最近支付宝改版了，新版支付宝签名验证都是封装好的，只需要配置和调用
public function pay(){
//商户订单号，商户网站订单系统中唯一订单号，必填
$out_trade_no = '27201'.date('YmdHis',time());
//订单名称，必填
$proName = trim($_POST['WIDsubject']);
//付款金额，必填
$total_amount = '0.01';//trim($_POST['WIDtotal_amount']);
//商品描述，可空
$body = '27201';//trim($_POST['WIDbody']);
Vendor('Alipay.aop.AopClient');
Vendor('Alipay.aop.request.AlipayTradePagePayRequest');
//请求
$c = new \AopClient();
$config = C('alipay');
$c->gatewayUrl = "https://openapi.alipay.com/gateway.do";
$c->appId = $config['app_id'];
$c->rsaPrivateKey = $config['merchant_private_key'];
$c->format = "json";
$c->charset= "UTF-8";
$c->signType= "RSA2";
$c->alipayrsaPublicKey = $config['alipay_public_key'];
$request = new \AlipayTradePagePayRequest();
$request->setReturnUrl($config['return_url']);
$request->setNotifyUrl($config['notify_url']);
$request->setBizContent("{" .
" \"product_code\":\"FAST_INSTANT_TRADE_PAY\"," .
" \"subject\":\"$proName\"," .
" \"out_trade_no\":\"$out_trade_no\"," .
" \"total_amount\":$total_amount," .
" \"body\":\"$body\"" .
" }");
$result = $c->pageExecute ($request);
$model = M('c_house_order');
$data = array(
'product_name'=>$proName,
'order_num'=>$out_trade_no,
'total_amount'=>$total_amount,
'description'=>$body,
'user_id'=>1,
'add_time'=>NOW_TIME,
'up_time'=>NOW_TIME
);
$model->add($data);
//输出
echo $result;
}异步通知，直接在你异步通知的方法里面写逻辑，用$_POST去接收支付宝端传过来的参数，进行相对应的数据库插入或者更新。
