给WordPress相关文章显示缩略图

　　为了增加用户体验和阅读深度，很多朋友喜欢为自己的博客添加相关文章功能，有些是纯文字的，而有些则是带缩略图的，今天这里我就简单说下带缩略图的相关文章的实现方法。
　　将以下代码加入 single.php 文件中想要显示带缩略图的相关文章处：

<div id=”related-posts”>
<div class=”caption”>带缩略图的相关文章：</div>
<div class=”related” class=”clearfix”>
<ul>
<?php
$post_num = 5; // 设定数量.
$exclude_id = $post->ID; // 單獨使用要開此行
$posttags = get_the_tags(); $i = 0;
if ( $posttags ) {
$tags = ”; foreach ( $posttags as $tag ) $tags .= $tag->term_id . ‘,’;
$args = array(
‘post_status’ => ‘publish’,
‘tag__in’ => explode(‘,’, $tags), // 只選 tags 的文章.
‘post__not_in’ => explode(‘,’, $exclude_id), // 排除已出現過的文章.
‘caller_get_posts’ => 1,
‘orderby’ => ‘comment_date’, // 依評論日期排序.
‘posts_per_page’ => $post_num,
);
query_posts($args);
while( have_posts() ) { the_post();
?>
<li><a href=”<?php echo the_permalink(); ?>” title=”<?php the_title(); ?>” ><img src=”<?php if ( get_post_meta($post->ID, ‘thumbnail1’, true) ) { echo get_post_meta($post->ID, ‘thumbnail1’, true);}
elseif ( has_post_thumbnail() ){$thumbnail1_url = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), ‘thumbnail1’);echo $thumbnail1_url[0];}else{echo catch_first_image();} ?>” alt=”<?php the_title(); ?>” width=”120″ height=”120″ ></a>
<a href=”<?php echo the_permalink(); ?>” ><?php the_title(); ?></a></li>
<?php
$exclude_id .= ‘,’ . $post->ID; $i ++;
} wp_reset_query();
}
if ( $i < $post_num ) { // 如果 tags 文章數量不足, 再取 category 補足.
$cats = ”; foreach ( get_the_category() as $cat ) $cats .= $cat->cat_ID . ‘,’;
$args = array(
‘category__in’ => explode(‘,’, $cats), // 只選 category 的文章.
‘post__not_in’ => explode(‘,’, $exclude_id),
‘caller_get_posts’ => 1,
‘orderby’ => ‘comment_date’,
‘posts_per_page’ => $post_num – $i,
);
query_posts($args);
while( have_posts() ) { the_post();
?>
<li><a href=”<?php echo the_permalink(); ?>” title=”<?php the_title(); ?>” ><img src=”<?php if ( get_post_meta($post->ID, ‘thumbnail1’, true) ) { echo get_post_meta($post->ID, ‘thumbnail1’, true);}
elseif ( has_post_thumbnail() ){$thumbnail1_url = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), ‘thumbnail1’);echo $thumbnail1_url[0];}else{echo catch_first_image();} ?>” alt=”<?php the_title(); ?>” width=”120″ height=”120″ ></a>
<a href=”<?php echo the_permalink(); ?>” ><?php the_title(); ?></a></li>
<?php
$i++;
} wp_reset_query();
}
if ( $i == 0 ) echo ‘<li>没有相关文章!</li>’;
?>
</ul>
</div>
</div>
<!– release post end –>

　　根据自己博客样式修改一下 CSS 代码：

/** related post thumbnail **/
#related-posts{border-radius:5px;border-top:3px #dfdfdf solid;background:#fff;clear:both;}
.caption{color:#0C0C0B;font-size: 14px;font-weight:bold;padding-top: 10px;margin-bottom: 10px;margin-left:10px;}
.related {white-space:normal;margin:0 auto;overflow: hidden;border-left: 1px solid #DFDFDF;margin-left:20px;}
.related li{float: left;width: 120px;height:180px;list-style:none;border-right:1px solid #dfdfdf;padding:4px;_padding:2px;text-align: left;}
.related a{float: left;width: 126px;text-overflow: ellipsis;-o-text-overflow: ellipsis;}
.related a:hover{white-space: normal;}
.related li:hover{background:#F6F6F6;}
.related img{height:120px;width:120px;border:0;padding:0;}

　　也可以把上面第一步中的 php 函数代码放在单独一个文件中，如 likeposts.php，然后在想要调用的页面添加调用代码：

<?php include(‘includes/likeposts.php’);?>