Firebase 身份验证颤动

Question

对于已登录的用户

 Future<String> signInWithGoogle() async {
        final GoogleSignInAccount googleSignInAccount = await googleSignIn.signIn();
        final GoogleSignInAuthentication googleSignInAuthentication =
        await googleSignInAccount.authentication;
    
        final AuthCredential credential = GoogleAuthProvider.getCredential(
          accessToken: googleSignInAuthentication.accessToken,
          idToken: googleSignInAuthentication.idToken,
        );
    
        final AuthResult authResult = await _auth.signInWithCredential(credential);
    
        final FirebaseUser user = authResult.user;
        assert(!user.isAnonymous);
        assert(await user.getIdToken() != null);
        final FirebaseUser currentUser = await _auth.currentUser();
        assert(user.uid == currentUser.uid);
        if(authResult.additionalUserInfo.isNewUser == true){
          InsertNewUserDetails(user.displayName,user.email,user.photoUrl,user.phoneNumber);
        }
        if(authResult.user != null){
          email = user.email;
          name = user.displayName;
          imageUrl =user.photoUrl;
          globalInstance.isLoggedIn = true;
          print(globalInstance.isLoggedIn);
    
        }
        return 'signInWithGoogle succeeded: $user';
      }

第一次登录登录页面检查是否已登录帐户

class MyApp extends StatelessWidget {
  @override
  String strinbggg;
  Widget build(BuildContext context) {
    // TODO: implement build
    return MaterialApp(
      home: Scaffold(
        backgroundColor: Colors.teal,
        body: StreamBuilder<FirebaseUser>(
          stream: FirebaseAuth.instance.onAuthStateChanged,
          builder: (BuildContext context, snapshot) {
            if (snapshot.hasData && (!snapshot.data.isAnonymous)) {
//             return Text('${snapshot.hasData}');
              return Homepage();
            } else {
//              return SafeArea(
//                maintainBottomViewPadding: true,
//                  child: Text('aasdasdfasfdh : ${snapshot.data.email}',style: TextStyle(color: Colors.black54),));
              return LoginPage();
            }
          },
        ),
      ),
    );
  }
}

当第一次使用谷歌登录时，它的工作原理。当我关闭应用程序并重新启动时，它会很好地重定向到主页，但用户个人资料详细信息（如 displayName 、电子邮件）返回空值

signInwithgoogle() 用于首次登录，将用户详细信息存储在 firestore 中，并从此处设置用户详细信息

MyApp 是应用程序的起点，将检查用户是否已登录

Answer 1

我建议，你检查用户是否已经登录或没有使用该方法

bool isSignedIn = await _googleSignIn.isSignedIn();

如果用户已登录，则使用获取凭据

user = await _auth.currentUser();

当您启动应用程序时。如果您没有登录，请显示登录页面。任何示例都如下所示

final auth = FirebaseAuth.instance;

class MyApp extends StatelessWidget {
  @override
  String strinbggg;
  Widget build(BuildContext context) {

      return MaterialApp(
      home:  (_isSignedIn() == true ? new Homepage() : new LoginPage()));
   }
   bool _isSignedIn() async {
      bool isSignedIn = await _googleSignIn.isSignedIn();
      if(isSignedIn){
          GoogleSignInAccount user = await auth.currentUser;
          //You can store this in your state.
     }
      return !(user == null && auth.currentUser == null);
   }
}

请注意，这是一个在编辑器中编写的代码，未经测试，您必须进行调整。