The problem of calling another page when opening the html page_html/css_WEB-ITnose

html hyperlink html calls html event

For example, there is a hyperlink in b.php click
like this browser Click and tap to go back and load this page.
I want a.php to be loaded first as soon as b.php is run. In my memory, it seems to use the onload event, but after trying it, it doesn't seem to work. I hope you can give me some advice.

Reply to the discussion (solution)

Use ajax to preload the content of a.php and save it into a global variable, and then operate the global variable after clicking

Use ajax to get it and then open it. The premise is that the a.php browser can cache
or the iframe should be hidden first and displayed when needed. It must be embedded in the b page in advance