ASP.NET

PreRender(){
   // Registering client script block that set page index in hidden
   // and submit the form
}

Render(){
   // Rendering set of links ( <A> ) that will call my javascript function
   // to set page index in hidden and post back the page
}

LoadPostData(){
   // Check hidden variable and return true to raise event
}

RaisePostDataChangedEvent(){
   // Raising PageIndexChanged event
}

First page rendering -> controls are generated dinamically
Postback -> read the controls values and generate new ones
Second page rendering -> show the new controls
 (at this moment, even though the server is rendering a page with completely
  different controls, IsPostBack is true because the webform
  is the same. That's why I cannot use IsPostBack to determine if the
  Page_Load event was fired by a rendering or by a client post)
Postback -> read the controls values and generate new ones
...