问致命错误:在没有对象上下文但一切看起来都很好的情况下使用$this

EN

<?php
class acController {

    protected $_enabledPages = array(
        'front_login.php',
    );

    protected $_enabledDirectories = array (
        'admin'
    );

    public static function isAuthorized() {
        echo '<pre>';
        acController::checkResource($_SERVER['SCRIPT_URI'], $this->_enabledDirectories);
        acController::checkResource($_SERVER['SCRIPT_URI'], $this->_enabledDirectories);
        echo '</pre>';
    }

    protected static function checkResource($urlAddress, $addressArray) {}
}