实际上，我有一个专门用于此目的的类：

/**
* Hide_widgets_role_based
* @author Ohad Raz <[email protected]>
*/
class Hide_widgets_role_based{
    $has_selector = false;
    $js_selector = \'\';
    $roles_hide =array();
    /**
     * class constructor
     * @author Ohad Raz <[email protected]>
     * @param array $args [description]
     */
    function __construct($args = array()){
        if (is_admin())
            add_action(\'widgets_init\', array($this,\'hide\', 999));
    }

    /**
     * the money function that hides the widgets on the admin side when the user has a specific role
     * @return void
     */
    public function hide(){
        global $pagenow;
        if ($pagenow == \'widgets.php\'){
            global $current_user;
            get_currentuserinfo();
            $sperator = "";
            foreach ($this->roles_hide as $role => $widgets) {
                if ($this->has_role($role)){
                    foreach ((array)$widgets as $w_id) {
                        unregister_widget( $w_id );
                    }
                }
            }
        }
    }


    /**
     * add a widget to hide per role
     * @param string $role   role name
     * @param string $widget widget id
     */
    public function addHide($role,$widget){
        if (is_array($widget)){
            $tmp = isset($roles_hide[$role])? $roles_hide[$role]: array();
            $roles_hide[$role] = array_merge($tmp, (array)$widget);
        }else{
            $roles_hide[$role][] = $widget;
        }
    }

    /**
     * has_role check if a user has a role
     * @param  int  $user_id user id
     * @return boolean          
     */
    public function has_role($user_id = null){
        if ( is_numeric( $user_id ) )
            $user = get_userdata( $user_id );
        else
            $user = wp_get_current_user();

        if ( empty( $user ) )
        return false;

        return in_array( $role, (array) $user->roles );
    }
}

Usage:

$widgets_hide = new Hide_widgets_role_based();
$widgets_hide->addHide(\'contributor\',array(\'WP_Widget_Pages\',\'WP_Widget_Calendar\',\'WP_Widget_Links\'));
$widgets_hide->addHide(\'editor\',\'WP_Widget_Links\');