更新当前循环中缩略图的缓存。

原型

update_post_thumbnail_cache( WP_Query $wp_query = null )

参数

$wp_query (WP_Query) (Optional)  一个WP_Query实例。默认为$ wp_query全局。

源文件

路径:wp-includes/post-thumbnail-template.php

<?php
...
function update_post_thumbnail_cache( $wp_query = null ) {
	if ( ! $wp_query )
		$wp_query = $GLOBALS['wp_query'];
	if ( $wp_query->thumbnails_cached )
		return;
	$thumb_ids = array();
	foreach ( $wp_query->posts as $post ) {
		if ( $id = get_post_thumbnail_id( $post->ID ) )
			$thumb_ids[] = $id;
	}
	if ( ! empty ( $thumb_ids ) ) {
		_prime_post_caches( $thumb_ids, false, true );
	}
	$wp_query->thumbnails_cached = true;
}
...
?>

其他

英文文档:https://developer.wordpress.org/reference/functions/update_post_thumbnail_cache/