Thank you for your answer, but I still don’t understand. I opened the subpage with <iframe> </ iframe> on the parent page. Even if each page introduces a theme file, how to use the theme of the parent page in the case of cross-domain. My idea is: set the theme information on the parent page and put it into localStorage, then the subpage gets this information and sets the theme, then there will be problems, when you open the subpage, you can successfully set the theme, but if you When you open a subpage first and then switch the theme of the parent page, the subpages do not switch the theme together. You need to reinitialize the theme properties of all components of the subpage. The official demo does not seem to be implemented this way. I need a more detailed answer, preferably with an example. Thank you.