我重写了代码库，并在分页时停止。如何获得最大页数？目前我无法定义它，并对数字5进行了测试。

 (Here "for ($ i = 1; $ i <= 5; $ i ++)" here "if ($ paged <5))."

如何在分页中设置work offset参数？现在，当我放置参数offset时，分页将无法正常工作。我需要发布16 图片post_per_page was equal to 4. 我还没有为我的具体案例找到解决方案。也许可以用什么东西来代替？这是我的完整代码funсtions.php

    remove_shortcode("gallery");
add_shortcode("gallery","my_gallery");

function my_gallery($atts){
    $img_id = explode(\',\', $atts[\'ids\']);
    if(!$img_id[0]) {
        return \'<div class="no-img-gallery">No images</div>\';
    }

    $paged = get_query_var(\'paged\') ? get_query_var(\'paged\') : 1;
    $pictures = get_posts( array(
        \'posts_per_page\' => 4,
        \'post__in\'       => $img_id,
        \'paged\' => $paged,
        \'post_type\'      => \'attachment\',
    ) );

    $html = \'<div class="gallery-my">\';
    foreach ($pictures as $item){

        $img_desc = $item->post_content;
        $img_caption = $item->post_excerpt;
        $img_title = $item->post_title;
        $img_thumb = wp_get_attachment_image_src($item->ID);
        $img_full = wp_get_attachment_image_src($item->ID,medium);


        $html .="
        <div class=\'item-gallery\'>
            <a href=\'{$img_full[0]}\'>
                <img src=\'{$img_thumb[0]}\' width=\'{$img_thumb[1]}\' height=\'{$img_thumb[2]}\' alt=\'{$img_title}\'>
            <div class=\'desc-wrap\'>
                    <strong class=\'title-img\'>{$img_title}</strong>
                    <span class=\'desc-img\'>{$img_desc}</span>
                </div>
            </a> 
        </div>";

    }

    $html .= "</div>";
//Pagination
    $html .= "<div class=\'pagination-gallery\'>";
        if ($paged > 1) { 
            $html .="<span class=\'prev-cust\'>
                        <a href=\'?paged=".($paged-1)."\'><</a>
                    </span></div>";
        }
        for($i=1;$i<=5;$i++){
            $html .="<span class=\'num-pag\'>
                <a href=\'?paged=".$i."\'";

            if($paged==$i){
                 $usl=\'class="selected"\';
            }
            else{
                 $usl=\'\';
            }

            $html .=$usl.">".$i."</a></span>";
        }
        if ($paged < 5) { 
            $html .="<span class=\'prev-cust\'>
                        <a href=\'?paged=".($paged+1)."\'>></a>
                    </span></div>";
        }

    $html .= "</div>";                              


    return $html;

}