php获取微信openid

使用微信接口，无论是自动登录还是微信支付我们首先需要获取的就是openid,获取openid的方式有两种，一种是在关注的时候进行获取，这种订阅号就可以获取的到，第二种是通过网页授权获取，这种获取需要的是认证服务号。

今天我要说的是第二种网页授权获取openid。

 <?php
 /**
  * 微信授权相关接口
  *
  * @link http://www.phpddt.com
  */
 class Wchat
 {
     private $app_id = 'wxaf04d17c0694fd82';
     private $app_secret = 'a3df3e828bf6307b2ed9daeb407ee624';
     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 ($debug) {
             echo "=====post data======\r\n";
             var_dump($postfields);
             echo '=====info=====' . "\r\n";
             print_r(curl_getinfo($ci));
             echo '=====$response=====' . "\r\n";
             print_r($response);
         }
         curl_close($ci);
         return array($http_code, $response);
     }
 }

 //getOpenid($turl)这个方法就是获取openid的方法。
 //前端调用代码如下:
 $openid=isset($_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()+86400*30);
     }
 }
 echo $openid;
 ?>