using onSaveInstanceState(Bundle ..) and onRestoreInstanceState(Bundle ..)
was really good and work, but it is working when click Turn off button on Emulator.
Now, i want to save state and restore the saved data when below button used:
I think it is possible to use OnPause() OR oOnStop(), if i am right, How to use it,
it will be enough to show me Java source of saving one boolean variable, and restore it,
Thanks.
I had problems reading sharedPreferences after PowerOff when they were stored using onPause. The workaround was to call clear() first.
public static final String PREFS_NAME = "MyPrefsFile";
protected void onPause(){
super.onPause();
SharedPreferences settings = getSharedPreferences(PREFS_NAME,0);
SharedPreferences.Editor editor = settings.edit();
// Necessary to clear first if we save preferences onPause.
editor.clear();
editor.putInt("Metric", mMetric);
editor.commit();
}
I would use onPause(), as onStop() is not guaranteed to be called. See the application fundamentals for details on the lifecycle.
To save and restore a boolean, I would use SharedPreferences. There is a code example on the data storage page that shows how to save and restore a boolean. They use onCreate() and onStop(), but I would use onResume() and onPause(), for the reasons I have already mentioned.
the example :
public class Calc extends Activity {
public static final String PREFS_NAME = "MyPrefsFile";
@Override
protected void onCreate(Bundle state){
super.onCreate(state);
. . .
// Restore preferences
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
boolean silent = settings.getBoolean("silentMode", false);
setSilent(silent);
}
@Override
protected void onStop(){
super.onStop();
// We need an Editor object to make preference changes.
// All objects are from android.context.Context
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putBoolean("silentMode", mSilentMode);
// Commit the edits!
editor.commit();
}
}
See Step 7 and Step 8 in the Android SDK notepad tutorial part 3. for an example saving the state to a sqlite DB (using a previously defined db-helper class.)
In that case you have no other option than making your state persistant in one of the ways described in Android DevGuide
you can just override onPause() in your activity say activtyA when you are navigating to another activity say activityB and override onResume() when u come back to the activityA.
