在另一个活动中获取 google 登录帐户

Question

I read some posts about it but i didn't find the right way for this. So here is the problem:

I have used google signin in my login activity , everything works fine. The user goes to another activity , then to a third one and then in another one. In the fourth activity i need the google signed user (actually is an activity to use Google Play Services, achievements etc.) What is the best and shorter way to get the signed in user? Do i have to make ALL the login processes again?

UPDATE:

As mentioned updated code in my activity as follow:

@Override
protected void onStart() {
    super.onStart();        
    if (!isSignedIn()) {
        signInSilently();
    }

And

private boolean isSignedIn() {
    return GoogleSignIn.getLastSignedInAccount(this) != null;
}
private void signInSilently() {
    Log.d(TAG, "signInSilently()");

    mGoogleSignInClient.silentSignIn().addOnCompleteListener(this,
            new OnCompleteListener<GoogleSignInAccount>() {
                @Override
                public void onComplete(@NonNull Task<GoogleSignInAccount> task) {
                    if (task.isSuccessful()) {
                        Log.d(TAG, "signInSilently(): success");
                        onConnected(task.getResult());
                    } else {
                        Log.d(TAG, "signInSilently(): failure", task.getException());
                        onDisconnected();
                    }
                }
            });

as i dont want to have a new login (buttons etc). First i think that user should be connected. But even if he is disconnected, signInSilently() should connect again the user.

My final problem is that i get a null object exception in:

mLeaderboardsClient.submitScore(getString(R.string.leaderboard_leaderboard),



private void onConnected(GoogleSignInAccount googleSignInAccount) {
    Log.d(TAG, "onConnected(): connected to Google APIs");

    mAchievementsClient = Games.getAchievementsClient(this, googleSignInAccount);
    mLeaderboardsClient = Games.getLeaderboardsClient(this, googleSignInAccount);
    mEventsClient = Games.getEventsClient(this, googleSignInAccount);
    mPlayersClient = Games.getPlayersClient(this, googleSignInAccount);

as i can understand because of NO GOOGLE user. What else i have to do so get my google signedin user?

Answer 1

You can use this function to check if the user is logged in or not.

private boolean isSignedIn() {
  return GoogleSignIn.getLastSignedInAccount(context) != null;
}

https://developers.google.com/android/reference/com/google/android/gms/auth/api/signin/GoogleSignIn

public static GoogleSignInAccount getLastSignedInAccount (Context context)

Gets the last account that the user signed in with.

Returns: GoogleSignInAccount from last known successful sign-in. If user has never signed in before or has signed out / revoked access, null is returned.

If it returns null just relogin the user. that's all.