在此处找到挂钩：http://hookr.io/actions/widgets_admin_page/

// define the widgets_admin_page callback 
function action_widgets_admin_page(  ) { 
    // make action magic happen here... 
}; 

// add the action 
add_action( \'widgets_admin_page\', \'action_widgets_admin_page\', 10, 0 );