How can I keep my google plus session opened after android application close?

问题

this is my first time posting here because I've never had the need before because every question I had was already answered!

The thing is that I'm trying to log in my android application with google plus but if I close my application.. I don't know how to see if the user was already signed in.. Is there any way to do check it?

For example: - You login in my application and then you go to the MainActivity instead of the login activity. - Then you don't log out, you simply close my app for.. maybe half an hour.. - After that.. you open my app again and instead go to the MainActivity again.. you are in the login activity again..

Is there any way to know if you were already signed in?

This is my login class:

import android.content.Intent;
import android.content.IntentSender;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.SignInButton;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.Scope;
import com.google.android.gms.plus.Plus;

public final class LoginGPlusFragment extends Fragment implements
        View.OnClickListener,
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener
{
    /* Request code used to invoke sign in user interactions. */
    private static final int RC_SIGN_IN = 0;

    /**
     * True if we are in the process of resolving a ConnectionResult
     */
    private boolean mIntentInProgress;

    /**
     * True if the sign-in button was clicked.  When true, we know to resolve all
     * issues preventing sign-in without waiting.
     */
    private boolean mSignInClicked;

    static GoogleApiClient mGoogleApiClient;
    SignInButton btnLogin;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        return inflater.inflate(R.layout.fragment_gplus_login, container, false);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState)
    {
        Log.d("DEBUG","onViewCreated LoginGPlusFragment");
        super.onViewCreated(view, savedInstanceState);
        if(mGoogleApiClient == null || !mGoogleApiClient.isConnected())
            mGoogleApiClient = new GoogleApiClient.Builder(getActivity())
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .addApi(Plus.API)
                    .addScope(new Scope("profile"))
                    .build();
        else
            Log.d("DEBUG","onViewCreated you're already connected");
        btnLogin = (SignInButton)view.findViewById(R.id.sign_in_button);
        btnLogin.setOnClickListener(this);
    }

    @Override
    public void onConnectionFailed(ConnectionResult result)
    {
        Log.d("DEBUG","onConnectionFailed LoginGPlusFragment");
        if (!mIntentInProgress)
        {
            if (mSignInClicked && result.hasResolution())
            {
                // The user has already clicked 'sign-in' so we attempt to resolve all
                // errors until the user is signed in, or they cancel.
                try
                {
                    result.startResolutionForResult(getActivity(), RC_SIGN_IN);
                    mIntentInProgress = true;
                } catch (IntentSender.SendIntentException e) {
                    // The intent was canceled before it was sent.  Return to the default
                    // state and attempt to connect to get an updated ConnectionResult.
                    mIntentInProgress = false;
                    mGoogleApiClient.connect();
                }
            }
        }
    }

    @Override
    public void onClick(View view)
    {
        if (view.getId() == R.id.sign_in_button && !mGoogleApiClient.isConnecting())
        {
            mSignInClicked = true;
            mGoogleApiClient.connect();
        }
    }

    @Override
    public void onResume()
    {
        super.onResume();
        Log.d("DEBUG","onResume LoginGPlusFragment");
        if(mGoogleApiClient!=null && mGoogleApiClient.isConnected())
            launchChatActivity();
        else
            Log.d("DEBUG","onResume you are disconnected");
    }

    @Override
    public void onConnected(Bundle bundle)
    {
        Log.d("DEBUG","onConnected LoginGPlusFragment");
        mSignInClicked = false;
        launchChatActivity();
    }


    private void launchChatActivity()
    {
        String accountName = Plus.AccountApi.getAccountName(mGoogleApiClient);
        Log.d("DEBUG", "Connected with google. You are "+accountName);
        btnLogin.setVisibility(View.INVISIBLE);
        Intent i = new Intent(getActivity(), ChatActivity.class);
        startActivity(i);
        getActivity().finish();
    }

    @Override
    public void onConnectionSuspended(int i)
    {
        Log.d("DEBUG","onConnectionSuspended LoginGPlusFragment");
        mGoogleApiClient.connect();
    }

    @Override
    public void onActivityResult(int requestCode, int responseCode, Intent data)
    {
        super.onActivityResult(requestCode, responseCode, data);
        Log.d("DEBUG","onActivityResult LoginGPlusFragment");

        if (requestCode == RC_SIGN_IN)
        {
            if (responseCode != getActivity().RESULT_OK)
            {
                mSignInClicked = false;
            }

            mIntentInProgress = false;

            if (!mGoogleApiClient.isConnected())
            {
                mGoogleApiClient.reconnect();
            }
        }
    }
}

Thank you very much!!

回答1:

Ok, I will answer myself.

As I still don't know if there is a way to do it automatically, I do it at the moment by saving a shared preference in the onConnected method:

@Override
public void onConnected(Bundle bundle)
{
    SharedPreferences sharedPref = getActivity().getSharedPreferences("login", Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPref.edit();
    editor.putBoolean("signed_in_with_google", true);
    editor.commit();
    Log.d("DEBUG","onConnected LoginGPlusFragment");
    mSignInClicked = false;
    launchChatActivity();
}

And i delete it in my disconnect method // Google log out

if(LoginGPlusFragment.mGoogleApiClient.isConnected())
       LoginGPlusFragment.mGoogleApiClient.disconnect();

SharedPreferences sharedPref = getSharedPreferences("login", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putBoolean("signed_in_with_google", false);
editor.commit();
returnToLoginScreen();

And then, I check in the onCreateView if my preference is true:

@Override
public void onViewCreated(View view, Bundle savedInstanceState)
{
    Log.d("DEBUG","onViewCreated LoginGPlusFragment");
    super.onViewCreated(view, savedInstanceState);
    mGoogleApiClient = new GoogleApiClient.Builder(getActivity())
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(Plus.API)
            .addScope(new Scope("profile"))
            .build();
    SharedPreferences pref = getActivity().getSharedPreferences("login", Context.MODE_PRIVATE);
    boolean signed = pref.getBoolean("signed_in_with_google", false);

    btnLogin = (SignInButton) view.findViewById(R.id.sign_in_button);
    btnLogin.setOnClickListener(this);

    if(signed)
    {
        Log.d("DEBUG","You were previously signed in with google.");
        connect();
    }
}

来源：https://stackoverflow.com/questions/29697150/how-can-i-keep-my-google-plus-session-opened-after-android-application-close