如何检查用户是否已经在 google auth 中登录。 在安卓中

Question

I'm a new android developer and a student. I'm having difficulty of if the user is already login in my app. I will show some of my codes. I greatly appreciate for the help and answer.

Login.java

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.login);

    OptionalPendingResult<GoogleSignInResult> opr = Auth.GoogleSignInApi.silentSignIn(mGoogleApiClient);

    if(opr.isDone()) {
        Log.d(TAG,"Got cached sign-in");
        GoogleSignInResult result = opr.get();
        handleSignInResult(result);
    } else {
        SignInButton mGoogleSignInButton = (SignInButton) findViewById(R.id.sign_in_button);
        mStatusView = (TextView) findViewById(R.id.status_text);
        mGoogleSignInButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                switch (v.getId()) {
                    case R.id.sign_in_button:
                        signInWithGoogle();
                }
            }
        });
    }
}
 private void signInWithGoogle(){
    if(mGoogleApiClient != null) {
        mGoogleApiClient.disconnect();
    }

    GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN).requestEmail().build();
    mGoogleApiClient = new GoogleApiClient.Builder(this).addApi(Auth.GOOGLE_SIGN_IN_API,gso).build();

    final Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
    startActivityForResult(signInIntent, RC_SIGN_IN);
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode,resultCode,data);

    if(requestCode == RC_SIGN_IN) {
        GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
        handleSignInResult(result);
    }
}



private void handleSignInResult(GoogleSignInResult result) {
    Log.d(TAG, "handleSignInResult:" + result.isSuccess());
    if(result.isSuccess()) {
        GoogleSignInAccount account = result.getSignInAccount();
        mStatusView.setText(getString(R.string.signed_in_fmt, account.getDisplayName()));
        //TODO: Start another explicit intent here. but this time, start MainActivity
        Intent intent = new Intent(Login.this , MainActivity.class);
        startActivity(intent);
        finish();

    } else {

    }
}

where did i go wrong ?

Answer 1

For Google Login check whether user is signed in or not:

if (mGoogleApiClient != null && mGoogleApiClient.isConnected()) {
   // User is signed in.
   // ...
} else {
   // User is not signed in. 
   // Perform your operation.
}

Answer 2

GoogleApiClient mGoogleApiClient is deprecated now! So according doc

   // Check for existing Google Sign In account, if the user is already signed in
// the GoogleSignInAccount will be non-null.
GoogleSignInAccount account = GoogleSignIn.getLastSignedInAccount(this);
updateUI(account);

For example:

 if (GoogleSignIn.getLastSignedInAccount(context) == null) {
            Log.d(TAG_SIGN_FLOW, "User is not signed in, so make login in")

            val signInOptions: GoogleSignInOptions = GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestEmail()
                .requestScopes(Scope(DriveScopes.DRIVE_FILE))
                .build()
            startActivityForResult(GoogleSignIn.getClient(this.requireActivity(), signInOptions).signInIntent, REQUEST_CODE_SIGN_IN)
        } else {
            Log.d(TAG_SIGN_FLOW, "User has already been login")
        }

Answer 3

Assuming that you are checking authentication status from any Activity for eg Main Activity (Incase fragment get a singleton instance of your context from any activity which it is triggered from).

GoogleApiClient mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(Plus.API)
                .addScope(Plus.SCOPE_PLUS_LOGIN)
                .build();

    if (mGoogleApiClient.isConnected()) {
            //Todo
        }
    }

Answer 4

I know it has been 6 years already but I can try to help. To check whether user is logged in and immediately open the MainActivity override the on Start method

   @Override
    protected void onStart() {
    super.onStart()

    FirebaseAuth auth = FirebaseAuth.getInstance();
    FirebaseUser fUser = auth.getCurrentUser();

    if (fUser != null){
     startActivity(new Intent(LoginActivity.this, MainActivity.class));
     }


  }

The above code will do the trick. Happy coding:)

Answer 5

Made change in below code-

Maintain a boolean variable in sharedPreferance and will work for you.

SharedPreferences sharedPreferences;
    SharedPreferences.Editor editor;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.login);

sharedPreferences =getSharedPreferences(getPackageName(), MODE_PRIVATE);
        editor = sharedPreferences.edit();

if(sharedPreferences.getBoolean("isLogin",false))
{
        Intent intent = new Intent(Login.this , MainActivity.class);
        startActivity(intent);
        finish();
}

    OptionalPendingResult<GoogleSignInResult> opr = Auth.GoogleSignInApi.silentSignIn(mGoogleApiClient);

    if(opr.isDone()) {
        Log.d(TAG,"Got cached sign-in");
        GoogleSignInResult result = opr.get();
        handleSignInResult(result);
    } else {
        SignInButton mGoogleSignInButton = (SignInButton) findViewById(R.id.sign_in_button);
        mStatusView = (TextView) findViewById(R.id.status_text);
        mGoogleSignInButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                switch (v.getId()) {
                    case R.id.sign_in_button:
                        signInWithGoogle();
                }
            }
        });
    }
}
 private void signInWithGoogle(){
    if(mGoogleApiClient != null) {
        mGoogleApiClient.disconnect();
    }

    GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN).requestEmail().build();
    mGoogleApiClient = new GoogleApiClient.Builder(this).addApi(Auth.GOOGLE_SIGN_IN_API,gso).build();

    final Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
    startActivityForResult(signInIntent, RC_SIGN_IN);
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode,resultCode,data);

    if(requestCode == RC_SIGN_IN) {
        GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
        handleSignInResult(result);
    }
}



private void handleSignInResult(GoogleSignInResult result) {
    Log.d(TAG, "handleSignInResult:" + result.isSuccess());
    if(result.isSuccess()) {
        GoogleSignInAccount account = result.getSignInAccount();
        mStatusView.setText(getString(R.string.signed_in_fmt, account.getDisplayName()));
        //TODO: Start another explicit intent here. but this time, start MainActivity

        sharedPreferences.edit().putBoolean("isLogin",true).apply();
        Intent intent = new Intent(Login.this , MainActivity.class);
        startActivity(intent);
        finish();

    } else {

    }
}