Adding a custom field to conditionally display last modified date:

您可以使用帖子的内置自定义字段元框。通常它在默认情况下是隐藏的，因此您必须在“屏幕选项”中启用它，并选中“自定义字段”框，如下所示：

如果使用新的块编辑器，可以通过转到Edit Post Screen > Click the three dots button on the top right corner > Settings > Advanced Panels.

现在，添加一个新的自定义字段，我们将其称为show_last_modified 并将其设置为true。

Displaying the last modified date:

功能the_modified_date() 将为您提供上次修改帖子的日期。

要显示它，似乎必须覆盖mh_magazine_post_meta() 作用

function mh_magazine_post_meta() {
    $mh_magazine_options = mh_magazine_theme_options();
    if ($mh_magazine_options[\'post_meta_date\'] === \'enable\' || $mh_magazine_options[\'post_meta_author\'] === \'enable\' && in_the_loop() || $mh_magazine_options[\'post_meta_cat\'] === \'enable\' && in_the_loop() && is_singular() || $mh_magazine_options[\'post_meta_comments\'] === \'enable\') {
        echo \'<div class="mh-meta entry-meta">\' . "\\n";
            if ($mh_magazine_options[\'post_meta_date\'] === \'enable\') {
                echo \'<span class="entry-meta-date updated"><i class="fa fa-clock-o"></i><a href="\' . esc_url(get_month_link(get_the_time(\'Y\'), get_the_time(\'m\'))) . \'">\' . get_the_date() . \'</a></span>\' . "\\n";
                // Custom code

                if(!empty(get_post_meta(get_the_ID(), \'show_last_modified\', true)){
                   echo \'Last modified date:\' . the_modified_date();
                }

                //
            }
            if ($mh_magazine_options[\'post_meta_author\'] === \'enable\' && in_the_loop()) {
                echo \'<span class="entry-meta-author author vcard"><i class="fa fa-user"></i><a class="fn" href="\' . esc_url(get_author_posts_url(get_the_author_meta(\'ID\'))) . \'">\' . esc_html(get_the_author()) . \'</a></span>\' . "\\n";
            }
            if ($mh_magazine_options[\'post_meta_cat\'] === \'enable\' && in_the_loop() && is_singular()) {
                echo \'<span class="entry-meta-categories"><i class="fa fa-folder-open-o"></i>\' . get_the_category_list(\', \', \'\') . \'</span>\' . "\\n";
            }
            if ($mh_magazine_options[\'post_meta_comments\'] === \'enable\') {
                echo \'<span class="entry-meta-comments"><i class="fa fa-comment-o"></i>\';
                    mh_magazine_comment_count();
                echo \'</span>\' . "\\n";
            }
        echo \'</div>\' . "\\n";
    }
}

add_action(\'mh_post_header\', \'mh_magazine_post_meta\');

将上述代码放在子主题上，并自定义标记以满足您的需要。