背景

之前每次写到获取openid 就觉得特别麻烦，网上很多代码段会把一部分功能分开写，确实相对合理，但是对于复制粘贴代码来说依赖越少越方便，所以根据自己的经验做了一个极简的复用代码

前置条件

1.公众号已认证，否则会出现“Scope 参数错误或没有 Scope 权限”
2.公众号后台设置安全域名
【公众号设置】=》【功能设置】=》【JS接口安全域名
】&【网页授权域名】

代码

前端

getOpenId(){
  const code = getUrlParam('code')  // 截取路径中的code,
  if (code == null || code === '' || code === false) {
    const local = window.location.href
    let appid='<公众号appid>'
    window.location.href = 'https://open.weixin.qq.com/connect/oauth2/authorize?appid='+appid+'&redirect_uri=' + encodeURIComponent(local) + '&response_type=code&scope=snsapi_base&state=1#wechat_redirect';
  } else {
      let that=this;
      axios.post('/index/active/getUserInfo?code='+code).then((r)=>{
        console.log(r.data)
      })
  }
}

后端

此处以php 为例

public function getUserInfo(){
    $appid = '<公众号appid>';
    $secret = '<公众号secret>';
    $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);
    $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);
    $user_obj = json_decode($res,true);
    $_SESSION['user'] = $user_obj;
    return json($user_obj);
}