首先，在主题functions.php中增加下面的代码：

function wp_dashboard_GongGao() {

if($_POST && $_POST['update-GongGao'] == 1){

check_admin_referer('GongGao');

$GongGao = serialize($_POST['GongGao']);

update_option('GongGao',$GongGao) or add_option('GongGao',$GongGao);

}

?>

<form method="post" action="<?php echo add_query_arg ('time',time()); ?>">

<?php if($_POST && $_POST['update-GongGao'] == 1)echo '<p><span>更新公告成功</span></p>'; ?>

<?php $GongGao = unserialize(get_option('GongGao')); ?>

公告链接（留空则无链接）：<input type="text" name="GongGao[link]" value="<?php if(isset($GongGao['link']))echo stripslashes($GongGao['link']); ?>" />

<p>公告信息

<textarea name="GongGao[content]" rows="4"><?php echo stripslashes($GongGao['content']); ?></textarea></p>

<input type="submit" value="提交" />

<?php wp_nonce_field('GongGao'); ?>

<input type="hidden" name="update-GongGao" value="1" />

</form>

<?php

}

function my_wp_dashboard_setup() {

if(current_user_can('edit_themes'))wp_add_dashboard_widget('wp_dashboard_GongGao','网站公告','wp_dashboard_GongGao');

}

add_action('wp_dashboard_setup','my_wp_dashboard_setup');

添加这段代码之后，进入后台首页就能找到一个关键，让我们填写公告内容。

之后在前台如何调用呢？在需要之处使用下面的代码即可：

<?php $GongGao = unserialize(get_option('GongGao'));if(!empty($GongGao['content'])): ?>

<div id="site-gonggao"><?php echo ($GongGao['link'] ? '<a href="'.$GongGao['link'].'">' : '').$GongGao['content'].($GongGao['link'] ? '</a>' : ''); ?></div>

<?php endif; ?>

至于样式之类，可根据自身需求进行调整。