我认为最好依靠 wordpress 的原生wp_get_attachment_image_src()
功能来获得不同大小的图像。但要这样做,您需要附件 ID,而不是 url。将 url 转换为 ID 的函数:
function fjarrett_get_attachment_id_by_url( $url ) {
// Split the $url into two parts with the wp-content directory as the separator
$parsed_url = explode( parse_url( WP_CONTENT_URL, PHP_URL_PATH ), $url );
// Get the host of the current site and the host of the $url, ignoring www
$this_host = str_ireplace( 'www.', '', parse_url( home_url(), PHP_URL_HOST ) );
$file_host = str_ireplace( 'www.', '', parse_url( $url, PHP_URL_HOST ) );
// Return nothing if there aren't any $url parts or if the current host and $url host do not match
if ( ! isset( $parsed_url[1] ) || empty( $parsed_url[1] ) || ( $this_host != $file_host ) ) {
return;
}
// Now we're going to quickly search the DB for any attachment GUID with a partial path match
// Example: /uploads/2013/05/test-image.jpg
global $wpdb;
$attachment = $wpdb->get_col( $wpdb->prepare( "SELECT ID FROM {$wpdb->prefix}posts WHERE guid RLIKE %s;", $parsed_url[1] ) );
// Returns null if no attachment is found
return $attachment[0];
}
感谢弗兰基贾勒特。
然后您可以轻松获得其他尺寸:
$medium_image = wp_get_attachment_image_src( fjarrett_get_attachment_id_by_url($image_link), 'medium');
如果您需要此图片的链接:
$medium_image_link = $medium_image[0];
$html = '<img src="'.$medium_image_link.'" alt="" />';