本站中的教程都是成系列的文章，所以为了提高用户体验，我在每篇教程的后面列出当前文章的前3篇文章和后3篇文章，这个可以当成是相关文章吧。
代码乃是我参考wp自带的get_adjacent_post函数修改而来，get_adjacent_post函数是wordpress用来获取上一篇和下一篇文章的基本函数。哎呀文采不好就不废话了函数代码：
函数作用：获取当前文章同分类下的前几篇文章和后几篇文章
参数：$previous为true时获取之前的文章,为false的时候获取之后的文章
$number为获取文章数量
//author:www.shouce.ren
function ashu_get_adjacent_posts( $previous = true, $number = 1 ) {
//global当前文章变量 $post 和数据库操作类wpdb
global $post, $wpdb;
if ( empty( $post ) )
return null;
$current_post_date = $post->post_date;//当前文章的时间
$join = '';
$posts_in_ex_cats_sql = '';
//加入表
$join = " INNER JOIN $wpdb->term_relationships AS tr ON p.ID = tr.object_id INNER JOIN $wpdb->term_taxonomy tt ON tr.term_taxonomy_id = tt.term_taxonomy_id";
//获取当前文章所属分类,可以同属多个分类,如果是自定义的分类法,将category换成对应的分类法即可
$cat_array = wp_get_object_terms($post->ID, 'level', array('fields' => 'ids'));
$join .= " AND tt.taxonomy = 'level' AND tt.term_id IN (" . implode(',', $cat_array) . ")";
//判断时间是大于还是小雨
$op = $previous ? '';
//排序
$order = $previous ? 'DESC' : 'ASC';
$where = $wpdb->prepare("WHERE p.post_date $op %s AND p.post_type = %s AND p.post_status = 'publish' ", $current_post_date, $post->post_type);
$sort = "ORDER BY p.post_date $order LIMIT 0, $number";
$query = "SELECT p.* FROM $wpdb->posts AS p $join $where $sort";
$query_key = 'adjacent_post_' . md5($query);
$result = wp_cache_get($query_key, 'counts');
if ( false !== $result )
return $result;
$result = $wpdb->get_results("SELECT p.* FROM $wpdb->posts AS p $join $where $sort");
if ( null === $result )
$result = '';
wp_cache_set($query_key, $result, 'counts');
return $result;
} 本篇教程之前的几篇教程是
<?php
$preposts = ashu_get_adjacent_posts(true,3);
foreach( $preposts as $postt ){
echo 'ID).'" title="'.$postt->post_title .'">'.$postt->post_title .'';
};
?>
本篇教程之后的几篇教程是
<?php
$nextposts = ashu_get_adjacent_posts(false,3);
foreach( $nextposts as $postt ){
echo 'ID).'" title="'.$postt->post_title .'">'.$postt->post_title .'';
};
?>
将该函数放在主题的functions.php文件中即可，调用该函数的时候会返回一个数组，使用示例：
//author:www.shouce.ren
function ashu_get_adjacent_posts( $previous = true, $number = 1 ) {
//global当前文章变量 $post 和数据库操作类wpdb
global $post, $wpdb;
if ( empty( $post ) )
return null;
$current_post_date = $post->post_date;//当前文章的时间
$join = '';
$posts_in_ex_cats_sql = '';
//加入表
$join = " INNER JOIN $wpdb->term_relationships AS tr ON p.ID = tr.object_id INNER JOIN $wpdb->term_taxonomy tt ON tr.term_taxonomy_id = tt.term_taxonomy_id";
//获取当前文章所属分类,可以同属多个分类,如果是自定义的分类法,将category换成对应的分类法即可
$cat_array = wp_get_object_terms($post->ID, 'level', array('fields' => 'ids'));
$join .= " AND tt.taxonomy = 'level' AND tt.term_id IN (" . implode(',', $cat_array) . ")";
//判断时间是大于还是小雨
$op = $previous ? '';
//排序
$order = $previous ? 'DESC' : 'ASC';
$where = $wpdb->prepare("WHERE p.post_date $op %s AND p.post_type = %s AND p.post_status = 'publish' ", $current_post_date, $post->post_type);
$sort = "ORDER BY p.post_date $order LIMIT 0, $number";
$query = "SELECT p.* FROM $wpdb->posts AS p $join $where $sort";
$query_key = 'adjacent_post_' . md5($query);
$result = wp_cache_get($query_key, 'counts');
if ( false !== $result )
return $result;
$result = $wpdb->get_results("SELECT p.* FROM $wpdb->posts AS p $join $where $sort");
if ( null === $result )
$result = '';
wp_cache_set($query_key, $result, 'counts');
return $result;
} 本篇教程之前的几篇教程是
<?php
$preposts = ashu_get_adjacent_posts(true,3);
foreach( $preposts as $postt ){
echo 'ID).'" title="'.$postt->post_title .'">'.$postt->post_title .'';
};
?>
本篇教程之后的几篇教程是
<?php
$nextposts = ashu_get_adjacent_posts(false,3);
foreach( $nextposts as $postt ){
echo 'ID).'" title="'.$postt->post_title .'">'.$postt->post_title .'';
};
?>
运行一下：
