我在这里需要做的是从媒体库中仅按其类别获取图像。它不会附在帖子上，也就是说，该图片不会作为任何帖子类型的“特色图片”上传。它将直接通过媒体库上传。然而，我创建了一个函数，允许我将自定义类别应用于这些图像。我成功地从媒体库中提取了以下图像：

$query_images_args = array(
\'post_type\' => \'attachment\',
\'post_mime_type\' =>\'image\',
\'post_status\' => \'inherit\',
\'posts_per_page\' => -1,
);

$query_images = new WP_Query( $query_images_args );
$images = array();
foreach ( $query_images->posts as $image) {
    $images[]= wp_get_attachment_url( $image->ID );
}

这是我对类别的自定义函数：

function add_attachment_taxonomy() {
$labels = array(
    \'name\'              => \'Categories\',
    \'singular_name\'     => \'Category\',
    \'search_items\'      => \'Search Category\',
    \'all_items\'         => \'All Category\',
    \'parent_item\'       => \'Parent Category\',
    \'parent_item_colon\' => \'Parent Category:\',
    \'edit_item\'         => \'Edit Category\',
    \'update_item\'       => \'Update Category\',
    \'add_new_item\'      => \'Add New Category\',
    \'new_item_name\'     => \'New Category Name\',
    \'menu_name\'         => \'Categories\',
);

$args = array(
    \'labels\' => $labels,
    \'hierarchical\' => true,
    \'query_var\' => \'true\',
    \'rewrite\' => \'true\',
    \'show_admin_column\' => \'true\',
);

register_taxonomy( \'attachment_category\', \'attachment\', $args );
}
add_action( \'init\', \'add_attachment_taxonomy\' );

但是当我添加\'category_name\' => term_slug 它仍然没有显示任何东西。我还需要做些什么来完成这项工作吗？

$query_images_args = array(
    \'post_type\' => \'attachment\',
    \'post_mime_type\' =>\'image\',
    \'post_status\' => \'inherit\',
    \'posts_per_page\' => -1,
    \'tax_query\' => array(
        array(
            \'taxonomy\' => \'attachment_category\',
            \'field\'    => \'slug\',
            \'terms\'    => \'SLUG OF YOUR TERM\',
        ),
    ),
);
$query_images = new WP_Query( $query_images_args );