我刚刚建立了一个主题，在当前页面上寻找一个特色图片，如果找不到特色图片，它将继续通过家谱向后看，直到找到一个。然后它会打印出来。

我写了一个小脚本来实现这一点，但它似乎效率低下。必须有更好的方法来做这件事。可能是我错过的WP功能？这是代码，请仔细查看。

//get the ancestors
$familyTree = get_ancestors($post->ID,\'page\');
array_unshift( $familyTree, $post->ID ); //add the current page to the begining of the list

//loop through the family tree until you find a result or exhaust the array
$featuredImageFound = false;
$i = 0;
while (!$featuredImageFound && ($i < count($familyTree)) ) {
    if(has_post_thumbnail( $familyTree[$i] )){
        $featuredImage = get_the_post_thumbnail($familyTree[$i], \'full\');
    $featuredImageFound = true;
}
$i++;
}

// if the page has a featured image then show it
echo ( $featuredImageFound ? $featuredImage : "" );