What if you want Theme Switcher into all your WordPress Themes?
Try this
- Open file “wp-includes\template-functions-general.php” and search for “function wp_meta() {“
- add this code just after "do_action(‘wp_meta’);"
echo "</ul><h2>Themes:</h2><div>";
wp_theme_switcher('dropdown');
echo "</div>";
- save the file, and you’ll get the Theme Switcher on everypage after the meta
You can easily add Theme Switcher to your theme by added
<li>Themes:<?php wp_theme_switcher(); ?></li>
or
<li>Themes:<?php wp_theme_switcher('dropdown'); ?></li>
as described by author