function sitemapxml(){
 $user = M('sethouse');//thinkphp 数据链接
 $today = date("Y-m-d",time());
 $yesterday  = mktime(0, 0, 0, date("m")  , date("d")-1, date("Y"));
 $lastweek = strtotime("-1 week");
 $link = M();
 $yesterdayArr = $link->query("select * from pre_sethouse where status=1 and time>$yesterday");//昨天
 $lastweekArr = $link->query("select * from pre_sethouse where  status=1 and time>$lastweek");//上周
 $url = "http://www.xxx.com/House/housecontent/id/";
 foreach($yesterdayArr as $k=>$v){
  $data_array[$k]['loc'] = $url.$v['hid'];
  $data_array[$k]['lastmod'] = $today;
  $data_array[$k]['changefreq'] = 'always';
  $data_array[$k]['priority'] = '0.6';
  $data_array[$k]['data'] = '<display></display>';
 }
 $content='<?xml version="1.0" encoding="UTF-8"?><urlset>'.chr(13).'';
 $content.='<url>
 <loc>http://www.xxx.com</loc>
 <lastmod>'.$today.'</lastmod>
 <changefreq>always</changefreq>
 <priority>0.9</priority>
 <data><display></display></data>
 </url>'.chr(13);
 foreach($data_array as $data){
  $content.=create_item($data);
 }
 $content.='</urlset>';
 $fp=fopen('sitemap.xml','w+');
 fwrite($fp,$content);
 fclose($fp);
}
function create_item($data){
    $item="<url>\n";
    $item.="<loc>".$data['loc']."</loc>\n";
    $item.="<lastmod>".$data['lastmod']."</lastmod>\n";
    $item.="<changefreq>".$data['changefreq']."</changefreq>\n";
    $item.="<priority>".$data['priority']."</priority>\n";
 $item.="<data>".$data['data']."</data>\n";
    $item.="</url>\n";
    return $item;
}