New Preferences not loading when back button is pressed

I have this preferences class (below) that saves two ListPreferences, but if the ListPreferences are changed and the back button is pressed, the changes don't take affect unless the application is restarted. Did I miss something? Have been looking everywhere, but just can't seem to find an answer the fits or works. Please help.

    public class Preferences extends PreferenceActivity {

      @Override
      public void onCreate(Bundle savedInstanceState){
           super.onCreate(savedInstanceState);
           addPreferencesFromResource(R.xml.preferences);
           }

      @Override
      public void onPause() {
           super.onPause();
           }

      @Override
      public void onResume() {
           super.onResume();
           }
      }

Application Code

 public class Quotes extends Activity implements OnClickListener {

 ProgressDialog dialog;
 private WebView webview;

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

      SharedPreferences SP = PreferenceManager.getDefaultSharedPreferences(getBaseContext());

      String q = SP.getString("appViewType","http://www.google.com");
      String c = SP.getString("appRefreshRate","20");

      webview = (WebView) findViewById(R.id.scroll);
      webview.getSettings().setJavaScriptEnabled(true);
      webview.setWebViewClient(new QuotesWebView(this));
      webview.loadUrl(q);

      ScheduledExecutorService timer = Executors.newSingleThreadScheduledExecutor();
      timer.scheduleAtFixedRate(new Runnable() {

      @Override
      public void run() {
           webview.reload();
           }

      }, 10, Long.parseLong(c),TimeUnit.SECONDS);

      findViewById(R.id.refresh).setOnClickListener(this);
 }

      @Override
      public void onPause(){
           super.onPause();
           }

      @Override
      public void onResume(){
           super.onResume();
           }

      public void onClick(View v){
           switch(v.getId()){
                case R.id.refresh:
                webview.reload();
           break;
      }
 }


 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
      MenuInflater inflater = getMenuInflater();
      inflater.inflate(R.menu.menu, menu);

      MenuItem about = menu.getItem(0);
      about.setIntent(new Intent(this, About.class));

      MenuItem preferences = menu.getItem(1);
      preferences.setIntent(new I开发者_开发百科ntent(this, Preferences.class));

      return true;

      }

 }   

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You need to somehow reload your preferences when the preferences activity finishes. I thought Dirol's suggestion of loading them in onResume() instead of onCreate() was excellent; have you tried it? Or am I misunderstanding the problem as well.

In my own case, I launched the preferences activity with startActivityForResult() and then on the activity result callback, I reloaded the preferences.

Code snippets:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
      case MENU_PREFERENCES:
        Intent intent = new Intent().setClass(this, CalcPreferences.class);
        startActivityForResult(intent, MENU_PREFERENCES);
        break;
      default: return super.onOptionsItemSelected(item);
    }
    return true;
}

@Override
protected void onActivityResult(int req, int result, Intent data) {
    switch( req ) {
      case MENU_PREFERENCES:
        SharedPreferences sp =
          PreferenceManager.getDefaultSharedPreferences(this);
        updatePreferences(sp);
        break;
      default:
        super.onActivityResult(req, result, data);
        break;
    }
}

@Override
protected void updatePreferences(SharedPreferences sp) {
    super.updatePreferences(sp);
    keyclick = sp.getBoolean("keyclick", keyclick);
}

Anyway, this is what works for me. I may try moving my updatePreferences() call to onResume() myself to see if that works too.

---

Try overriding the onBackPressed() method.

If your "Up" button (top left <-) provides the correct result, then you can set the Back button to behave like the Up button.

@Override
public void onBackPressed() {
    super.onBackPressed();
    NavUtils.navigateUpFromSameTask(this);
}

---

You load preferences only on onCreate() method. That method called only when a fresh activity starts up. The addPreferencesFromResource inflates the xml file into the preferences, so you only get the info, which is already has been stored in the xml at the moment addPreferencesFromResource was called, not after.

Try to move that method to onResume. But watch for the memory leak. I don't know exactly what the addPreferencesFromResource do, but from the documentation - I would be very suspicious about that method activity.

---

I had the same problem and solved it as follows:

The main activity class implements OnSharedPreferenceChangeListener:

public class Activity_name extends Activity implements OnSharedPreferenceChangeListener  {
    ...
}

Inside the main activity class the onSharedPreferenceChanged is run whenever a preference entry changes. I simply update all my variables from the preferences as i did in onCreate:

@Override
public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
    <read all preferences as you did in onCreate()>
}

This does the trick and I hope it saves you some time in searching for a solution.

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I've had the same problem... Try to create preference instance and load its data in every class and every activity where you need it. It worked for me...Hope it helps.

---

You will need to reload your view or whatever object which uses those preferences, preferably when preference activity closes.

Preference activities do not change nothing but an internal file with your preferences(key=value list). When it is changed, preferenceActivity calls onPreferenceChaged() and nothing more. It doesn't refresh your stuff by itself. You need to reload prefs and to reuse them in onResume() method or equivalent.