How to obtain the user's OpenID on the WeChat public platform webpage

After you click the view type button in the custom menu of WeChat, the WeChat client will open the url value (webpage link) filled in by the developer in the button to open the webpage, however, view cannot obtain the user's openid. You must use the WeChat "webpage authorization to obtain the user's basic information" advanced interface to obtain the user's personal login information.

Method

1. Configure the webpage authorization callback domain name, such as www.111cn.net

2. Simulate the third-party web page of public account, http://www.111cn.net/getcodeurl.php

<? Php
      
If (isset ($ _ SESSION ['user']) {
Print_r ($ _ SESSION ['user']);
Exit;
    }
$ APPID = 'appid of public account on WeChat ';
$ REDIRECT_URI = 'http: // www.111cn.net/callback.php ';
$ Scope = 'snsapi _ base ';
// $ Scope = 'snsapi _ userinfo'; // authorization required
$ Url = 'https: // open.weixin.qq.com/connect/oauth2/authorize? Appid = '. $ APPID. '& redirect_uri = '. urlencode ($ REDIRECT_URI ). '& response_type = code & scope = '. $ scope. '& state = '. $ state. '# wechat_redirect ';
    
Header ("Location:". $ url );
?>

3. In the redirection url of a third-party webpage, first obtain the code from the request, and then exchange openid and access_token based on the code, then, you can call the relevant interfaces of WeChat to query User information based on openid and access_token.

<? Php
// Http://www.111cn.net/callback.php
      
$ Appid = "appid of WeChat official account ";
$ Secret = "app secret of WeChat official account ";
$ Code = $ _ GET ["code"];
$ Get_token_url = 'https: // api.weixin.qq.com/sns/oauth2/access_token? Appid = '. $ appid.' & secret = '. $ secret.' & code = '. $ code.' & grant_type = authorization_code ';

$ Ch = curl_init ();
Curl_setopt ($ ch, CURLOPT_URL, $ get_token_url );
Curl_setopt ($ ch, CURLOPT_HEADER, 0 );
Curl_setopt ($ ch, CURLOPT_RETURNTRANSFER, 1 );
Curl_setopt ($ ch, CURLOPT_CONNECTTIMEOUT, 10 );
$ Res = curl_exec ($ ch );
Curl_close ($ ch );
$ Json_obj = json_decode ($ res, true );
      
// Query User information based on openid and access_token
$ Access_token = $ json_obj ['Access _ token'];
$ Openid = $ json_obj ['openid'];
$ Get_user_info_url = 'https: // api.weixin.qq.com/sns/userinfo? Access_token = '. $ access_token.' & openid = '. $ openid.' & lang = zh_CN ';
      
$ Ch = curl_init ();
Curl_setopt ($ ch, CURLOPT_URL, $ get_user_info_url );
Curl_setopt ($ ch, CURLOPT_HEADER, 0 );
Curl_setopt ($ ch, CURLOPT_RETURNTRANSFER, 1 );
Curl_setopt ($ ch, CURLOPT_CONNECTTIMEOUT, 10 );
$ Res = curl_exec ($ ch );
Curl_close ($ ch );
      
// Parse json
$ User_obj = json_decode ($ res, true );
$ _ SESSION ['user'] = $ user_obj;
Print_r ($ user_obj );
      
?>

References

Webpage authorization to obtain basic user information

Http://mp.weixin.qq.com/wiki/17/c0f37d5704f0b64713d5d2c37b468d75.html