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'] = '';
 }
 $content=''.chr(13).'';
 $content.='
 http://www.xxx.com
 '.$today.'
 always
 0.9
 
 '.chr(13);
 foreach($data_array as $data){
  $content.=create_item($data);
 }
 $content.='';
 $fp=fopen('sitemap.xml','w+');
 fwrite($fp,$content);
 fclose($fp);
}
function create_item($data){
    $item=" ";
    $item.="".$data['loc']." ";
    $item.="".$data['lastmod']." ";
    $item.="".$data['changefreq']." ";
    $item.="