php获取微信openid

<?php
/**
 * 微信授权相关接口
 * 
 * @link http://www.phpddt.com
 */
class Wchat
{
 private $app_id = 'wx444444444444';
 private $app_secret = '77777777';
 private $state='aaaa';
 /**
 * 获取微信授权链接
 * 
 * @param string $redirect_uri 跳转地址
 * @param mixed $state 参数
 */
 public function get_authorize_url($redirect_uri = '', $state = '')
 {
 $redirect_uri = urlencode($redirect_uri);
 return "https://open.weixin.qq.com/connect/oauth2/authorize?appid={$this->app_id}&redirect_uri={$redirect_uri}&response_type=code&scope=snsapi_userinfo&state={$state}#wechat_redirect";
 }
 /**
 * 获取微信openid
 */
 public function getOpenid($turl)
 {
 if (!isset($_GET['code'])){
 //触发微信返回code码
 
 $url=$this->get_authorize_url($turl, $this->state);
 
 Header("Location: $url");
 exit();
 } else {
 //获取code码，以获取openid
 $code = $_GET['code'];
 $access_info = $this->get_access_token($code);
 return $access_info;
 }
 
 }
 /**
 * 获取授权token网页授权
 * 
 * @param string $code 通过get_authorize_url获取到的code
 */
 public function get_access_token($code = '')
 {
 $appid=$this->app_id;
 $appsecret=$this->app_secret;
 
 $token_url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=".$appid."&secret=".$appsecret."&code=".$code."&grant_type=authorization_code";
 //echo $token_url;
 $token_data = $this->http($token_url);
 // var_dump( $token_data);
 if($token_data[0] == 200)
 {
 $ar=json_decode($token_data[1], TRUE);
 return $ar;
 }
 
 return $token_data[1];
 }
 
 
 public function http($url, $method='', $postfields = null, $headers = array(), $debug = false)
 {
 $ci = curl_init();
 /* Curl settings */
 curl_setopt($ci, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
 curl_setopt($ci, CURLOPT_CONNECTTIMEOUT, 30);
 curl_setopt($ci, CURLOPT_TIMEOUT, 30);
 curl_setopt($ci, CURLOPT_RETURNTRANSFER, true);
 
 switch ($method) {
 case 'POST':
 curl_setopt($ci, CURLOPT_POST, true);
 if (!empty($postfields)) {
 curl_setopt($ci, CURLOPT_POSTFIELDS, $postfields);
 $this->postdata = $postfields;
 }
 break;
 }
 curl_setopt($ci, CURLOPT_URL, $url);
 curl_setopt($ci, CURLOPT_HTTPHEADER, $headers);
 curl_setopt($ci, CURLINFO_HEADER_OUT, true);
 
 $response = curl_exec($ci);
 $http_code = curl_getinfo($ci, CURLINFO_HTTP_CODE);
 
 if ($debug) {
 echo "=====post data======
";
 var_dump($postfields);
 
 echo '=====info=====' . "
";
 print_r(curl_getinfo($ci));
 
 echo '=====$response=====' . "
";
 print_r($response);
 }
 curl_close($ci);
 return array($http_code, $response);
 }
 
}
?>

 $openid=isset($_COOKIE['openid'])?$_COOKIE['openid']:'';
 
 if(empty($openid))
 {
 $wchat=new wchat();
 $t_url='http://'.$_SERVER['HTTP_HOST'].'/user.php?act=register';
 
 $info=$wchat->getOpenid($t_url);
 
 if($info){
 $openid=$info['openid'];
 setcookie('openid',$openid,time()+800*30); 
 
 }
 
 }