升级google_sign_in至6.0.0后Google登录功能异常求助

问题根源 #

1. 重复登录触发冲突：signIn方法里同时调用signInSilently()和await _googleSignIn.signIn()，两次登录流程会导致状态混乱。
2. authHeaders在web端的兼容性变化：6.x版本中web端的user.authHeaders获取逻辑有变更，直接使用会触发请求错误。

解决方案 #

1. 修复重复登录逻辑

把signInSilently()移到页面初始化阶段执行，避免和主动登录流程冲突：

@override
void initState() {
  super.initState();
  // 页面初始化时尝试静默登录
  signInSilently();
}

void signInSilently() {
  _googleSignIn.onCurrentUserChanged.listen((GoogleSignInAccount? account) {
    print('signInsilently log!!');
    print(account);
    if (account != null) {
      _handleGetContact(account);
    }
  });

  _googleSignIn.signInSilently();
}

Future<void> signIn() async {
  try {
    var googleSignInAccount = await _googleSignIn.signIn();
    print(googleSignInAccount);
    if (googleSignInAccount != null) {
      await _handleGetContact(googleSignInAccount);
    }
  } catch (e) {
    print('登录出错: $e');
  }
}

2. 调整People API请求的header构建方式

不再依赖user.authHeaders，改为通过user.authentication获取accessToken后手动构建请求头：

Future<void> _handleGetContact(GoogleSignInAccount user) async {
  try {
    final GoogleSignInAuthentication auth = await user.authentication;
    final String accessToken = auth.accessToken!;

    final http.Response response = await http.get(
      Uri.parse('https://people.googleapis.com/v1/people/me/connections'
          '?requestMask.includeField=person.names'),
      headers: {
        'Authorization': 'Bearer $accessToken',
      },
    );
    if (response.statusCode != 200) {
      print('People API ${response.statusCode} response: ${response.body}');
      return;
    }
    final Map<String, dynamic> data = json.decode(response.body) as Map<String, dynamic>;
    // 此处处理返回的联系人数据
  } catch (e) {
    print('获取联系人出错: $e');
  }
}

3. 额外检查

确保web项目的index.html中已正确引入Google GSI脚本：

<script src="https://accounts.google.com/gsi/client" async defer></script>

内容的提问来源于stack exchange，提问作者K m.k