accessing control on page A.ASPX from a WEBUSERCONTROL.ASCX

How can I access a control on page a.aspx from a webusercontrol.ascx

• I do not know the technical term used to describe this, if any,

• the webusercontrol.ascx page contains a button.

  • onclick of the button, placeholder on main page must display the "required content".

• if this were on the same page no problem.开发者_JAVA百科

but how to access across pages?

Expose an event on your ASCX control, subscribe an event handler method on the ASPX page to the event on that page's instance of that control, implement the method to make the required changes to the parent page.