不使用插件让WordPress按分类自动调用相关文章

在WordPress文章后面列出相关文章，可以方便读者浏览更多相关的内容，通过下面的代码即可实现自动显示相关文章（按分类）。

首先，将下面的代码粘贴到你的主题functions.php文件中：

// "More from This Category" list by Barış Ünver @ Wptuts+  
function wptuts_more_from_cat( $title = "More From This Category:" ) {  
    global $post;  
    // We should get the first category of the post  
    $categories = get_the_category( $post->ID );  
    $first_cat = $categories[0]->cat_ID;  
    // Let's start the $output by displaying the title and opening the <ul>  
    $output = '<div id="more-from-cat"><h3>' . $title . '</h3>';  
    // The arguments of the post list!  
    $args = array(  
        // It should be in the first category of our post:  
        'category__in' => array( $first_cat ),  
        // Our post should NOT be in the list:  
        'post__not_in' => array( $post->ID ),  
        // ...And it should fetch 5 posts - you can change this number if you like:  
        'posts_per_page' => 5  
    );  
    // The get_posts() function  
    $posts = get_posts( $args );  
    if( $posts ) {  
        $output .= '<ul>';  
        // Let's start the loop!  
        foreach( $posts as $post ) {  
            setup_postdata( $post );  
            $post_title = get_the_title();  
            $permalink = get_permalink();  
            $output .= '<li><a href="'%20.%20$permalink%20.%20'" title="' . esc_attr( $post_title ) . '">' . $post_title . '</a></li>';  
        }  
        $output .= '</ul>';  
    } else {  
        // If there are no posts, we should return something, too!  
        $output .= '<p>Sorry, this category has just one post and you just read it!</p>';  
    }  
    // Let's close the <div> and return the $output:  
    $output .= '</div>';  
    return $output;  
}  

之后，打开single.php文件，在适当位置添加调用函数：

<?php echo wptuts_more_from_cat( 'More From This Category:' ); ?>