save variables after quitting application?

android variables quit
Stupe picture Stupe · Jul 27, 2012 · Viewed 39.9k times · Source

I want some variables to be saved, when I shut down my app and to load them after opening the app (for statistics in a game)

How can I do this?

EDIT: Here my code:

TextView test1;
String punkte = "15";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    SharedPreferences save = getSharedPreferences(punkte, 0);
    save.edit().putString("score", punkte);

    SharedPreferences load = getSharedPreferences(punkte, 0);
    String points = load.getString("score", "0");

    test1 = (TextView) findViewById(R.id.test1);
    test1.setText(points);

    }

Answer

Mxyk picture Mxyk · Jul 27, 2012

You should be using SharedPrefences. They are quite simple to use and will store the variables in the application data. As long as the user never hits "Clear Data" in the settings for your application, they will always be there.

Here is a code sample.

To access variables:

SharedPreferences mPrefs = getSharedPreferences("label", 0);
String mString = mPrefs.getString("tag", "default_value_if_variable_not_found");

To edit the variables and commit (store) them:

SharedPreferences.Editor mEditor = mPrefs.edit();
mEditor.putString("tag", value_of_variable).commit();

Make sure both "tag" fields match!

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