wp_get_attachment_thumb_file

检索一个附件的缩略图。

请注意，这只适用于（非常）老的图像元数据风格，其中’thumb’被设置，而’ sizes’数组不存在。对于较新的图像元数据风格，尽管’thumbnail’存在于’size’数组中，该函数仍返回false。

function wp_get_attachment_thumb_file( $post_id = 0 ) {
	_deprecated_function( __FUNCTION__, '6.1.0' );

	$post_id = (int) $post_id;
	$post    = get_post( $post_id );

	if ( ! $post ) {
		return false;
	}

	// Use $post->ID rather than $post_id as get_post() may have used the global $post object.
	$imagedata = wp_get_attachment_metadata( $post->ID );

	if ( ! is_array( $imagedata ) ) {
		return false;
	}

	$file = get_attached_file( $post->ID );

	if ( ! empty( $imagedata['thumb'] ) ) {
		$thumbfile = str_replace( wp_basename( $file ), $imagedata['thumb'], $file );
		if ( file_exists( $thumbfile ) ) {
			/**
			 * Filters the attachment thumbnail file path.
			 *
			 * @since 2.1.0
			 *
			 * @param string $thumbfile File path to the attachment thumbnail.
			 * @param int    $post_id   Attachment ID.
			 */
			return apply_filters( 'wp_get_attachment_thumb_file', $thumbfile, $post->ID );
		}
	}

	return false;
}