How to clear old preferences when updating Android app?

Question

I have an app on the Google Play market. For various reasons that I won\'t bother going into, I have changed the type of some of my preferences. For example a preference t

Answer 1

Store version code in default SharedPreferences AND store your others preferences in version specified file , when the version change you can find your old version code and you can have your old preference file and update the new version by old data

int versionCode=0,oldVersion;
    try
    {
        versionCode = getPackageManager().getPackageInfo(getPackageName(), 0).versionCode;
    }
    catch (PackageManager.NameNotFoundException e)
    {}
    SharedPreferences prefs =getSharedPreferences("MyPref" + versionCode, Context.MODE_PRIVATE);
    SharedPreferences prefsDefault = PreferenceManager.getDefaultSharedPreferences(MainActivity.this);  


    oldVersion=prefsDefault.getInt("OldVersion",0);


    if (oldVersion!=versionCode)
    {
        if (oldVersion>0)
        {
            // ToDo Update Preferences
            String oldPrefsKey="MyPref" + oldVersion;
            SharedPreferences oldPrefs =context.getSharedPreferences(oldPrefsKey, Context.MODE_PRIVATE);
            SharedPreferences.Editor pEdit=prefs.edit();
            pEdit.putBoolean("clock24",oldPrefs.getBoolean("clock24",false));
            pEdit.putBoolean("show_clock",oldPrefs.getBoolean("show_clock",true));
            pEdit.commit();
            oldPrefs.edit().clear().commit();
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                deleteSharedPreferences(oldPrefsKey);
            } else {
                try {
                    File oldFile=new File(getCacheDir().getParent() + "/shared_prefs/"+oldPrefsKey+".xml");
                    oldFile.delete();
                } catch (Exception e) {

                }
            }

        }
        prefsDefault.edit().putInt("OldVersion",versionCode).commit();




    }