遍历的数组

//数据保存在两张表中，这里通过循环初始化$serviceProduct数组			$service = M("product_class")->order("oid ASC")->select();			for ($i = 0; $i < count($service); $i++)			{				array_push($serviceProduct, array("srvName"=>$service[$i]["pc_cn"], "product"=>M("product")->where("prod_class_id=".$service[$i]["pcid"])->order("oid ASC")->select()));			}

//如果要在模板中输出变量，必须在在控制器中把变量传递给模板，系统提供了assign方法对模板变量赋值，无论何种变量类型都统一使用assign赋值。			$this->assign("serviceProduct", $serviceProduct);			$this->display();		}else{			if ($id > 0){				$this->display("detail");			}else{				$this->assign('prod_en', $prod);				$clsList = M("question_class")->order("oid ASC")->select();				$this->assign('clsList', $clsList);								$qusList = M("question")->order("oid ASC")->select();				$this->assign('qusList', $qusList);				$this->display("list");			}		}	}

	<volist name="serviceProduct" id="sp" key="i">		<dl class="dlist odd">			<dt>{$sp.srvName}</dt>			<volist name="sp.product" id="pd" key="j">				<dd><a href="/index.php/question?prod_en={$pd.prod_en}">{$pd.prod_cn}</a></dd>				<if condition="$j lt count($sp['product'])">				<dd>|</dd>				</if>			</volist>			<if condition="count($sp['product']) EQ 0">				<dd> </dd>			</if>		</dl>	</volist>

<if condition="$j lt count($sp['product'])">