SharedPreferences not reset on reinstall

Question

I have a SharedPreference that counts the amount of launches of my App. I expect this to be 0, when I install my app. Nevertheless it is 14. The same strange behaviour I observe with my database, that already exists on a fresh install.

I didn't intent to recycle my app data (like in the Google Cloud). On my device in the account settings the app-data sync is on. If I turn it off, and make a reinstall I observe the same behaviour.

Anyone has every observed such a behaviour? Is there any way to prevent recycling old data and force a proper install?

Could this be because of the "Auto Backup" feature introduced in Android Marshmallow? [https://developer.android.com/guide/topics/data/autobackup.html](https://developer.android.com/guide/topics/data/autobackup.html) — Mauin, Jan 23 '17 at 14:46
that's it! A lot of hair pulling for a single line of code ... — Anthea, Jan 23 '17 at 14:50

score 14 · Accepted Answer · answered Jan 23 '17 at 15:10

14

In Android Marshmallow Google introduced the "Auto Backup" feature which is turned on by default if your targetSdkVersion is >=23.

This will back up your database and SharedPreferences by default and restore it when you re-install the application. To turn this feature off you have to add android:allowBackup="false" to your AndroidManifest.xml.

More info here: Auto Backup for Apps

answered Jan 23 '17 at 15:10

Mauin

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For those who don't know which tag to add, it should be added to the application tag. – K.Amanov May 26 '21 at 11:12

score 0 · Answer 2 · edited May 23 '17 at 12:02

0

Review your code in AndroidManifest on tag application if it has android:allowBackup="false". If you don't have (by default it's true), your app participates on android backup and restore infrastructure and can happen exactly what you say.

More information in this post: What is "android:allowBackup"?

edited May 23 '17 at 12:02

Community

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answered Jan 23 '17 at 14:59

Neonamu

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score 0 · Answer 3 · edited May 23 '17 at 10:29

This needs to be handled from app side regarding shared Prefs.

Created a shared preference helper class and in the helper class have the below condition.

private static String SHARED_PREFS_VERSION = "SharedPrefsVersion"; // In this save the version of current shared Prefs.

void SharedPrefsHelper() {

    if( BuildConfig.Version > getSharedPrefsVersion() ) {

        SharedPreferences.Editor editor = prefs.edit(); editor.clear(); // Clear all the shared Prefs and update the current version.

        SetSharedPrefsVersion(BuildConfig.Version);

    }
}

For further reference look at :

https://stackoverflow.com/a/12381061/7364024

SharedPreferences not reset on reinstall

3 Answers3