微信公众号授权登录

微信公众号登录分两步走

1，获取code（让马化腾服务器请求我们的服务器并带上 code）

<div class="login-bg">
    <div class="login-btn clear">
        <a href="https://open.weixin.qq.com/connect/oauth2/authorize?appid=#########&redirect_uri=http://xxx.xxx.com/oauth2&response_type=code&scope=snsapi_base&state=123#wechat_redirect"><img src="/images/weixin.png" alt="微信公众号授权登录" alt="第三方" title="第三方">微信登录</a>
    </div>

</div>

2.获取用户的openid（通过传递过来的code，生成openid openid是唯一的）

function index(){
        //P($_GET);
        $state_value = '123';
        $appid = "xxxxxx";  // 正常时从数据库取数据
        $appsecret = "xxxxxxxxx"; // 正常时从数据库取数据
        $return_url = 'http://z-zfd.wh2013.com/index.php/oauth2';
        $get_codeUrl = 'https://open.weixin.qq.com/connect/oauth2/authorize?appid=xxxxxxx&redirect_uri='.$return_url.'&response_type=code&scope=snsapi_base&state='.$state_value.'#wechat_redirect';
        $get_accessUrl = 'https://api.weixin.qq.com/sns/oauth2/access_token?appid='.$appid.'&secret='.$appsecret.'&code='.$_GET['code']."&grant_type=authorization_code";


        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $get_accessUrl);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        $output = curl_exec($ch);
        curl_close($ch);
        $jsoninfo = json_decode($output, true);
      //  ajaxReturn($jsoninfo,'JSONP');
        $_SESSION['openid'] = $jsoninfo['openid'];

            $this->redirect('user_insert/index');

    }

3.根据openid获取用户信息（可以加上附加参数来做微信的分销功能）

//  获取微信 access_token  和 用户信息
function wx_get($openid,$chief){
    //整理 访问微信服务器的地址 start
    // P($_SESSION['wx_access_token']);
    $chief = $chief ? $chief : 'qrscene_666';
    $openid = $openid ? $openid : 'oNlhuxOMiPzAsCM8POazeEFzLLvk';
    $wx_access_token = $_SESSION['wx_access_token'] ? $_SESSION['wx_access_token'] :'';
    $wx_openid = $_SESSION['wx_openid'] ? $_SESSION['wx_openid'] :'';
    //  先判断 access_token 是否存在 不存在则 重新获取  如果存在则 判断 是否可以用 不可以用则重新生成
    if(!$wx_access_token || $wx_access_token ==''){
        $appid = "xxxx";  // 正常时从数据库取数据
        $appsecret = "xxxxxx"; // 正常时从数据库取数据
        $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$appid&secret=$appsecret";

        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        $output = curl_exec($ch);
        curl_close($ch);
        $jsoninfo = json_decode($output, true);
        $wx_access_token = $jsoninfo["access_token"];
        $_SESSION['wx_access_token'] = $wx_access_token;
    }else{
        $get_userinfo = "https://api.weixin.qq.com/cgi-bin/user/get?access_token=".$wx_access_token."&openid=".$wx_openid;
        $userinfo_ch = curl_init();
        curl_setopt($userinfo_ch, CURLOPT_URL, $get_userinfo);
        curl_setopt($userinfo_ch, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($userinfo_ch, CURLOPT_SSL_VERIFYHOST, FALSE);
        curl_setopt($userinfo_ch, CURLOPT_RETURNTRANSFER, 1);
        $userinfo_out = curl_exec($userinfo_ch);
        curl_close($userinfo_ch);

        $json_userinfo = json_decode($userinfo_out,true);
        if(isset($json_userinfo['errcode'])){
            $appid = "xxxx";  // 正常时从数据库取数据
            $appsecret = "xxxxxxx"; // 正常时从数据库取数据
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$appid&secret=$appsecret";

            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
            curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            $output = curl_exec($ch);
            curl_close($ch);
            $jsoninfo = json_decode($output, true);
            $wx_access_token = $jsoninfo["access_token"];
            $_SESSION['wx_access_token'] = $wx_access_token;
        }
    }
    $get_userinfo = "https://api.weixin.qq.com/cgi-bin/user/info?access_token=".$wx_access_token."&openid=".$openid;
    $user_ch = curl_init();
    curl_setopt($user_ch, CURLOPT_URL, $get_userinfo);
    curl_setopt($user_ch, CURLOPT_SSL_VERIFYPEER, FALSE);
    curl_setopt($user_ch, CURLOPT_SSL_VERIFYHOST, FALSE);
    curl_setopt($user_ch, CURLOPT_RETURNTRANSFER, 1);
    $user_out = curl_exec($user_ch);
    curl_close($user_ch);

    $json_user = json_decode($user_out,true);

  //  P($json_user);
    //整理 访问微信服务器的地址 end
    /*  整理获取到用户的数据 start */
    $insert_user['user_name'] = $json_user['nickname'];
    $insert_user['user_passwd'] = $json_user['openid'];
    $insert_user['user_chief'] = $chief;
    $insert_user['sex'] = $json_user['sex'];
    $insert_user['phone'] = '';
    $insert_user['user_pic'] = $json_user['headimgurl'];
    $insert_user['country'] = $json_user['country'];
    $insert_user['province'] = $json_user['province'];
    $insert_user['city'] = $json_user['city'];
    $insert_user['wx_openid'] = $json_user['openid'];
    /*  整理获取到用户的数据 end */
    //插入数据库
   // P($insert_user);
     $db_user = D('user');
     $db_user->insert($insert_user);
   // P($wx_access_token);
    return(array('wx_access_token'=>$wx_access_token,'insert_user'=>$insert_user));
}

最后获得的用户信息可以直接存入数据库。（user_chief 为判断分销的字段，可以无限极分销（法律声明只能三级分销））