我正在尝试在显示自定义循环的主题页上交替背景：

$args = array( \'post-type\' => \'portfolio\', \'posts_per_page\' => 10 );
                        $loop = new WP_Query( $args );
                        $count = 0;
                        while ($loop->have_posts() ) : $loop->the_post();

<div class="wrapper <?php if(++$count%2==0) echo \'grey-box\'; else echo \'white-box\'; ?>">

<div class="portfolio-picture <?php if(++$count%2==0) echo \'portfolio-grey-box\'; else echo \'portfolio-white-box\'; ?>">

                        <?php $videocode = get_post_meta($post->ID, \'video-embed-code\', true); //is the custom field being used?

                        if ($videos) {

                            echo $videocode;

                        }

                        else

                        if ( has_post_thumbnail() ) {
                            the_post_thumbnail(\'portfolio-picture\');

                        };

                        ?>

                    </div>



                    <div class="portfolio-description">

                        <p><strong><?php the_title(); ?></strong></p>


                        <p><?php the_content(); ?></p>


                </div>

                <div class="clear"></div>

            </div>
                <?php endwhile; ?>