
如何使用Tailwind CSS快速开发新潮时髦网站
wp_get_attachment_url ( $attachment_id = 0 )
wp_get_attachment_url: 这个函数检索一个附件的URL。它以附件的ID为参数,并返回附件的URL。
检索一个附件的URL。
function wp_get_attachment_url( $attachment_id = 0 ) { global $pagenow; $attachment_id = (int) $attachment_id; $post = get_post( $attachment_id ); if ( ! $post ) { return false; } if ( 'attachment' !== $post->post_type ) { return false; } $url = ''; // Get attached file. $file = get_post_meta( $post->ID, '_wp_attached_file', true ); if ( $file ) { // Get upload directory. $uploads = wp_get_upload_dir(); if ( $uploads && false === $uploads['error'] ) { // Check that the upload base exists in the file location. if ( 0 === strpos( $file, $uploads['basedir'] ) ) { // Replace file location with url location. $url = str_replace( $uploads['basedir'], $uploads['baseurl'], $file ); } elseif ( false !== strpos( $file, 'wp-content/uploads' ) ) { // Get the directory name relative to the basedir (back compat for pre-2.7 uploads). $url = trailingslashit( $uploads['baseurl'] . '/' . _wp_get_attachment_relative_path( $file ) ) . wp_basename( $file ); } else { // It's a newly-uploaded file, therefore $file is relative to the basedir. $url = $uploads['baseurl'] . "/$file"; } } } /* * If any of the above options failed, Fallback on the GUID as used pre-2.7, * not recommended to rely upon this. */ if ( ! $url ) { $url = get_the_guid( $post->ID ); } // On SSL front end, URLs should be HTTPS. if ( is_ssl() && ! is_admin() && 'wp-login.php' !== $pagenow ) { $url = set_url_scheme( $url ); } /** * Filters the attachment URL. * * @since 2.1.0 * * @param string $url URL for the given attachment. * @param int $attachment_id Attachment post ID. */ $url = apply_filters( 'wp_get_attachment_url', $url, $post->ID ); if ( ! $url ) { return false; } return $url; }