1.申请测试账号,并配置一系列东西,这个很简单略
2.重要!!!
配置授权网页,这关系到跳转.后面再提

image.png

3.先上链接

https://open.weixin.qq.com/connect/oauth2/authorize
?appid= 微信的appid
&redirect_uri=跳转的URL 要在前面授权网页域名下的地址
&response_type=code
&scope=snsapi_base/snsapi_userinfo 后者需要提供用户信息（授权）
&state=123#wechat_redirect

这里我专门把长链接切开,看的清楚
4.在代码中读取,这里我用PHP做为demo//我也不知道 毕竟不是我写的...

 public function index()
    {
        // 1.用户同意授权后,获得code
        $code = $_GET['code'];
        // 用户授权时获取到到状态
        $state = $_GET['state'];

        $appid = C('TEACHER_APPID');
        $appsecret = C('TEACHER_APPSECRET');

        if (empty($code)) {
            //$this->error('授权失败');
            echo '<h2 style="text-align:center;">授权失败</h2>';
            exit;
        }

        // 2.通过code来获取网页授权的access_token
        $access_token_url = 'https://api.weixin.qq.com/sns/oauth2/access_token?appid=' . $appid . '&secret=' . $appsecret . '&code=' . $code . '&grant_type=authorization_code ';
        $access_token = json_decode(file_get_contents($access_token_url));
        if (isset($access_token->errcode)) {
            //echo '<h1>错误:</h1>' . $access_token->errcode;
            //echo '<br/><h2>错误信息:</h2>' . $access_token->errmsg;
            //exit;
            //$this->error('请重新授权登录');
            echo '<h2 style="text-align:center;">请重新授权登录</h2>';
            exit;
        }

        // 3.由于access_token拥有较短的有效期,刷新可以重置有效期,
        $refresh_token_url = 'https://api.weixin.qq.com/sns/oauth2/refresh_token?appid=' . $appid . '&grant_type=refresh_token&refresh_token=' . $access_token->refresh_token;
        $refresh_token = json_decode(file_get_contents($refresh_token_url));
        if (isset($refresh_token->errcode)) {
            //echo '<h1>错误:</h1>' . $refresh_token->errcode;
            //echo '<br/><h2>错误信息:</h2>' . $refresh_token->errmsg;
            //exit;
            //$this->error('请重新授权登录');
            echo '<h2 style="text-align:center;">请重新授权登录</h2>';
            exit;
        }

        // 4.获取用户信息
        $user_info_url = 'https://api.weixin.qq.com/sns/userinfo?access_token=' . $refresh_token->access_token . '&openid=' . $refresh_token->openid . '&lang=zh_CN';
        $user_info = json_decode(file_get_contents($user_info_url));
        if (isset($user_info->errcode)) {
            //echo '<h1>错误:</h1>' . $user_info->errcode;
            //echo '<br/><h2>错误信息:</h2>' . $user_info->errmsg;
            //exit;
            //$this->error('请重新授权登录');
            echo '<h2 style="text-align:center;">请重新授权登录</h2>';
            exit;
        }

        if (empty($user_info)) {
            echo '<h2 style="text-align:center;">获取用户信息失败,请重新登录</h2>';
            exit;
        }

        // 获取微信用户信息
        $data = array(
            'openid' => $user_info->openid,
            'nickname' => $user_info->nickname,
            'sex' => $user_info->sex,
            'city' => $user_info->city,
            'province' => $user_info->province,
            'country' => $user_info->country,
            'headimgurl' => $user_info->headimgurl,
            'type' => 0,
            'modified' => time(),
        );
        echo $refresh_token;
        dump($data);
        dump($user_info);
    }

Thanks.