如果要引用上载目录，请使用https://developer.wordpress.org/reference/functions/wp_upload_dir/

<?php
$upload_dir = wp_upload_dir(); // Array of key => value pairs
/*
    $upload_dir now contains something like the following (if successful)
    Array (
        [path] => C:\\path\\to\\wordpress\\wp-content\\uploads\\2010\\05
        [url] => http://example.com/wp-content/uploads/2010/05
        [subdir] => /2010/05
        [basedir] => C:\\path\\to\\wordpress\\wp-content\\uploads
        [baseurl] => http://example.com/wp-content/uploads
        [error] =>
    )
    // Descriptions
    [path] - base directory and sub directory or full path to upload directory.
    [url] - base url and sub directory or absolute URL to upload directory.
    [subdir] - sub directory if uploads use year/month folders option is on.
    [basedir] - path without subdir.
    [baseurl] - URL path without subdir.
    [error] - set to false.
*/

echo $upload_dir[\'path\'] . \'<br />\';
echo $upload_dir[\'url\'] . \'<br />\';
echo $upload_dir[\'subdir\'] . \'<br />\';
echo $upload_dir[\'basedir\'] . \'<br />\';
echo $upload_dir[\'baseurl\'] . \'<br />\';
echo $upload_dir[\'error\'] . \'<br />\';

$upload_url = ( $upload_dir[\'url\'] );
$upload_url_alt = ( $upload_dir[\'baseurl\'] . $upload_dir[\'subdir\'] );

// Now echo the final result
echo $upload_url . \'<br />\'; // Output - http://example.com/wp-content/uploads/2010/05

// Using year and month based folders, the below will be the same as the line above.
echo $upload_url_alt . \'<br />\'; // Output - http://example.com/wp-content/uploads/2010/05
?>