wordpress二次开发技巧之functions.php篇

wordpress二次开发中对于functions.php的制作是非常多的，今天我们来分享关于wordpress二次开发技巧之functions.php的制作，希望大家可以喜欢！

下面根据需求，对各种能实现进行简单介绍。

先对functions.php文件进行介绍，通过代码实现各功能。

1. widgets sidebar 侧边栏小工具

wordpress二次开发技巧之functions.php篇

01 /** widgets sidebar 侧边栏小工具*/
02 if( function_exists('register_sidebar'class="crayon-sy">) ) {
03   register_sidebar(array(
04     'name' class="crayon-o">=> 'First_sidebar'class="crayon-sy">,
05     'before_widget' class="crayon-o">=> ''class="crayon-sy">,
06     'after_widget' class="crayon-o">=> ''class="crayon-sy">,
07     'before_title' class="crayon-o">=> ''class="crayon-sy">,
08     'after_title' class="crayon-o">=> ''
09   ));
10   register_sidebar(array(
11     'name' class="crayon-o">=> 'Second_sidebar'class="crayon-sy">,
12     'before_widget' class="crayon-o">=> ''class="crayon-sy">,
13     'after_widget' class="crayon-o">=> ''class="crayon-sy">,
14     'before_title' class="crayon-o">=> ''class="crayon-sy">,
15     'after_title' class="crayon-o">=> ''
16   ));
17   register_sidebar(array(
18     'name' class="crayon-o">=> 'Third_sidebar'class="crayon-sy">,
19     'before_widget' class="crayon-o">=> ''class="crayon-sy">,
20     'after_widget' class="crayon-o">=> ''class="crayon-sy">,
21     'before_title' class="crayon-o">=> ''class="crayon-sy">,
22     'after_title' class="crayon-o">=> ''
23   ));
24   register_sidebar(array(
25     'name' class="crayon-o">=> 'Fourth_sidebar'class="crayon-sy">,
26     'before_widget' class="crayon-o">=> ''class="crayon-sy">,
27     'after_widget' class="crayon-o">=> ''class="crayon-sy">,
28     'before_title' class="crayon-o">=> ''class="crayon-sy">,
29     'after_title' class="crayon-o">=> ''
30   ));
31 }
32
33 register_nav_menus(array("primary" => "Primary Navigation"));

2. 后台支持自定义菜单

wordpress二次开发技巧之functions.php篇

01 /*nav  后台自定义菜单*/
02 if(function_exists('register_nav_menus'class="crayon-sy">)){
03   register_nav_menus(
04     array(
05     'header-menu' class="crayon-o">=> __( '导航自定义菜单' class="crayon-sy">),
06     'footer-menu' class="crayon-o">=> __( '页角自定义菜单' class="crayon-sy">),
07     'sider-menu' class="crayon-o">=> __('侧边栏菜单'class="crayon-sy">),
08     'primary' class="crayon-o">=> __( 'Primary Navigation'class="crayon-sy">, 'lee' class="crayon-sy">),
09     )
10   );
11 }

输出菜单，在如header.php插入显示菜单的代码

1 array( 'container' class="crayon-o">=> '' class="crayon-sy">) ); ?>

 

3. 面包屑导航

01 // 面包屑导航注册代码
02 function wheatv_breadcrumbs() {
03   $delimiter = '>'class="crayon-sy">;
04   $name = '首页'class="crayon-sy">; //text for the 'Home' link
05   $currentBefore = ''class="crayon-sy">;
06   $currentAfter = ''class="crayon-sy">;
07
08   if ( !is_home() && !is_front_page() || is_paged() ) {
09
10   echo ''class="crayon-sy">;
11   global $post;
12   // $home = get_bloginfo('url');
13   $home = get_option('home'class="crayon-sy">);
14   echo 'class="crayon-sy">.$home.'" >'class="crayon-sy">. $name . ' ' class="crayon-sy">. $delimiter . ' 'class="crayon-sy">;
15
16   if ( is_category() ) {
17     global $wp_query;
18     $cat_obj = $wp_query->get_queried_object();
19     $thisCat = $cat_obj->term_id;
20     $thisCat = get_category($thisCat);
21     $parentCat = get_category($thisCat->parent);
22     if ($thisCat->parent != 0) echo(get_category_parents($parentCat, TRUE, ' ' class="crayon-sy">. $delimiter . ' 'class="crayon-sy">));
23       echo $currentBefore . ''class="crayon-sy">;
24       single_cat_title();
25       echo '' class="crayon-sy">. $currentAfter;
26
27     } elseif ( is_day() ) {
28       echo '' class="crayon-sy">. get_the_time('Y'class="crayon-sy">) .' ' class="crayon-sy">. $delimiter . ' 'class="crayon-sy">;
29       echo '' class="crayon-sy">. get_the_time('F'class="crayon-sy">) .' ' class="crayon-sy">. $delimiter . ' 'class="crayon-sy">;
30       echo $currentBefore . get_the_time('d'class="crayon-sy">) . $currentAfter;
31
32     } elseif ( is_month() ) {
33       echo '' class="crayon-sy">. get_the_time('Y'class="crayon-sy">) .' ' class="crayon-sy">. $delimiter . ' 'class="crayon-sy">;
34       echo $currentBefore . get_the_time('F'class="crayon-sy">) . $currentAfter;
35
36     } elseif ( is_year() ) {
37       echo $currentBefore . get_the_time('Y'class="crayon-sy">) . $currentAfter;
38
39     } elseif ( is_single() ) {
40       $cat = get_the_category(); $cat = $cat[0];
41       echo get_category_parents($cat, TRUE, ' ' class="crayon-sy">. $delimiter . ' 'class="crayon-sy">);
42       echo $currentBefore;
43       the_title();
44       echo $currentAfter;
45
46     } elseif ( is_page() && !$post->post_parent ) {
47       echo $currentBefore;
48       the_title();
49       echo $currentAfter;
50
51     } elseif ( is_page() && $post->post_parent ) {
52       $parent_id = $post->post_parent;
53       $breadcrumbs = array();
54       while ($parent_id) {
55         $page = get_page($parent_id);
56         $breadcrumbs[] = '' class="crayon-sy">. get_the_title($page->ID) .''class="crayon-sy">;
57         $parent_id = $page->post_parent;
58       }
59       $breadcrumbs = array_reverse($breadcrumbs);
60       foreach ($breadcrumbs as $crumb) echo $crumb . ' ' class="crayon-sy">.$delimiter . ' 'class="crayon-sy">;
61       echo $currentBefore;
62       the_title();
63       echo $currentAfter;
64
65     } elseif ( is_search() ) {
66       echo $currentBefore . '搜索结果' class="crayon-sy">. get_search_query() . '' class="crayon-sy">. $currentAfter;
67
68     } elseif ( is_tag() ) {
69       echo $currentBefore . '搜索标签： 'class="crayon-sy">;
70       single_tag_title();
71       echo '' class="crayon-sy">. $currentAfter;
72
73     } elseif ( is_author() ) {
74       global $author;
75       $userdata = get_userdata($author);
76       echo $currentBefore . 'Articles posted by ' class="crayon-sy">. $userdata->display_name . $currentAfter;
77
78     } elseif ( is_404() ) {
79       echo $currentBefore . 'Error 404' class="crayon-sy">. $currentAfter;
80   }
81
82   if ( get_query_var('paged'class="crayon-sy">) ) {
83     if ( is_category() || is_day() || is_month() || is_year() || is_search() || is_tag() || is_author() ) echo ' ('class="crayon-sy">;
84       echo __('第'class="crayon-sy">) . '' class="crayon-sy">. get_query_var('paged'class="crayon-sy">) . '页'class="crayon-sy">;
85     if ( is_category() || is_day() || is_month() || is_year() || is_search() || is_tag() || is_author() ) echo ')'class="crayon-sy">;
86   }
87   echo ''class="crayon-sy">;
88   }
89 }

 

显示面包屑导航（category.php或single.php等）

1

 

4.  文章访问量（点击数）

wordpress二次开发技巧之functions.php篇

01 //文章点击数
02 function getPostViews($postID){
03     $count_key = 'post_views_count'class="crayon-sy">;
04     $count = get_post_meta($postID, $count_key, true);
05     if($count==''class="crayon-sy">){
06         delete_post_meta($postID, $count_key);
07         add_post_meta($postID, $count_key, '0'class="crayon-sy">);
08         return "0";
09     }
10     return $count;
11 }
12 function setPostViews($postID) {
13     $count_key = 'post_views_count'class="crayon-sy">;
14     $count = get_post_meta($postID, $count_key, true);
15     if($count==''class="crayon-sy">){
16         $count = 0;
17         delete_post_meta($postID, $count_key);
18         add_post_meta($postID, $count_key, '0'class="crayon-sy">);
19     }else{
20         $count++;
21         update_post_meta($postID, $count_key, $count);
22     }
23 }

显示点击量（如category.php或single.php）

1 echo getPostViews(get_the_ID()); ?>

 

5. 文章中所有链接新窗口中打开

 

1 //为文章中所有链接添加target="_blank"属性
2 function autoblank($content) {
3     $content = preg_replace("//", "_blank">", $content);
4     return $content;
5 }
6 add_filter('the_content'class="crayon-sy">, 'autoblank'class="crayon-sy">);

6. 清除wp自带无用头部信息

01 //清除头部信息
02 //remove_action( 'wp_head', 'wp_enqueue_scripts', 1 );
03 remove_action( 'wp_head'class="crayon-sy">, 'feed_links'class="crayon-sy">, 2 );
04 remove_action( 'wp_head'class="crayon-sy">, 'feed_links_extra'class="crayon-sy">, 3 );
05 remove_action( 'wp_head'class="crayon-sy">, 'rsd_link' class="crayon-sy">);
06 remove_action( 'wp_head'class="crayon-sy">, 'wlwmanifest_link' class="crayon-sy">);
07 remove_action( 'wp_head'class="crayon-sy">, 'index_rel_link' class="crayon-sy">);
08 remove_action( 'wp_head'class="crayon-sy">, 'parent_post_rel_link'class="crayon-sy">, 10, 0 );
09 remove_action( 'wp_head'class="crayon-sy">, 'start_post_rel_link'class="crayon-sy">, 10, 0 );
10 remove_action( 'wp_head'class="crayon-sy">, 'adjacent_posts_rel_link_wp_head'class="crayon-sy">, 10, 0 );
11 //remove_action( 'wp_head', 'locale_stylesheet' );
12 remove_action( 'publish_future_post'class="crayon-sy">, 'check_and_publish_future_post'class="crayon-sy">, 10, 1 );
13 //remove_action( 'wp_head', 'noindex', 1 );
14 //remove_action( 'wp_head', 'wp_print_styles', 8 );
15 //remove_action( 'wp_head', 'wp_print_head_scripts', 9 );
16 remove_action( 'wp_head'class="crayon-sy">, 'wp_generator' class="crayon-sy">);
17 //remove_action( 'wp_head', 'rel_canonical' );
18 remove_action( 'wp_footer'class="crayon-sy">, 'wp_print_footer_scripts' class="crayon-sy">);
19 remove_action( 'wp_head'class="crayon-sy">, 'wp_shortlink_wp_head'class="crayon-sy">, 10, 0 );
20 remove_action( 'template_redirect'class="crayon-sy">, 'wp_shortlink_header'class="crayon-sy">, 11, 0 );
21 add_action('widgets_init'class="crayon-sy">, 'my_remove_recent_comments_style'class="crayon-sy">);
22 function my_remove_recent_comments_style() {
23 global $wp_widget_factory;
24 remove_action('wp_head'class="crayon-sy">, array($wp_widget_factory->widgets['WP_Widget_Recent_Comments'class="crayon-sy">], 'recent_comments_style'class="crayon-sy">));
25 }

7. 自动保存和文章修订功能

wordpress二次开发技巧之functions.php篇

1 //自动保存和文章修订功能
2 define('AUTOSAVE_INTERVAL'class="crayon-sy">, 120 );  // 设置自动保存间隔，单位是秒，默认60
3 define('WP_POST_REVISIONS'class="crayon-sy">, false); // 如果不禁用自动修订，最多允许保存的版本数，3表示最多保存3个修订版

8. 彩色静态标签云

wordpress二次开发技巧之functions.php篇

01 // 彩色静态标签云 Color Tag Cloud
02 function colorCloud($text) {
03   $text = preg_replace_callback('||i'class="crayon-sy">, 'colorCloudCallback'class="crayon-sy">, $text);
04   return $text;
05 }
06 function colorCloudCallback($matches) {
07   $text = $matches[1];
08   $color = dechex(rand(0,16777215));
09   $pattern = '/style=('|")(.*)('|")/i'class="crayon-sy">;
10   $text = preg_replace($pattern, "style="color:#{$color};$2;"", $text);
11   return "";
12 }
13 add_filter('wp_tag_cloud'class="crayon-sy">, 'colorCloud'class="crayon-sy">, 1);

输出标签

1 'smallest=10&largest=14&number=32&order=RAND'class="crayon-sy">) ?>

9. 搜索结果关键词高亮显示

具体实现，再另写文章介绍，后续可通过搜索找到。

wordpress二次开发技巧之functions.php篇

01 // 搜索结果关键词高亮显示
02 function lee_set_query() {
03   $query  = attribute_escape(get_search_query());
04   if(strlen($query) > 0){
05     echo '
06       <code class="Brush string">"text/javascript"</code><code class="Brush plain">></code></td> </tr> </tbody> </table> </div> <div class="line alt1"> <table> <tbody> <tr> <td class="number"><code>07</code></td> <td class="content"><code class="spaces">        </code><code class="Brush keyword">var</code> <code class="Brush plain">lee_query  = </code><code class="Brush string">"'.$query.'"</code><code class="Brush plain">;</code></td> </tr> </tbody> </table> </div> <div class="line alt2"> <table> <tbody> <tr> <td class="number"><code>08</code></td> <td class="content"><code class="spaces">      </code><code class="Brush plain">
09     'class="crayon-sy">;
10   }
11 }
12 function lee_init_jquery() {
13 wp_enqueue_script('jquery'class="crayon-sy">);
14 }
15 add_action('init'class="crayon-sy">, 'lee_init_jquery'class="crayon-sy">);
16 add_action('wp_print_scripts'class="crayon-sy">, 'lee_set_query'class="crayon-sy">);

10. 自定义登录界面

在不更改html的情况下，可通过引入样式文件，自定义登录界面。

wordpress二次开发技巧之functions.php篇

01 // 自定义登录界面
02 function custom_login(){
03     echo 'class="crayon-sy">. get_bloginfo('template_directory'crayon-sy">) . '/css/login.css" />'class="crayon-sy">;
04 }
05 add_action('login_head'class="crayon-sy">, 'custom_login'class="crayon-sy">);
06
07 function login_headerurl($url) {
08     return get_bloginfo('url'class="crayon-sy">);
09 }
10 add_filter('login_headerurl'class="crayon-sy">, 'login_headerurl'class="crayon-sy">);
11
12 function login_headertitle($title){
13     return __('轩枫阁'class="crayon-sy">);
14 }
15 add_filter('login_headertitle'class="crayon-sy">, 'login_headertitle'class="crayon-sy">);

11. 获得当前文章的位置

wordpress二次开发技巧之functions.php篇

wordpress二次开发技巧之functions.php篇

01 // 当前文章
02 function num_Pcurrent_post() {
03   global $wpdb;
04   $postid = get_the_ID();//获取当前文章的ID
05   $getpost = get_post($postid);
06   $daysago = $getpost->post_date;//获取当前文章的发布时间
07   $today = gmdate('Y-m-d H:i:s'class="crayon-sy">, time() + 3600 * 8);//获取当前服务器的时间
08   $count_posts = wp_count_posts();
09   $num_all_posts = $count_posts->publish;//总的文章数量
10   $result = $wpdb->get_results("SELECT ID FROM $wpdb->posts WHERE post_date BETWEEN '$daysago' AND '$today' AND post_status='publish' AND post_type='post' ORDER BY post_date DESC ");
11   foreach ($result as $Item) {
12   $post_ID[] = $Item->ID;
13   }
14   $num_current_post = count($post_ID)-1;//当前文章发布以前的文章数量总数
15   $output .= $num_current_post.'/'class="crayon-sy">.$num_all_posts;
16   echo $output;
17 }
18 function num_Ncurrent_post() {
19   global $wpdb;
20   $postid = get_the_ID();//获取当前文章的ID
21   $getpost = get_post($postid);
22   $daysago = $getpost->post_date;//获取当前文章的发布时间
23   $today = gmdate('Y-m-d H:i:s'class="crayon-sy">, time() + 3600 * 8);//获取当前服务器的时间
24   $count_posts = wp_count_posts();
25   $num_all_posts = $count_posts->publish;//总的文章数量
26   $result = $wpdb->get_results("SELECT ID FROM $wpdb->posts WHERE post_date BETWEEN '$daysago' AND '$today' AND post_status='publish' AND post_type='post' ORDER BY post_date DESC ");
27   foreach ($result as $Item) {
28   $post_ID[] = $Item->ID;
29   }
30   $num_current_post = count($post_ID)+1;//当前文章发布以前的文章数量总数
31   $output .= $num_current_post.'/'class="crayon-sy">.$num_all_posts;
32   echo $output;
33 }

显示上下篇及位置，在single.php

1 if (get_next_post()) { echo  next_post_link('%link'class="crayon-sy">,__( '上一篇'class="crayon-sy">, 'lee'class="crayon-sy">),$in_same_cat = false,$excluded_categories = '11'class="crayon-sy">);  } else { echo '已最新'class="crayon-sy">;  }?>
2
3
4
5 if (get_previous_post()) { echo  previous_post_link('%link'class="crayon-sy">,__( '下一篇'class="crayon-sy">, 'lee' class="crayon-sy">),$in_same_cat = false,$excluded_categories = '11'class="crayon-sy">);  } else { echo '已最后'class="crayon-sy">;  }?>

12. 热门标签ajax加载

点击换一换

wordpress二次开发技巧之functions.php篇

01 // 热门标签ajax部分
02 function tagLoad(){
03     if( isset($_GET['action'class="crayon-sy">])){
04         if($_GET['action'class="crayon-sy">] == 'tag'class="crayon-h">  ){
05             echo wp_tag_cloud('smallest=10&largest=14&number=32&order=RAND'class="crayon-sy">);
06             die;
07         }
08     }
09
10 }
11 add_action('init'class="crayon-sy">, 'tagLoad'class="crayon-sy">);

HTML部分

1 class="tag_change" href="crayon-sy">)."/?action=tag"; ?>">换一换

使用JS实现点击交互

01 // 标签云ajax
02     $(".tag_change").click(function(){
03         $.ajax({
04             url: $(this).attr("href"),
05             type: 'get'class="crayon-sy">,
06             beforeSend: function() {
07                 // 可以显示loading
08             },
09             error: function(error) {
10                 // 错误处理
11             },
12             success: function(data) {
13                 // 成功返回数据，先清空初始标签，装载新数据淡入
14                 $(".tag_content").empty().append($(data).fadeIn(200));
15             }
16         });
17         return false;
18     });

13. 外链加上nofollow

防止引入的网站有问题，被降权

01 // 文章外部链接加上nofollow
02 add_filter( 'the_content', 'cn_nf_url_parse');
03 function cn_nf_url_parse( $content ) {
04
05   $regexp = "]*href=("??)([^" >]*?)1[^>]*>";
06   if(preg_match_all("/$regexp/siU", $content, $matches, PREG_SET_ORDER)) {
07     if( !empty($matches) ) {
08
09       $srcUrl = get_option('siteurl');
10       for ($i=0; $i < count($matches); $i++)
11       {
12
13         $tag = $matches[$i][0];
14         $tag2 = $matches[$i][0];
15         $url = $matches[$i][0];
16
17         $noFollow = '';
18
19         $pattern = '/targets*=s*"s*_blanks*"/';
20         preg_match($pattern, $tag2, $match, PREG_OFFSET_CAPTURE);
21         if( count($match) < 1 )
22           $noFollow .= ' target="_blank" ';
23
24         $pattern = '/rels*=s*"s*[n|d]ofollows*"/';
25         preg_match($pattern, $tag2, $match, PREG_OFFSET_CAPTURE);
26         if( count($match) < 1 )
27           $noFollow .= ' rel="nofollow" ';
28
29         $pos = strpos($url,$srcUrl);
30         if ($pos === false) {
31           $tag = rtrim ($tag,'>');
32           $tag .= $noFollow.'>';
33           $content = str_replace($tag2,$tag,$content);
34         }
35       }
36     }
37   }
38
39   $content = str_replace(']]>', ']]>', $content);
40   return $content;
41
42 }

14. 图片懒加载lazyload3. 外链加上nofollow

1 function lazyload($content) {
2   if(!is_feed()||!is_robots) {
3     $content=preg_replace('/"]([^'"]+)['"](.*)>/i',"$1data-original="$2" src="data:image/gif;base64,R0lGODlhAQABAIAAAOHh4QAAACH5BAAAAAAALAAAAAABAAEAQAICRAEAOw=="$3>n",$content);
4   }
5   return $content;
6 }
7 add_filter ('the_content', 'lazyload');

JS代码（需引入jquery.lazyload.js）

1 // lazyload
2 $("img").lazyload({
3     effect : "fadeIn",
4     threshold : 100,
5 });

15. 获取文章中第一张图

如跑马灯图

wordpress二次开发技巧之functions.php篇

01 // 获取文章中第一张图
02 function wpdx_postimage($atts, $content = null) {
03   extract(shortcode_atts(array(
04     "size" => 'full',
05     "float" => 'none'
06   ), $atts));
07   $images =& get_children( 'post_type=attachment&post_mime_type=image&post_parent='. get_the_id() );
08   foreach( $images as $imageID => $imagePost )
09   $fullimage = wp_get_attachment_image($imageID, $size, false);
10   $imagedata = wp_get_attachment_image_src($imageID, $size, false);
11   $width = ($imagedata[1]+2);
12   $height = ($imagedata[2]+2);
13   return $fullimage;
14 }
15 add_shortcode("postimage", "wpdx_postimage");

显示图片

1 "" target="_blank">
2     echo do_shortcode("[postimage]"); ?>
3

16. 截取摘要

wordpress二次开发技巧之functions.php篇

01 // 摘要字数限制
02 function new_excerpt_length($length) {
03   return 100;
04 }
05 add_filter('excerpt_length', 'new_excerpt_length');
06
07 // 摘要...
08 function new_excerpt_more( $more ) {
09   return '...';
10 }
11 add_filter('excerpt_more', 'new_excerpt_more');

17. 获取文章第一个分类目录

因为一篇文章可能属于多个目录，有些地方只需要输出一个

1 // 获取文章第一个分类目录
2 function get_first_category(){
3   $category = get_the_category();
4   if($category[0]){
5     echo '.get_category_link($category[0]->term_id ).'">'.$category[0]->cat_name.'';
6   }
7 }
8 add_filter('get_first_category', 'get_first_category');

HTML

1

18. 分类页获得文章简介

wordpress二次开发技巧之functions.php篇

1 // 获得category简介
2 function get_category_expert($length=240){
3   $content = get_the_content();
4   $trimmed_content = wp_trim_words( $content, $length, '. get_permalink() .'"> [...]' );
5   echo $trimmed_content;
6 }
7 add_filter('get_category_expert', 'get_category_expert');

19. 根据页面类型指定每页显示的文章数

01 // 根据页面类型指定每页显示的文章数
02 function custom_posts_per_page($query){
03     if(is_home()){
04         $query->set('posts_per_page',9);//首页每页显示8篇文章
05     }
06     if(is_search()){
07         $query->set('posts_per_page',5);//搜索页显示所有匹配的文章，不分页
08     }
09     if(is_archive()){
10         $query->set('posts_per_page',-1);//archive每页显示25篇文章
11       }
12     if(is_tag()){
13         $query->set('posts_per_page',4);//archive每页显示25篇文章
14     }
15     if(is_category()){
16         $query->set('posts_per_page',9);//archive每页显示25篇文章
17     }
18     if(is_category(11)){
19         $query->set('posts_per_page',-1);//archive每页显示25篇文章
20     }
21 }//function
22 //this adds the function above to the 'pre_get_posts' action
23 add_action('pre_get_posts','custom_posts_per_page');

20. 缩略图

01 //添加特色缩略图支持
02 if ( function_exists('add_theme_support') )add_theme_support('post-thumbnails');
03
04 /*
05 * 缩略图
06 */
07
08 function dm_the_thumbnail() {
09
10     global $post;
11
12     // 判断该文章是否设置的缩略图，如果有则直接显示
13
14     if ( has_post_thumbnail() ) {
15
16         echo '.get_permalink().'" title="阅读全文">';
17
18         the_post_thumbnail('thumbnail');
19
20         echo '';
21
22     } else { //如果文章没有设置缩略图，则查找文章内是否包含图片
23
24         $content = $post->post_content;
25
26         preg_match_all('/"]?(.+?)['"]?(?:(?: |t|r|n)+.*?)?>/sim', $content, $strResult, PREG_PATTERN_ORDER);
27
28         $n = count($strResult[1]);
29
30         if($n > 0){ // 如果文章内包含有图片，就用第一张图片做为缩略图
31             // 为了得到第一张图片的215x115尺寸，得用正则替换格式
32             $thumb_first = $strResult[1][0];
33             $thumb_split = strrpos($thumb_first, '.');
34             $thumb_before = substr($thumb_first, 0, $thumb_split);
35             $thumb_after = substr($thumb_first, $thumb_split, strlen($thumb_first));
36             $reg = "/-d*xd*/im";
37             $thumb_before = preg_replace($reg, "", $thumb_before);
38             $thumb_src = $thumb_before.'-215x115'.$thumb_after;
39             echo '.get_permalink().'" title="阅读全文">.$thumb_src.'" alt="缩略图" />';
40
41         }else { // 如果文章内没有图片，则用默认的图片。
42             $random= mt_rand(0, 19);
43             echo '.get_permalink().'" title="阅读全文">.get_bloginfo('template_url').'/images/thumbnail/default_thumbnail_'.$random.'.jpg" alt="缩略图" />';
44
45         }
46
47     }
48
49 }

显示缩略图

1 // 第一种
2 if (has_post_thumbnail()){ the_post_thumbnail();} ?>
3
4
5 // 第二种
6

转载于:https://www.cnblogs.com/wpxuexi/p/6377510.html