Question

I need some help with an android project I am working on. I am trying to use switch preferences to send a certain text. Basically, it the user switches the switch from off to on, I want the phone to send a text saying “on”. Then when the user turns the switch from on to off, it sends a text saying “off”. All I need is to be able to see what the current state of the switch is and then if it’s off, call a “turn on” method and vice-versa.

I’ve never asked a question like this, so I don’t really know what part of my code to post.(If asked, I can post most of my code.) I think it has something to do with the onPreferenceChangeListener, but I’m not sure how to implement it. Any ideas?

Edit: Here is the main activity class:

public class MainActivity extends PreferenceActivity implements OnSharedPreferenceChangeListener {

public static final String KEY_ROOM1_SWITCH = "switch_room_1";

private SwitchPreference mSwitchPreference1;

public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
//This is a sample of one of 4 switches that are being used. They are all basically the same, but with different variables
    if (key.equals(KEY_ROOM1_SWITCH)) {
        boolean checkedornot1;
        SharedPreferences myPreference=PreferenceManager.getDefaultSharedPreferences(this);
        checkedornot1 = myPreference.getBoolean("switch_room_1", false);
        if (checkedornot1 = true)
        mSwitchPreference1.setChecked(true);
        else
        mSwitchPreference1.setChecked(false);
    }
  }
}

Do I need to grab the value that is stored in the shared preferences and make my choice based on that? or is there something else I am missing?

Answer 1

1. Edit your class that extends PreferenceActivity and add the private variable: private OnSharedPreferenceChangeListener listener;

2. Create and register your listener within the onResume method:

     public void onResume() {
     super.onResume();
     listener = new OnSharedPreferenceChangeListener() {
       public void onSharedPreferenceChanged(SharedPreferences sp, String key) {
         if (key.contains("your switchpreference key name")
         if (sp.getBoolean("your switchpreference key name",false) {
           sendOnSMS();
         } else {
           sendOffSMS();
         }
     }
     PreferenceManager.getDefaultSharedPreferences(this).registerOnSharedPreferenceChangeListener(listener);
   }
   

3. Unregister your listener within the onPause method:

   public void onPause() {
     super.onPause();
     PreferenceManager.getDefaultSharedPreferences(this).unregisterOnSharedPreferenceChangeListener(listener);
   }
   

4. Implement the sendOnSMS and sendOffSMS methods.