CODEWITHSUNDEEP
javaandroidsharedpreferences
janDe
janDe

Reputation: 43

When leave the application, SharedPreferences must be deleted

I have a SharedPreferences that activates interstitial after every third action within the application. I want SharedPreferences to clear the settings when a user leaves the application so that interstitial can load after every application startup. Please help.

    SharedPreferences admob = getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = admob.edit();

    // Save counter value back to SharedPreferences
    editor.putInt(COUNTER_INTERSTITIAL_ADS, mAdCounter);
    editor.apply();

Upvotes: 0

Views: 1312

Answers (5)

Sumit Shukla
Sumit Shukla

Reputation: 4514

Put this dependency in your build.gradle file:

implementation "android.arch.lifecycle:extensions:*"

Then in your Application class, use this:

public class MyApplication extends Application implements LifecycleObserver {

    @Override
    public void onCreate() {
        super.onCreate();
        ProcessLifecycleOwner.get().getLifecycle().addObserver(this);
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
    private void onAppDestroyed() {
       //Clear data here
       SharedPreferences pref = getSharedPreferences(PREF_ID, Context.MODE_PRIVATE);
       pref.edit.clear().apply();
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_START)
    private void onAppForegrounded() {
        Log.d("MyApp", "App in foreground");
    }
}

Update your AndroidManifest.xml file:

<application
    android:name=".MyApplication"
    ....>
</application>

Upvotes: 1

ישו אוהב אותך
ישו אוהב אותך

Reputation: 29814

I have a SharedPreferences that activates interstitial after every third action within the application. I want SharedPreferences to clear the settings when a user leaves the application so that interstitial can load after every application startup. Please help.

Instead thinking backward and trying to clean up the SharedPreferences at the end of your Application, why don't you just reset the SharedPreferences in startup? It's more cleaner solution for your case.

You can't depend on onDestroy() method to clean up the SharedPreferences because there's no guarantee that it will be called when the application is terminated.

So, you can solve the problem easily by reset the SharedPreferences when you start your related Activity:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    ...

    SharedPreferences pref = getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = pref.edit();
    // reset the counter
    editor.putInt(COUNTER_INTERSTITIAL_ADS, 0);
    editor.apply();

    ...

}

Upvotes: 0

user8136453
user8136453

Reputation: 1

protected void onDestroy() {
    super.onDestroy();
    SharedPreferences admob = getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = admob.edit();
    editor.clear();
    editor.apply();  // or editor.commit() if on older API versions
}

Upvotes: 0

Shalu T D
Shalu T D

Reputation: 4039

Put your cleanup(Shared Preferences Cleanup) code in the onDestroy() method, this is the last method that is called before an activity finally closes. For all the information on the Android activity life cycle have a look at the Android Documentation for: Activity Lifecycle.

Sample Code:

SharedPreferences pref = getSharedPreferences(PREF_ID, Context.MODE_PRIVATE);
pref.edit.clear().apply();

Upvotes: 2

user11876874
user11876874

Reputation:

Put your code on the onDestroy() as @janDe said. Indeed it is the last method that gets called before a activity is "destroyed". The code to delete all of your shared preferences is this:

SharedPreferences pref = getSharedPreferences(PREF_ID, Context.MODE_PRIVATE);
pref.edit.clear().apply();

Basically what you do is get the preferences, go into edit mode(where you can edit the values) and say clear(). Then you can apply the changes.

Upvotes: 0

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