Wordpress显示特定类别下的所有帖子

I am trying to display all posts under a child child category. But my code keep rendering Parent category then all the post, then child and all the posts. I keep getting more categories the I want. This sidebar is used in single.php only.

My category structure looks like this.

  • Parent
    • Child 1
      • Child-Child 1.1
      • Child-Child 1.2
    • Child 2
      • Child-Child 2.2

Under Child-child I have posts, how I would like to render it.

<div id="child-child-title">
    <ul>
        <li class="post">title + post meta data</li>
        <li class="post">title + post meta data</li>
        <li class="post">title + post meta data</li>
    </ul>
</div>

Here is what I am working with, and it is rendering every category (either if it's a parent or child) and every post on the site under it.

<?php global $post; $categories = get_the_category();foreach ($categories as $category) : ?>
<h4>&raquo; <?php echo $category->name; ?></h4>
<ul>

<?php
foreach((get_the_category()) as $category) {
    $cat_ids=$cat_ids . $category->cat_ID . ',';
}
$cat_ids=substr($cat_ids, 0, -1);
//----------
?>

<?php $posts = get_posts('numberposts=20&amp;category='. $cat_ids);foreach($posts as $post) : ?>
<a href='<?php the_permalink() ?>'><?php the_title(); ?></a></li><br>
<?php endforeach; ?>
<li><strong><a href="<?php echo get_category_link($category->term_id);?>"><?php echo $category->name; ?> </a></strong></li>
<?php endforeach; ?>
</ul>

Thanks in advance!

Use query posts from a specific category slug

query_posts( array ( 'category_name' => 'my-category-slug', 'posts_per_page' => -1 ) );

For more reference on using this visit Category Function reference

However, for subcategories (or child categories), 'The Category Name' doesn't always work. Rather use 'category-slug' instead.