TradeModel：

    public  $patchTraderRule = array(
        ....,
        array('patch_tradePSW','checkPSW','密码不正确',0,'function')
    );
    // checkPSW 压根就没执行 怎么办？？
    public function checkPSW($patch_tradePSW){
       return false;
    }

TradeController:

        $Trade = D('Trade');

         if(!empty($_POST)){
             $isValid =  $Trade ->validate($Trade->patchTraderRule)->create();
             if($isValid === false){

                 $this->error($Trade->getError());
             }
             else{
                 //其他业务逻辑
             }
         }