WordPress函数wp_get_attachment_image_src()用法 获取缩略图(特色图像)路径

描述：

获取缩略图(特色图像)的路径（可定义图片的长宽）

用法：

<?php wp_get_attachment_image_src( $attachment_id, $size, $icon ); ?>

参数：

$attachment_id
(integer) (必填) 图片ID
默认值: None
$size
(string/array) (可选) 为图像附件显示的图像大小：字符串关键字（缩略图、中、大或全）或以像素表示宽度和高度的两项数组，例如数组（32,32）。从2.5版起，此参数不影响媒体图标的大小，媒体图标始终以其原始大小显示。
默认值: thumbnail
$icon
(bool) (可选) 使用媒体图标表示附件。
默认值: false

示例：

<?php
$attachment_id = 8; // attachment ID

$image_attributes = wp_get_attachment_image_src( $attachment_id ); // returns an array
if( $image_attributes ) {
?>
<img src="<?php echo $image_attributes[0]; ?>" width="<?php echo $image_attributes[1]; ?>" height="<?php echo $image_attributes[2]; ?>">
<?php } ?>

源文件：

/**
* Retrieve an image to represent an attachment.
*
* A mime icon for files, thumbnail or intermediate size for images.
*
* @since 2.5.0
*
* @param int $attachment_id Image attachment ID.
* @param string|array $size Optional. Registered image size to retrieve the source for or a flat
* array of height and width dimensions. Default 'thumbnail'.
* @param bool $icon Optional. Whether the image should be treated as an icon. Default false.
* @return false|array Returns an array (url, width, height), or false, if no image is available.
*/
function wp_get_attachment_image_src( $attachment_id, $size = 'thumbnail', $icon = false ) {
// get a thumbnail or intermediate image if there is one
$image = image_downsize( $attachment_id, $size );
if ( ! $image ) {
$src = false;

if ( $icon && $src = wp_mime_type_icon( $attachment_id ) ) {
/** This filter is documented in wp-includes/post.php */
$icon_dir = apply_filters( 'icon_dir', ABSPATH . WPINC . '/images/media' );

$src_file = $icon_dir . '/' . wp_basename( $src );
@list( $width, $height ) = getimagesize( $src_file );
}

if ( $src && $width && $height ) {
$image = array( $src, $width, $height );
}
}
/**
* Filter the image src result.
*
* @since 4.3.0
*
* @param array|false $image Either array with src, width & height, icon src, or false.
* @param int $attachment_id Image attachment ID.
* @param string|array $size Registered image size to retrieve the source for or a flat
* array of height and width dimensions. Default 'thumbnail'.
* @param bool $icon Whether the image should be treated as an icon. Default false.
*/
return apply_filters( 'wp_get_attachment_image_src', $image, $attachment_id, $size, $icon );
}