我正在尝试根据自定义字段设置帖子的特色图像。有不同类型的帖子，因此应根据填写的自定义字段设置特色图像。
以下是我目前所编辑的内容：
//Set post thumbnail based on various conditions
if (get_post_meta($post_id, \'featured_image\', true)) {
$attachment_id = get_post_meta($post_id, \'featured_image\', true);
} elseif (get_post_meta($post_id, \'upload_single_image\', true)) {
$attachment_id = get_post_meta($post_id, \'upload_single_image\', true);
} elseif (get_post_meta($post_id, \'create_gallery\', false)) {
$gallery = get_post_meta($post_id, \'create_gallery\', false);//get the full gallery
$attachment_id = $gallery[0][\'upload_image\']; //Get image from first row
}
前两个条件有效，但第三个条件（创建库）无效。我原以为获取db表的第一行，然后调用自定义元数据的名称就可以了，但不起作用。
有人看到我可能做错了什么吗？
SO网友:tfrommen
您必须设置$single paramter of get_post_meta 设置为false（或不设置）以获取数组。
以下是加速版：
if ($attachment_id = get_post_meta($post_id, \'featured_image\', true)) :
elseif ($attachment_id = get_post_meta($post_id, \'upload_single_image\', true)) :
elseif ($attachment_id = get_post_meta($post_id, \'create_gallery\', false)) :
$attachment_id = $attachment_id[0][\'upload_image\'];
endif;
Note: 我没有测试这个。
<小时>// EDIT
以下是ACF功能的代码：
if ($attachment_id = get_post_meta($post_id, \'featured_image\', true)) :
elseif ($attachment_id = get_post_meta($post_id, \'upload_single_image\', true)) :
elseif ($gallery = get_field(\'create_gallery\', $post_id)) :
$attachment_id = $gallery[0][\'upload_image\'];
endif;
SO网友:Eckstein
通过使用ACF的自定义函数而不是wp的元函数，它得以工作。
最终工作结果：
//Set post thumbnail based on various conditions
if (get_post_meta($post_id, \'featured_image\', true)) {
$attachment_id = get_post_meta($post_id, \'featured_image\', true);
} elseif (get_post_meta($post_id, \'upload_single_image\', true)) {
$attachment_id = get_post_meta($post_id, \'upload_single_image\', true);
} elseif (get_field(\'create_gallery\', $post_id)) {
$gallery = get_field(\'create_gallery\', $post_id);//get the full gallery
$attachment_id = $gallery[0][\'upload_image\']; //Get image from first row
}
