php – Zend_Session：必须在将任何输出发送到浏览器之前启动会

Fatal error: Uncaught exception 'Zend_Session_Exception' with message 'Session must be started before any output has been sent to the browser ...

这是我的整个控制器.它显示“成功”,但它也显示错误消息.如何使该错误消息静音,以便我可以简单地向浏览器回应一些内容？

<?php

class CacheController extends Zend_Controller_Action
{
    public function clearAction()
    {
        $this->_helper->layout->disableLayout();
        $this->_helper->viewRenderer->setNoRender();
        try {
            $result = Model_Cache::emptyCache(array('foobar'=>1));

            if ($result['status'] == true) {
                echo 'Success';
            } else {
                echo 'Error: ' . $result['message'];
            }
        } catch (Exception $e) {
            echo 'Error: ' . $e->getMessage();
        }
    }
}