假设在一个页面中添加了N张图片，想要从中随机获取不重复的三张图片，形成一个幻灯片的DOM结构。
如下结构：

<div class="slider">
    <div class="slide">
        <img src="http://10/wp-content/uploads/2060/03/8.jpg" alt="">
    </div>
    <div class="slide">
        <img src="http://10/flamme/wp-content/uploads/2060/03/9.jpg" alt="">
    </div>
    <div class="slide">
        <img src="http://10/flamme/wp-content/uploads/2060/03/4.jpg" alt="">
    </div>
</div>

设定页面别名（slug）为： home-featured-images
那么，下面的前端代码即可帮助你生成你想要的东西：

<div class="slider">
    <?php $home_gallry_args = array(
    'post_type' => 'page',
    'pagename' => 'home-featured-images',
);
$home_gallery_query = new WP_Query($home_gallry_args);
if ($home_gallery_query->have_posts()) {
    while ($home_gallery_query->have_posts()) {
        $home_gallery_query->the_post();
        $home_gallery_data = get_the_content();
        preg_match_all('/<img .*?(?=src)src=\"([^\"]+)\"/si', $home_gallery_data, $allpics);
        $home_gallery_images = array();
        foreach ($allpics[1] as $pics) {
            array_push($home_gallery_images, $pics);
        }
        $arr = $arr_history = $home_gallery_images;
        $selected_home_gallery_items = array();
        for ($i = 0; $i < 3; $i++) {
            if (empty($arr_history)) {
                $arr_history = $arr;
            }
            $key = array_rand($arr_history, 1);
            $selected = $arr_history[$key];
            unset($arr_history[$key]);
            array_push($selected_home_gallery_items, $selected . PHP_EOL);
        }
        foreach ($selected_home_gallery_items as $selected_home_gallery_item) {
            ?>
    <div class="slide">
        <img src="<?php echo esc_url($selected_home_gallery_item); ?>" alt="<?php bloginfo('name');?>">
    </div>
    <?php
}
        ?>
    <?php }} else {?>
    <div class="slide">
        <img src="<?php bloginfo('template_url');?>/assets/img/f1.jpg" alt="<?php bloginfo('name');?>">
    </div>
</div>
<?php }?>
</div>

上列代码结尾处的else是，如果没有该页面，那么默认输出一张存放在主题文件夹中存放的某个图片。