我想循环浏览Woocommerce产品目录,并在下拉列表中显示它们

我想循环浏览 Woocommerce产品目录 并将其显示在 下拉列表 。我几乎尝试了互联网上的每一段代码,但似乎都不适合我。我对wordpress很陌生。有人能帮我吗?目前我正在使用此代码,但它没有返回任何内容。

<?php

$taxonomy = 'product_cat';
$orderby = 'name';
$show_count = 0;      // 1 for yes, 0 for no
$pad_counts = 0;      // 1 for yes, 0 for no
$hierarchical = 1;      // 1 for yes, 0 for no  
$title = '';
$empty = 0;

$args = array(
    'taxonomy' => $taxonomy,
    'orderby' => $orderby,
    'show_count' => $show_count,
    'pad_counts' => $pad_counts,
    'hierarchical' => $hierarchical,
    'title_li' => $title,
    'hide_empty' => $empty
);
$all_categories = get_categories($args);
foreach ($all_categories as $cat) {
    if ($cat->category_parent == 0) {
        $category_id = $cat->term_id;
        echo '<br /><a href="' . get_term_link($cat->slug, 'product_cat') . '">' . $cat->name . '</a>';
        ?>
        <?php

        $args2 = array(
            'taxonomy' => $taxonomy,
            'child_of' => 0,
            'parent' => $category_id,
            'orderby' => $orderby,
            'show_count' => $show_count,
            'pad_counts' => $pad_counts,
            'hierarchical' => $hierarchical,
            'title_li' => $title,
            'hide_empty' => $empty
        );
        $sub_cats = get_categories($args2);
        if ($sub_cats) {
            foreach ($sub_cats as $sub_category) {
                echo $sub_category->name;
            }
        }
    }
}
?>