为什么在firebase onAuthStateChanged中完成活动时，最近的应用程序中没有屏幕截图

Question

I got a very basic splashscreen activity:

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_start);

    FirebaseAnalytics.getInstance(this);


    mAuth = FirebaseAuth.getInstance();
    mAuth.addAuthStateListener(new FirebaseAuth.AuthStateListener() {
        @Override
        public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
            FirebaseUser user = firebaseAuth.getCurrentUser();
            if (user != null) {
                FirebaseAuth.getInstance().removeAuthStateListener(this);
                startActivity(new Intent(StartActivity.this, MainActivity.class));
                finish();
            }
        }
    });
}

This splash screen opens my MainActivity . When I close this activity this is the screenshot in recent apps:

It seems like it is making a screenshot just too late, which results in this nested recent apps screenshot. This also happen on an actual device. How can I solve this weird behaviour?

Activies manifest:

<activity
    android:name="activities.StartActivity"
    android:label="@string/app_name"
    android:screenOrientation="portrait">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

<activity
    android:name="activities.MainActivity"
    android:label="@string/app_name"
    android:screenOrientation="portrait"
    android:launchMode="singleTask">
</activity>

The problem seems not the be in the launchMode . I keep having the same behaviour. Even when removing the lauchmode.

It has absolutely something to do with the callback. When starting the activity directly, there is no problem.

EDIT:

I kind a found a solution. Using a delay in starting the activity resolves it. Although a hardcoded delay isn;t that nice.

new Handler().postDelayed(new Runnable() {
    @Override
    public void run() {
        startActivity(new Intent(StartActivity.this, MainActivity.class));
        finish();
    }
},500);

EDIT 2

I do not get this behaviour when directly starting the activity. So it probably has something to do with the callback. I'm using google sign-in. It looks like some transparent activity is being closed. Could this be the Google Sign-in Activity?

Answer 1

Instead of calling finish(); you can use the android:noHistory="true" in your app manifest like this:

<activity
    android:name=".SplashActivity"
    android:noHistory="true" />

Or you can use FLAG_ACTIVITY_CLEAR_TOP in your Intent:

intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

Edit:

Why do you use the android:launchMode="singleTask" ? You should probably change this to android:launchMode="singleInstance" or remove this line completely. For more information, here is a great article about launch modes

Answer 2

I guess that your problem occur due to using launchMode singleTask without taskAffinity .

Let's change the AndroidManifest.xml

<activity
    android:name="activities.StartActivity"
    android:label="@string/app_name"
    android:screenOrientation="portrait">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

<activity
    android:name="activities.MainActivity"
    android:label="@string/app_name"
    android:screenOrientation="portrait"
    android:launchMode="singleTask"
    android:taskAffinity="your_any_string">
</activity>

hope it help!

Answer 3

I was not able to reproduce the issue you are describing, but since you say that using Handler.postDelayed() helps, try the code below.

By adding/removing the listener between onResume()/onPause() , you also avoid starting an activity when your app is in the background. Also, if the FirebaseAuth holds a list of listeners, it will keep references to activities that were already destroyed if hits the onCreate() method multiple times, for example on rotation. So you can avoid memory leaks.

private FirebaseAuth.AuthStateListener authStateListener;

@Override
protected void onResume() {
    super.onResume();

    FirebaseAnalytics.getInstance(this);

    authStateListener = new FirebaseAuth.AuthStateListener() {
        @Override
        public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
            FirebaseUser user = firebaseAuth.getCurrentUser();
            if (user != null) {
                FirebaseAuth.getInstance().removeAuthStateListener(this);
                authStateListener = null;
                startActivity(new Intent(StartActivity.this, MainActivity.class));
                finish();
            }
        }
    };
    FirebaseAuth.getInstance().addAuthStateListener(authStateListener);
}

@Override
protected void onPause() {
    super.onPause();
    if (authStateListener != null) {
        FirebaseAuth.getInstance().removeAuthStateListener(authStateListener);
    }
}