在Wordpress中打开父页/子页时显示子页

Posted 2021-02-25

function navigation() {
	global $wpdb, $post;
 
	$query = $wpdb->get_results("SELECT ID, post_title FROM {$wpdb->prefix}posts WHERE post_status = 'publish' AND post_type = 'page' AND post_parent = 0");
 
	echo '<div id="nav">';
	echo '<ul>';
 
	foreach ($query as $obj) {
 
		echo '<li><a href="'.get_bloginfo('wpurl').'/?page_id='.$obj->ID.'">'.$obj->post_title.'</a></li>';
 
		$sub_query = $wpdb->get_results("SELECT ID, post_title, post_parent FROM {$wpdb->prefix}posts WHERE post_status = 'publish' AND post_type = 'page' AND post_parent = {$obj->ID}");
 
		foreach($sub_query as $sub_obj) {
			if($post->ID == $sub_obj->post_parent)
  				echo '<li><a href="'.get_bloginfo('wpurl').'/?page_id='.$sub_obj->ID.'" class="subpage">'.$sub_obj->post_title.'</a></li>';
 
  			if($post->post_parent == $sub_obj->post_parent)
  				echo '<li><a href="'.get_bloginfo('wpurl').'/?page_id='.$sub_obj->ID.'" class="subpage">'.$sub_obj->post_title.'</a></li>';
  		}	
 
 
  	}
 
	echo '</ul>';
	echo '</div>';
}