WordPress函数wp_get_attachment_metadata()用法 获取附件的meta数据信息

描述：

获取附件的meta数据信息

用法：

<?php wp_get_attachment_metadata( $attachment_id, $unfiltered ); ?>

参数：

$attachment_id

(integer) (必填) 附件ID

默认值: None

$unfiltered

(boolean) (可选) 如果为true，则不运行筛选器。

默认值: false

返回值：

Array
(
[width] => 2400
[height] => 1559
[file] => 2011/12/press_image.jpg
[sizes] => Array
(
[thumbnail] => Array
(
[file] => press_image-150x150.jpg
[width] => 150
[height] => 150
[mime-type] => image/jpeg
)
[medium] => Array
(
[file] => press_image-4-300x194.jpg
[width] => 300
[height] => 194
[mime-type] => image/jpeg
)
[large] => Array
(
[file] => press_image-1024x665.jpg
[width] => 1024
[height] => 665
[mime-type] => image/jpeg
)
[post-thumbnail] => Array
(
[file] => press_image-624x405.jpg
[width] => 624
[height] => 405
[mime-type] => image/jpeg
)
)
[image_meta] => Array
(
[aperture] => 5
[credit] =>
[camera] => Canon EOS-1Ds Mark III
=>
[created_timestamp] => 1323190643
[copyright] =>
[focal_length] => 35
[iso] => 800
[shutter_speed] => 0.016666666666667
[title] =>
)
)

源文件：

/**
* Retrieve attachment meta field for attachment ID.
*
* @since 2.1.0
*
* @param int $post_id Attachment ID. Default 0.
* @param bool $unfiltered Optional. If true, filters are not run. Default false.
* @return mixed Attachment meta field. False on failure.
*/
function wp_get_attachment_metadata( $post_id = 0, $unfiltered = false ) {
$post_id = (int) $post_id;
if ( !$post = get_post( $post_id ) )
return false;

$data = get_post_meta( $post->ID, '_wp_attachment_metadata', true );

if ( $unfiltered )
return $data;

/**
* Filter the attachment meta data.
*
* @since 2.1.0
*
* @param array|bool $data Array of meta data for the given attachment, or false
* if the object does not exist.
* @param int $post_id Attachment ID.
*/
return apply_filters( 'wp_get_attachment_metadata', $data, $post->ID );
}