注册一个小部件，当the_post 第二次调用操作：

add_action( \'wp_loaded\', \'wpse_80202_register_banner_widget\' );
function wpse_80202_register_banner_widget()
{
    // used on the first page of main loop only
    register_sidebar(
        array (
            \'name\'          => \'Banner front-page \',
            \'id\'            => \'frontpage_banner\',
            \'before_widget\' => \'<div class="frontpage-banner">\',
            \'after_widget\'  => \'</div>\'
        )
    );
}

add_action( \'loop_start\', \'wpse_80202_show_banner_widget\' );

function wpse_80202_show_banner_widget()
{
    static $count = 0;
    if ( ! is_front_page() )
        return;

    if ( \'loop_start\' === current_filter() )
    {
        add_action( \'the_post\', __FUNCTION__ );
        return;
    }

    $count += 1;

    if ( 2 === $count )
    {
        dynamic_sidebar( \'frontpage_banner\' );
        remove_action( \'the_post\', __FUNCTION__ );
    }
}

此代码的另一个变体如下：Add Adsense code in index.php