如何返回頁面id在自定義漫遊器

Question

我正在嘗試使用自定義漫步者使頁面縮略圖返回自定義導航菜單項。我的完整步行者低於，看起來這部分

$thumbnail = ''; 
if($id = has_post_thumbnail((int)$item->object_id)) { 
$thumbnail = get_the_post_thumbnail($id); 
} 

不拉動頁面ID，所以我沒有縮略圖。任何幫助表示讚賞

/* 
* Create HTML list of nav menu items. 
* Replacement for the native Walker, using the description. 
* 
* @see http://wordpress.stackexchange.com/q/14037/ 
* @author toscho, http://toscho.de 
*/ 
class Thumbnail_Walker extends Walker_Nav_Menu 
{ 
/** 
* Start the element output. 
* 
* @param string $output Passed by reference. Used to append additional content. 
* @param object $item Menu item data object. 
* @param int $depth  Depth of menu item. May be used for padding. 
* @param array $args Additional strings. 
* @return void 
*/ 
function start_el(&$output, $item, $depth, $args) 
{ 
$classes  = empty ($item->classes) ? array() : (array) $item->classes; 

$class_names = join(
    ' ' 
, apply_filters(
     'nav_menu_css_class' 
    , array_filter($classes), $item 
    ) 
); 

! empty ($class_names) 
    and $class_names = ' class="'. esc_attr($class_names) . '"'; 

$output .= "<li id='menu-item-$item->ID' $class_names>"; 

$attributes = ''; 

! empty($item->attr_title) 
    and $attributes .= ' title="' . esc_attr($item->attr_title) .'"'; 
! empty($item->target) 
    and $attributes .= ' target="' . esc_attr($item->target ) .'"'; 
! empty($item->xfn) 
    and $attributes .= ' rel="' . esc_attr($item->xfn  ) .'"'; 
! empty($item->url) 
    and $attributes .= ' href="' . esc_attr($item->url  ) .'"'; 

// insert thumbnail 
// you may change this 
$thumbnail = ''; 
if($id = has_post_thumbnail((int)$item->object_id)) { 
    $thumbnail = get_the_post_thumbnail($id); 
} 

$title = apply_filters('the_title', $item->title, $item->ID); 

$item_output = $args->before 
    . "<a $attributes>" 
    . $args->link_before 
    . $title 
    . '</a> ' 
    . $args->link_after 
    . $thumbnail 
    . $args->after; 

// Since $output is called by reference we don't need to return anything. 
$output .= apply_filters(
    'walker_nav_menu_start_el' 
, $item_output 
, $item 
, $depth 
, $args 
); 
} 
} 

Answer 1

根據http://phpdoc.wordpress.org 看起來你可以$args後$id參數添加到您的start_el功能，像這樣：

function start_el(&$output, $item, $depth, $args, $id)