Question

image_get_intermediate_size( int $post_id,  array|string $size = 'thumbnail' )

Retrieves the image’s intermediate size (resized) path, width, and height.

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description

The $size parameter can be an array with the width and height respectively. If the size matches the ‘sizes’ metadata array for width and height, then it will be used. If there is no direct match, then the nearest image size larger than the specified size will be used. If nothing is found, then the function will break out and return false.

The metadata ‘sizes’ is used for compatible sizes that can be used for the parameter $size value.

The url path will be given, when the $size parameter is a string.

If you are passing an array for the $size, you should consider using add_image_size() so that a cropped version is generated. It’s much more efficient than having to find the closest-sized image and then having the browser scale down the image.

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参数

$post_id

(int) (Required) 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: 'thumbnail'

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返回值

(false|array) $data { Array of file relative path, width, and height on success. Additionally includes absolute path and URL if registered size is passed to $size parameter. False on failure. @type string $file Image's path relative to uploads directory @type int $width Width of image @type int $height Height of image @type string $path Image's absolute filesystem path. @type string $url Image's URL. }

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源代码

File: wp-includes/media.php

function image_get_intermediate_size( $post_id, $size = 'thumbnail' ) {
	if ( ! $size || ! is_array( $imagedata = wp_get_attachment_metadata( $post_id ) ) || empty( $imagedata['sizes'] )  ) {
		return false;
	}

	$data = array();

	// Find the best match when '$size' is an array.
	if ( is_array( $size ) ) {
		$candidates = array();

		if ( ! isset( $imagedata['file'] ) && isset( $imagedata['sizes']['full'] ) ) {
			$imagedata['height'] = $imagedata['sizes']['full']['height'];
			$imagedata['width']  = $imagedata['sizes']['full']['width'];
		}

		foreach ( $imagedata['sizes'] as $_size => $data ) {
			// If there's an exact match to an existing image size, short circuit.
			if ( $data['width'] == $size[0] && $data['height'] == $size[1] ) {
				$candidates[ $data['width'] * $data['height'] ] = $data;
				break;
			}

			// If it's not an exact match, consider larger sizes with the same aspect ratio.
			if ( $data['width'] >= $size[0] && $data['height'] >= $size[1] ) {
				// If '0' is passed to either size, we test ratios against the original file.
				if ( 0 === $size[0] || 0 === $size[1] ) {
					$same_ratio = wp_image_matches_ratio( $data['width'], $data['height'], $imagedata['width'], $imagedata['height'] );
				} else {
					$same_ratio = wp_image_matches_ratio( $data['width'], $data['height'], $size[0], $size[1] );
				}

				if ( $same_ratio ) {
					$candidates[ $data['width'] * $data['height'] ] = $data;
				}
			}
		}

		if ( ! empty( $candidates ) ) {
			// Sort the array by size if we have more than one candidate.
			if ( 1 < count( $candidates ) ) {
				ksort( $candidates );
			}

			$data = array_shift( $candidates );
		/*
		 * When the size requested is smaller than the thumbnail dimensions, we
		 * fall back to the thumbnail size to maintain backwards compatibility with
		 * pre 4.6 versions of WordPress.
		 */
		} elseif ( ! empty( $imagedata['sizes']['thumbnail'] ) && $imagedata['sizes']['thumbnail']['width'] >= $size[0] && $imagedata['sizes']['thumbnail']['width'] >= $size[1] ) {
			$data = $imagedata['sizes']['thumbnail'];
		} else {
			return false;
		}

		// Constrain the width and height attributes to the requested values.
		list( $data['width'], $data['height'] ) = image_constrain_size_for_editor( $data['width'], $data['height'], $size );

	} elseif ( ! empty( $imagedata['sizes'][ $size ] ) ) {
		$data = $imagedata['sizes'][ $size ];
	}

	// If we still don't have a match at this point, return false.
	if ( empty( $data ) ) {
		return false;
	}

	// include the full filesystem path of the intermediate file
	if ( empty( $data['path'] ) && ! empty( $data['file'] ) && ! empty( $imagedata['file'] ) ) {
		$file_url = wp_get_attachment_url($post_id);
		$data['path'] = path_join( dirname($imagedata['file']), $data['file'] );
		$data['url'] = path_join( dirname($file_url), $data['file'] );
	}

	/**
	 * Filters the output of image_get_intermediate_size()
	 *
	 * @since 4.4.0
	 *
	 * @see image_get_intermediate_size()
	 *
	 * @param array        $data    Array of file relative path, width, and height on success. May also include
	 *                              file absolute path and URL.
	 * @param int          $post_id The post_id of the image attachment
	 * @param string|array $size    Registered image size or flat array of initially-requested height and width
	 *                              dimensions (in that order).
	 */
	return apply_filters( 'image_get_intermediate_size', $data, $post_id, $size );
}

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更新日志

Version	description
2.5.0	Introduced.

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相关函数

Uses

• wp-includes/media.php: wp_image_matches_ratio()
• wp-includes/media.php: image_get_intermediate_size
• wp-includes/functions.php: path_join()
• wp-includes/plugin.php: apply_filters()
• wp-includes/media.php: image_constrain_size_for_editor()
• wp-includes/post.php: wp_get_attachment_metadata()
• wp-includes/post.php: wp_get_attachment_url()
Show 2 more uses Hide more uses

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Used By

• wp-admin/includes/image-edit.php: wp_image_editor()
• wp-admin/includes/image.php: _load_image_to_edit_path()
• wp-includes/media.php: image_downsize()

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User Contributed Notes