<?php
$home = ‘http://’.$_SERVER[‘HTTP_HOST’];
$siteurl = ‘http://’.$_SERVER[‘HTTP_HOST’];
define(‘WP_HOME’, $home);
define(‘WP_SITEURL’, $siteurl);
?>

这样修改后，在后台的 setting-options 页面，只能显示而不能修改home和siteurl两个值（因为它们已经被定义成两个常量了，呵呵），它们完全是根据访问域名显示的。

2、修改多媒体插件
更改多媒体插件插入图片时使用相对路径！
另外两种方式如下：
1.修改wordpress根目录下的wp-config.php，在该文件中加入一下两行

define(‘WP_HOME’, ”);
define(‘WP_SITEURL’, ”);

保存，OK了！但是这种修改方式是只能用户网网站根目录，并且使用默认的80端口。
如果你不是用网站的根目录，或者用非80端口，那就用第二种方法：
2.打开wp-includes/post.php文件，修改函数wp_get_attachment_url为如下代码：

/**
* Retrieve the URL for an attachment.
*
* @since 2.1.0
*
* @param int $post_id Attachment ID.
* @return string
*/
function wp_get_attachment_url( $post_id = 0 ) {
$file_dir=dirname(__FILE__);
$server_root=$_SERVER[DOCUMENT_ROOT];
$file_dir=substr($file_dir,strlen($server_root));
$file_dir=substr($file_dir,0,-12);
if($file_dir!=”){
$file_dir=’/’.substr($file_dir,1);
}
$post_id = (int) $post_id;
if ( !$post = get_post( $post_id ) )
return false;

if ( ‘attachment’ != $post->post_type )
return false;

$url = ”;
if ( $file = get_post_meta( $post->ID, ‘_wp_attached_file’, true) ) { //Get attached file
if ( ($uploads = wp_upload_dir()) && false === $uploads[‘error’] ) { //Get upload directory
if ( 0 === strpos($file, $uploads[‘basedir’]) ) //Check that the upload base exists in the file location
//$url = str_replace($uploads[‘basedir’], $uploads[‘baseurl’], $file); //replace file location with url location
$url=$file_dir.’/wp-content/uploads/’.$file;
elseif ( false !== strpos($file, ‘wp-content/uploads’) )
//$url = $uploads[‘baseurl’] . substr( $file, strpos($file, ‘wp-content/uploads’) + 18 );
$url=$file_dir.’/wp-content/uploads/’.$file;
else
//$url = $uploads[‘baseurl’] . “/$file”; //Its a newly uploaded file, therefor $file is relative to the basedir.
$url=$file_dir.’/wp-content/uploads/’.$file;
}
}

if ( empty($url) ) //If any of the above options failed, Fallback on the GUID as used pre-2.7, not recommended to rely upon this.
$url = get_the_guid( $post->ID );

/**
* Filter the attachment URL.
*
* @since 2.1.0
*
* @param string $url URL for the given attachment.
* @param int $post_id Attachment ID.
*/
$url = apply_filters( ‘wp_get_attachment_url’, $url, $post->ID );

if ( empty( $url ) )
return false;

return $url;
}

原文地址：http://blog.zhu-hai.com/web/38.html