js:

view :

</view>

后台接口处理：

 function doPageGetWxcode(){//接口地址
    $code = $_GPC['code'];
$res=getunionId($code,$_W);

}

   function getopenida($code){   //授权获取code 取用户openid
    $appid = '*****************';//公众号wx5d6dd710f5e8c4a3
    $appsecret = '*****************';//公众号 appsecret 
    $url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=".$appid."&secret=".$appsecret."&code=".$code."&grant_type=authorization_code";//基础接口
          $curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
//执行
$data = curl_exec($curl);
curl_close($curl);
           $data = json_decode($data,true);
      return $data['openid'];
    }

  function getunionId($code,$_W){
        $access_token=getaccess_tokenc($_W);//获取access_token；
        $openid=getopenida($code);//获取openid
        $url = "https://api.weixin.qq.com/cgi-bin/user/info?access_token=".$access_token."&openid=".$openid."&lang=zh_CN";
        $curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
$datao = curl_exec($curl);
curl_close($curl);
           $datao = json_decode($datao,true);

/**通过access_token和openid 获取unionid**/
        $unionid=$datao['unionid'];
        $res="**************"//查询是否存在unionid的数据
        if($res){    
       存在 修改操作数据
        }else{
      不存在 新增数据
        }

}

  function getaccess_tokenc($_W){       
      global $_GPC, $_W;
        $tokenName='access_token'.$_W['uniacid'];
        $timeName='access_token_time'.$_W['uniacid'];
        load()->classs('wesession');
        WeSession::start($_W['uniacid'], CLIENT_IP);
      if($_SESSION[$timeName]<time() || !$_SESSION[$tokenName]){  
    $appid = '*****************';//公众号wx5d6dd710f5e8c4a3
    $appsecret = '*****************';//公众号 appsecret 
     // $url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=".$appid."&secret=".$appsecret."&code=".$code."&grant_type=authorization_code";
      $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=".$appid."&secret=".$appsecret."";
     $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL,$url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER,0);
            $data = curl_exec($ch);
            curl_close($ch);
            $data = json_decode($data,true);

//access_token需缓存
            $_SESSION[$tokenName]=$data['access_token'];
            $_SESSION[$timeName]=time()+300;
            return $data['access_token'];
      }else{      
       return $_SESSION[$tokenName];
      }
    }

基于微擎开发