Question

I want to clear all the sharedpref i put on my first activity and delete it on 2nd activity. But the clear function is not working.. here is my code

public class MyActivity extends Activity implements View.OnClickListener {
    /**
     * Called when the activity is first created.
     */

    public static final String PREFS_NAME = "ResumePrefs";

    SharedPreferences settings;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        ((Button)findViewById(R.id.button)).setOnClickListener(this);

    }

    @Override
    protected void onResume() {
        try{
            Toast. makeText(this,settings.getString("answer_id",""),Toast.LENGTH_LONG).show();
        }catch (Exception e){
            Toast.makeText(this,e.toString(),Toast.LENGTH_LONG).show();
        }
        super.onResume();
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.button:
                 settings = getSharedPreferences(PREFS_NAME, 1);
                SharedPreferences.Editor editor = settings.edit();
                editor.putString("answer_id", "This is a test");
                editor.commit();
                     Intent intent = new Intent(this,destroyPref.class);
                startActivity(intent);
                break;
        }
    }
}

and my2nd activty:

public class destroyPref extends Activity {
    public static final String PREFS_NAME = "ResumePrefs";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.destroy);

    }

    @Override
    public void onBackPressed() {
        SharedPreferences settings = this.getSharedPreferences(PREFS_NAME,1);
        settings.edit().clear();
        settings.edit().commit();
        super.onBackPressed();
    }

    @Override
    protected void onResume() {
        SharedPreferences settings = this.getSharedPreferences(PREFS_NAME,1);
        settings.edit().clear();
        settings.edit().commit();
        super.onResume();
    }
}

Once i pressed the back button i will go back to the main activity and expect that the preference value is cleared, unless i pressed again the button. I tried bot backpress and resume but still the sharedpref value is still there.. Am i missing something? Thanks.

Answer 1

Try with this :

SharedPreferences.Editor editor = settings.edit();
editor.clear();
editor.commit();

Thanks.