我想上传一张图片并附加一个类别。这是我的代码：

function upload_cover(WP_REST_Request $request) {

    require_once( ABSPATH . \'wp-admin/includes/image.php\' );
    require_once( ABSPATH . \'wp-admin/includes/file.php\' );
    require_once( ABSPATH . \'wp-admin/includes/media.php\' );

    $attachment_id = media_handle_upload(\'poster\', 0);
    $event = array(
        \'post_status\' => \'publish\',
        \'post_type\'   => \'poster\',
        \'meta_input\'  => array(),
        \'post_category\' => array(\'poster\')
    );
    $post_id = wp_insert_post( $event );
    wp_set_post_terms($post_id, \'poster\', \'category\');
}

上传器工作正常，但图像没有附加任何类别。我尝试了以下方法：

$cat_id = get_cat_ID(\'cover\');

add_term_meta( $cat_id, \'poster\', $post_id, true );
wp_set_post_categories($post_id, array(\'poster\'), true);
wp_set_post_terms($post_id, array(\'poster\'), \'category\');

对于图像的类别，我使用这个插件Media Library Categories.

function wp_add_categories_to_attachments() {
    register_taxonomy_for_object_type( \'category\', \'attachment\' );
}
add_action( \'init\' , \'wp_add_categories_to_attachments\' );