wp_get_attachment_url() | 获取WordPress附件/图片的链接/url

函数

wp_get_attachment_url( $id );

描述

该WordPress函数可获取附件的url

参数

返回值

返回附件文件的完整 URI，如果获取失败，返回 false。

划重点

可以通过使用 wp_get_attachment_url_filter 修改函数的输出。

此函数将不会 urlencode 获取到的 url，如果附件文件名有不合法的字符串，我们需要使用编码输出的内容以获取一个正确的url。

如果需要一个附件页面的 URI ，而不是附件文件，我们可以使用 get_attachment_link 函数。

实例

获取附件id为2048的附件链接

echo wp_get_attachment_url( 2048 );

修改记录

WordPress 2.1.0

源文件

wp-includes/post.php

function wp_get_attachment_url( $attachment_id = 0 ) {
    $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' !== $GLOBALS['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;
}