在upload文件夹下新建一个目录

function my_upload_dir()
{
    $upload = wp_upload_dir();
    $upload_dir = $upload['basedir'];
    $upload_dir = $upload_dir . '/mypluginfiles';
    if (!is_dir($upload_dir)) {
        mkdir($upload_dir, 448);
    }
}
register_activation_hook(__FILE__, 'my_upload_dir');

去除文章图片自动添加尺寸的问题

add_filter( 'post_thumbnail_html', 'remove_width_attribute', 10 );
add_filter( 'image_send_to_editor', 'remove_width_attribute', 10 );
 
function remove_width_attribute( $html ) {
   $html = preg_replace( '/(width|height)="d*"s/', "", $html );
   return $html;
}

WordPress后台自定义样式

add_action('admin_head', 'my_custom_fonts');
 
function my_custom_fonts() {
  echo '';
}

使用短代码使用bloginfo函数

function digwp_bloginfo_shortcode( $atts ) {
   extract(shortcode_atts(array(
       'key' => '',
   ), $atts));
   return get_bloginfo($key);
}
add_shortcode('bloginfo', 'digwp_bloginfo_shortcode');

使用的时候，这样就好了[bloginfo key='name']

使用短代码防止WordPress自动格式化

function my_formatter($content) {
       $new_content = '';
       $pattern_full = '{([raw].*?[/raw])}is';
       $pattern_contents = '{[raw](.*?)[/raw]}is';
       $pieces = preg_split($pattern_full, $content, -1, PREG_SPLIT_DELIM_CAPTURE);
 
       foreach ($pieces as $piece) {
               if (preg_match($pattern_contents, $piece, $matches)) {
                       $new_content .= $matches[1];
               } else {
                       $new_content .= wptexturize(wpautop($piece));
               }
       }
 
       return $new_content;
}
 
remove_filter('the_content', 'wpautop');
remove_filter('the_content', 'wptexturize');
 
add_filter('the_content', 'my_formatter', 99);

使用方法：[raw]Unformatted code[/raw]

通过ID获取文章内容

function get_the_content_by_id($post_id) {
  $page_data = get_page($post_id);
  if ($page_data) {
    return $page_data->post_content;
  }
  else return false;
}

在控制面板创建一个小工具

// Function that outputs the contents of the dashboard widget
function dashboard_widget_function( $post, $callback_args ) {
    echo "Hello World, this is my first Dashboard Widget!";
}
 
// Function used in the action hook
function add_dashboard_widgets() {
    wp_add_dashboard_widget('dashboard_widget', 'Example Dashboard Widget', 'dashboard_widget_function');
}
 
// Register the new dashboard widget with the 'wp_dashboard_setup' action
add_action('wp_dashboard_setup', 'add_dashboard_widgets' );

控制面板创建一个表格小工具

// Function that outputs the contents of the dashboard widget
function dashboard_widget_function( $post, $callback_args ) {
   
//Put your all code here which generate the output of summary box
 
$site_users =  get_users();
foreach ( $site_users as $user ) {
 
     echo $user->display_name;
     echo $user->roles[0];
     echo get_edit_user_link( $user->ID );
 
  }
 
}

更换控制面板logo

//hook the administrative header output
add_action('admin_head', 'my_custom_logo');
 
function my_custom_logo() {
echo '
  
  ';
}

禁用可视化编辑器自动补全标签

//disable wpautop filter
remove_filter ('the_content',  'wpautop');

增加减少WordPress用户角色

function wps_add_role() {
    add_role( 'manager', 'Manager', 
             array(
                  'read',
                  'edit_posts',
                  'delete_posts',
                  )
    );
}
add_action( 'init', 'wps_add_role' );
 
function wps_remove_role() {
    remove_role( 'editor' );
    remove_role( 'author' );
    remove_role( 'contributor' );
    remove_role( 'subscriber' );
}
add_action( 'init', 'wps_remove_role' );

添加图片附件上传时候的默认项

function wps_attachment_display_settings() {
	update_option( 'image_default_align', 'center' );
	update_option( 'image_default_link_type', 'none' );
	update_option( 'image_default_size', 'large' );
}
add_action( 'after_setup_theme', 'wps_attachment_display_settings' );

图片上传时候添加自定义尺寸

if ( function_exists( 'add_image_size' ) ) {
    add_image_size( 'new-size', 300, 100, true ); //(cropped)
}
 
add_filter('image_size_names_choose', 'my_image_sizes');
function my_image_sizes($sizes) {
        $addsizes = array(
                "new-size" => __( "自定义尺寸")
                );
        $newsizes = array_merge($sizes, $addsizes);
        return $newsizes;
}

更换WordPress默认的用户角色名

function wps_change_role_name() {
    global $wp_roles;
    if ( ! isset( $wp_roles ) )
        $wp_roles = new WP_Roles();
    $wp_roles->roles['contributor']['name'] = 'Owner';
    $wp_roles->role_names['contributor'] = 'Owner';           
}
add_action('init', 'wps_change_role_name');

主题激活后自动创建页面

if (isset($_GET['activated']) && is_admin()){
 
	$new_page_title = 'This is the page title';
	$new_page_content = 'This is the page content';
	$new_page_template = ''; //ex. template-custom.php. Leave blank if you don't want a custom page template.
 
	//don't change the code bellow, unless you know what you're doing
 
	$page_check = get_page_by_title($new_page_title);
	$new_page = array(
		'post_type' => 'page',
		'post_title' => $new_page_title,
		'post_content' => $new_page_content,
		'post_status' => 'publish',
		'post_author' => 1,
	);
	if(!isset($page_check->ID)){
		$new_page_id = wp_insert_post($new_page);
		if(!empty($new_page_template)){
			update_post_meta($new_page_id, '_wp_page_template', $new_page_template);
		}
	}
 
}

非管理员不得访问后台

   add_action( 'init', 'blockusers_wps_init' );
    function blockusers_wps_init() {
            if ( is_admin() && ! current_user_can( 'administrator' ) ) {
                    wp_redirect( home_url() );//滚回首页吧
                    exit;
            }
    }

用户注册成功后跳转

function wps_registration_redirect(){
    return home_url( '/finished/' );
}
add_filter( 'registration_redirect', 'wps_registration_redirect' );

给自定义文章添加概览计数

add_filter( 'dashboard_glance_items', 'custom_glance_items', 10, 1 );
 
function custom_glance_items( $items = array() ) {
 
    $post_types = array( 'post_type_1', 'post_type_2' );
    
    foreach( $post_types as $type ) {
 
        if( ! post_type_exists( $type ) ) continue;
 
        $num_posts = wp_count_posts( $type );
        
        if( $num_posts ) {
      
            $published = intval( $num_posts->publish );
            $post_type = get_post_type_object( $type );
            
            $text = _n( '%s ' . $post_type->labels->singular_name, '%s ' . $post_type->labels->name, $published, 'your_textdomain' );
            $text = sprintf( $text, number_format_i18n( $published ) );
            
            if ( current_user_can( $post_type->cap->edit_posts ) ) {
                $items[] = sprintf( '%2$s', $type, $text ) . "n";
            } else {
                $items[] = sprintf( '%2$s', $type, $text ) . "n";
            }
        }
    }
    
    return $items;
}

来点样式

#dashboard_right_now a.post_type-count:before,
#dashboard_right_now span.post_type-count:before {
  content: "f109";
}

给可视化编辑器添加短代码

add_action('media_buttons','add_sc_select',11);
function add_sc_select(){
    echo ' 
                        短代码
                        [html]
                        [css[
                        [javascript]
        ';
}
add_action('admin_head', 'button_js');
function button_js() {
	echo '';
}

给文章添加特色图才给发布，否则不给发

add_action('save_post', 'wpds_check_thumbnail');
add_action('admin_notices', 'wpds_thumbnail_error');
 
function wpds_check_thumbnail($post_id) {
 
    // change to any custom post type 
    if(get_post_type($post_id) != 'post')
        return;
    
    if ( !has_post_thumbnail( $post_id ) ) {
        // set a transient to show the users an admin message
        set_transient( "has_post_thumbnail", "no" );
        // unhook this function so it doesn't loop infinitely
        remove_action('save_post', 'wpds_check_thumbnail');
        // update the post set it to draft
        wp_update_post(array('ID' => $post_id, 'post_status' => 'draft'));
 
        add_action('save_post', 'wpds_check_thumbnail');
    } else {
        delete_transient( "has_post_thumbnail" );
    }
}
 
function wpds_thumbnail_error()
{
    // check if the transient is set, and display the error message
    if ( get_transient( "has_post_thumbnail" ) == "no" ) {
        echo "
您必须选择一个特色图片，您的文章现已被保存，但是无法发布。
";
        delete_transient( "has_post_thumbnail" );
    }
 
}

要求评论字数的最小值

add_filter( 'preprocess_comment', 'minimal_comment_length' );
 
function minimal_comment_length( $commentdata ) {
    $minimalCommentLength = 20;//这里自己改
 
    if ( strlen( trim( $commentdata['comment_content'] ) ) < $minimalCommentLength ){
    wp_die( '评论最起码要有 ' . $minimalCommentLength . ' 个字符哦.' );
    }
 
    return $commentdata;
}	

用颜色区分后台文章的状态

add_action('admin_footer','posts_status_color');
function posts_status_color(){
?>


看下图


给特定文章/页面强制SSL浏览
function wps_force_ssl( $force_ssl, $post_id = 0, $url = '' ) {
    if ( $post_id == 25 ) {
        return true
    }
    return $force_ssl;
}
 
add_filter('force_ssl' , 'wps_force_ssl', 10, 3);

给后台添加指引
add_action( 'admin_enqueue_scripts', 'my_admin_enqueue_scripts' );
function my_admin_enqueue_scripts() {
    wp_enqueue_style( 'wp-pointer' );
    wp_enqueue_script( 'wp-pointer' );
    add_action( 'admin_print_footer_scripts', 'my_admin_print_footer_scripts' );
}
function my_admin_print_footer_scripts() {
    $pointer_content = '
云落的通知
';
    $pointer_content .= '
这是一个通知
';
?>
   

给WordPress添加欢迎信息

    

        
欢迎来自百度的亲们！
    


注意：本段代码是添加在主题header.php文件里面的，自己辅助下样式吧
角色变换时候发送电子邮件
function user_role_update( $user_id, $new_role ) {
        $site_url = get_bloginfo('wpurl');
        $user_info = get_userdata( $user_id );
        $to = $user_info->user_email; 
        $subject = "Role changed: ".$site_url."";
        $message = "Hello " .$user_info->display_name . " 亲，您在".$site_url.", 角色已经变为 " . $new_role;
        wp_mail($to, $subject, $message);
}
add_action( 'set_user_role', 'user_role_update', 10, 2);

短代码添加一个网站的截图
function wps_screenshot($atts, $content = null) {
        extract(shortcode_atts(array(
			"screenshot" => 'http://s.wordpress.com/mshots/v1/',
			"url" => 'http://',
			"alt" => 'screenshot',
			"width" => '400',
			"height" => '300'
        ), $atts));
		return $screen = '';
}
add_shortcode("screenshot", "wps_screenshot");

使用：[screenshot url=”http://googlo.me” alt=”wordpress code snippets for your blog” width=”200″ height=”200″]
使用短代码添加倒计时功能
function content_countdown($atts, $content = null){
  extract(shortcode_atts(array(
     'month' => '',
     'day'   => '',
     'year'  => ''
    ), $atts));
    $remain = ceil((mktime( 0,0,0,(int)$month,(int)$day,(int)$year) - time())/86400);
    if( $remain > 1 ){
        return $daysremain = "
Just ($remain) days until content is available
";
    }else if($remain == 1 ){
	return $daysremain = "
Just ($remain) day until content is available
";
    }else{
        return $content;
    }
}
add_shortcode('cdt', 'content_countdown');

使用：[cdt month=”10″ day=”17″ year=”2011″]本次活动已过期，请下次再来！！！[/cdt]
强制控制面板显示一列
function single_screen_columns( $columns ) {
    $columns['dashboard'] = 1;
    return $columns;
}
add_filter( 'screen_layout_columns', 'single_screen_columns' );
 
function single_screen_dashboard(){return 1;}
add_filter( 'get_user_option_screen_layout_dashboard', 'single_screen_dashboard' );

让登陆用户自己选择登陆后的跳转
// Fields for redirect
function custom_login_fields() {
?>
	

		
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