Flutter Firebase.signInWithGoogle method not found

Question

I am trying to add Google Authentication in my Flutter Application. But my Android studio is not able to find the method signInWithGoogle under Fire

Answer 1

Adding to the accepted answer, since firebase_auth version 0.12.0:

Sign-in methods now return AuthResult instead of FirebaseUser. Retrieve the FirebaseUser using the user property of AuthResult.

So the actual correct solution is:

...
    final AuthResult authResult = await _auth.signInWithCredential(credential);
    final FirebaseUser user = authResult.user;
...

Answer 2

check out the example provided in the firebase_auth github repo https://github.com/flutter/plugins/blob/master/packages/firebase_auth/example/lib/main.dart#L70

Future<String> _testSignInWithGoogle() async {
    final GoogleSignInAccount googleUser = await _googleSignIn.signIn();
    final GoogleSignInAuthentication googleAuth =
        await googleUser.authentication;
    final AuthCredential credential = GoogleAuthProvider.getCredential(
      accessToken: googleAuth.accessToken,
      idToken: googleAuth.idToken,
    );

    final AuthResult authResult = await _auth.signInWithCredential(credential);
    final FirebaseUser user = authResult.user;
    assert(user.email != null);
    assert(user.displayName != null);
    assert(!user.isAnonymous);
    assert(await user.getIdToken() != null);

    final FirebaseUser currentUser = await _auth.currentUser();
    assert(user.uid == currentUser.uid);

    return 'signInWithGoogle succeeded: $user';
}

Answer 3

Instead of using fireebaseauth.signInWithGoogle (which is depreciated)
use:

AuthCredential credential = GoogleAuthProvider.getCredential(
    idToken: googleSignInAuthentication.idToken,
    accessToken: googleSignInAuthentication.accessToken
);

Your code will look like this:

Future handleSign() async {
preferences = await SharedPreferences.getInstance();
setState(() {
  loading = true;
});

GoogleSignInAccount googleUser = await googleSignIn.signIn();
GoogleSignInAuthentication googleSignInAuthentication = await googleUser
    .authentication;
AuthCredential credential = GoogleAuthProvider.getCredential(
    idToken: googleSignInAuthentication.idToken,
    accessToken: googleSignInAuthentication.accessToken);
}