微信第三方登录

<a href="https://open.weixin.qq.com/connect/oauth2/authorize?appid=appid&redirect_uri=http://www.xxxxxx.com/action/function/oauth2&response_type=code&scope=snsapi_userinfo&state=1#wechat_redirect">授权</a>

public function oauth2(){        　　 
    include('class_weixin_adv.php');            
    $weixin=new class_weixin_adv("appid", "secret");            
    if (isset($_GET['code'])){                
        $url="https://api.weixin.qq.com/sns/oauth2/access_token?appid=appid&secret=secret&code=".$_GET['code']."&grant_type=authorization_code";                
        $res = $weixin->https_request($url);                
        $res=(json_decode($res, true));                
        $row=$weixin->get_user_info($res['openid']);//获取用户信息入库                                
        if ($row['openid']) {                   
            //这里写上逻辑,存入cookie,数据库等操作                    
            cookie('weixin',$row['openid'],25920000);                                   
        }else{                   
            $this->error('授权出错,请重新授权!');                
        }            
    }else{                
        echo "NO CODE";            
    }            
        $this->display();        
}

<?php
/**
 * 微信SDK 
 */
class class_weixin_adv
{
    protected $appid = "";
    protected $appsecret = "";
 
    //构造函数，获取Access Token
    public function __construct($appid = NULL, $appsecret = NULL)
    {
        if($appid){
            $this->appid = $appid;
        }
        if($appsecret){
            $this->appsecret = $appsecret;
        }
 
        
        $this->lasttime = 1395049256;
        $this->access_token = "nRZvVpDU7LxcSi7GnG2LrUcmKbAECzRf0NyDBwKlng4nMPf88d34pkzdNcvhqm4clidLGAS18cN1RTSK60p49zIZY4aO13sF-eqsCs0xjlbad-lKVskk8T7gALQ5dIrgXbQQ_TAesSasjJ210vIqTQ";
 
        if (time() > ($this->lasttime + 7200)){
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=".$this->appid."&secret=".$this->appsecret;
            $res = $this->https_request($url);
            $result = json_decode($res, true);
            
            $this->access_token = $result["access_token"];
            $this->lasttime = time();
        }
    }//获取用户基本信息
    public function get_user_info($openid)
    {
        $url = "https://api.weixin.qq.com/cgi-bin/user/info?access_token=".$this->access_token."&openid=".$openid."&lang=zh_CN";
        $res = $this->https_request($url);
        return json_decode($res, true);
    }
 
//https请求
    public function https_request($url, $data = null)
    {
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_URL, $url);
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);
        if (!empty($data)){
            curl_setopt($curl, CURLOPT_POST, 1);
            curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
        }
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
        $output = curl_exec($curl);
        curl_close($curl);
        return $output;
    }
}