网上找了一段WordPress发布文章时远程图片自动下载，测试后发现是可用的，但是都存在一个问题，下载后替换的图片的地址不正确，使得不能在文章中正常显示，于是陌小雨帮大家修复了下，有需要的可以尝试下：

add_filter('content_save_pre', 'auto_save_image');
function auto_save_image($content) {
 $upload_path = '';
 $upload_url_path = get_bloginfo('url');
   
 //上传目录
 if (($var = get_option('upload_path')) !=''){
 $upload_path = $var;
 } else {
 $upload_path = 'wp-content/uploads';
 }
 if(get_option('uploads_use_yearmonth_folders')) {
 $upload_path .= '/'.date("Y",time()).'/'.date("m",time());
 }
   
 //文件地址
 if(($var = get_option('upload_url_path')) != '') {
 $upload_url_path = $var;
 } else {
 $upload_url_path = bloginfo('url');
 }
 if(get_option('uploads_use_yearmonth_folders')) {
 $upload_url_path .= '/'.date("Y",time()).'/'.date("m",time());
 }
   
 require_once ("../wp-includes/class-snoopy.php");
 $snoopy_Auto_Save_Image = new Snoopy;
   
 $img = array();
   
 //以文章的标题作为图片的标题
 if ( !empty( $_REQUEST['post_title'] ) )
 $post_title = wp_specialchars( stripslashes( $_REQUEST['post_title'] ));
 $text = stripslashes($content);
 if (get_magic_quotes_gpc()) $text = stripslashes($text);
 preg_match_all("/ src=(\"|\'){0,}(http:\/\/(.+))(\"|\'|\s)/is",$text,$img);
 $img = array_unique(dhtmlspecialchars($img[2]));
 foreach ($img as $key => $value){
 set_time_limit(180); //每个图片最长允许下载时间,秒
 if(str_replace(get_bloginfo('url'),"",$value)==$value&&str_replace(get_bloginfo('home'),"",$value)==$value){
 //判断是否是本地图片，如果不是，则保存到服务器
 $fileext = substr(strrchr($value,'.'),1);
 $fileext = strtolower($fileext);
 if($fileext==""||strlen($fileext)>4)
 $fileext = "jpg";
 $savefiletype = array('jpg','gif','png','bmp');
 if (in_array($fileext, $savefiletype)){
 if($snoopy_Auto_Save_Image->fetch($value)){
 $get_file = $snoopy_Auto_Save_Image->results;
 }else{
 echo "error fetching file: ".$snoopy_Auto_Save_Image->error."<br>";
 echo "error url: ".$value;
 die();
 }
 $filetime = time();
 $filepath = "/".$upload_path;//图片保存的路径目录
 !is_dir("..".$filepath)mkdirs("..".$filepath) : null;
 //$filename = date("His",$filetime).random(3);
 $filename = substr($value,strrpos($value,'/'),strrpos($value,'.')-strrpos($value,'/'));
   
 //$e = '../'.$filepath.$filename.'.'.$fileext;
 //if(!is_file($e)) {
 // copy(htmlspecialchars_decode($value),$e);
 //}
 $fp = @fopen("..".$filepath.$filename.".".$fileext,"w");
 @fwrite($fp,$get_file);
 fclose($fp);
   
   
   
 $wp_filetype = wp_check_filetype( $filename.".".$fileext, false );
 $type = $wp_filetype['type'];
 $post_id = (int)$_POST['temp_ID2'];
 $title = $post_title;
$url ='http://127.0.0.1/wp-content/uploads'.$filename.".".$fileext;
 $file = $_SERVER['DOCUMENT_ROOT'].$filepath.$filename.".".$fileext;
   
 //添加数据库记录
 $attachment = array(
 'post_type' => 'attachment',
 'post_mime_type' => $type,
 'guid' => $url,
 'post_parent' => $post_id,
 'post_title' => $title,
 'post_content' => '',
 );
 $id = wp_insert_attachment($attachment, $file, $post_parent);
 $text = str_replace($value,$url,$text); //替换文章里面的图片地址
 }
 }
 }
 $content = AddSlashes($text);
 remove_filter('content_save_pre', 'auto_save_image');
 return $content;
}
   
function mkdirs($dir)
{
 if(!is_dir($dir))
 {
 mkdirs(dirname($dir));
 mkdir($dir);
 }
 return ;
}
function dhtmlspecialchars($string) {
 if(is_array($string)) {
 foreach($string as $key => $val) {
 $string[$key] = dhtmlspecialchars($val);
 }
 }else{
 $string = str_replace('&', '&', $string);
 $string = str_replace('"', '"', $string);
 $string = str_replace('<', '<', $string);
 $string = str_replace('>', '>', $string);
 $string = preg_replace('/&(#\d;)/', '&\1', $string);
 }
 return $string;
}

把上述代码中的127.0.0.1替换为你自己的网站域名即可。