Question

wp_get_attachment_image_srcset( int $attachment_id,  array|string $size = 'medium',  array $image_meta = null )

Retrieves the value for an image attachment’s ‘srcset’ attribute.

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description

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参数

$attachment_id

(int) (Required) Image attachment ID.

$size

(array|string) (Optional) Image size. Accepts any valid image size, or an array of width and height values in pixels (in that order).

Default value: 'medium'

$image_meta

(array) (Optional) The image meta data as returned by 'wp_get_attachment_metadata()'.

Default value: null

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返回值

(string|bool) A 'srcset' value string or false.

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源代码

File: wp-includes/media.php

function wp_get_attachment_image_srcset( $attachment_id, $size = 'medium', $image_meta = null ) {
	if ( ! $image = wp_get_attachment_image_src( $attachment_id, $size ) ) {
		return false;
	}

	if ( ! is_array( $image_meta ) ) {
		$image_meta = wp_get_attachment_metadata( $attachment_id );
	}

	$image_src = $image[0];
	$size_array = array(
		absint( $image[1] ),
		absint( $image[2] )
	);

	return wp_calculate_image_srcset( $size_array, $image_src, $image_meta, $attachment_id );
}

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更新日志

Version	description
4.4.0	Introduced.

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相关函数

Uses

• wp-includes/media.php: wp_calculate_image_srcset()
• wp-includes/functions.php: absint()
• wp-includes/media.php: wp_get_attachment_image_src()
• wp-includes/post.php: wp_get_attachment_metadata()

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User Contributed Notes

1. Skip to note content You must log in to vote on the helpfulness of this noteVote results for this note: 0You must log in to vote on the helpfulness of this note Contributed by Drew Jaynes

   Using $size as an array of width and height dimensions:

   
   <?php
   // Specifying width of 400 (px) and height of 200 (px).
   $srcset = wp_get_attachment_image_srcset( get_custom_header()->attachment_id, array( 400, 200 ) );
   ?>
   <img src="<?php header_image(); ?>" srcset="<?php echo esc_attr( $srcset ); ?>">