onSharedPreferenceChanged without using getDefaultSharedPreferences

问题

I'm using context.getSharedPreference instead of getDefaultSharedPreferences. Means :

SharedPreferences checkboxSetting = context.getSharedPreferences(
                                         "myPreferenceDB", Context.MODE_PRIVATE);
boolean flag = checkboxSetting.getBoolean("checkboxKey",true);

And preference.xml :

<CheckBoxPreference 
        android:key="checkBoxPrefff"
        android:title="@string/title"
        android:defaultValue="true"/>

Application setting has a checkboxpreference that I want to get the value of, checked or not checked.

Will this work?

@Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
                                                                      String key) {
    if (key.equalsIgnoreCase("checkBoxPrefff")) { 
         sharedPreferences.getBoolean(key,true);
    }
 }

Does sharedPreferences use default database ( ..._preference.xml ) or my defined database ( "myPreferenceDB" )? Does key is "checkboxKey" or is null?

Because when I want to get value like

SharedPreferences temp = context.getSharedPreferences(
                                         "myPreferenceDB", Context.MODE_PRIVATE);
boolean flag = temp.getBoolean("checkboxKey",true);

it's wrong and gets back defValue (true) . But when use like

SharedPreferences temp = PreferenceManager.getDefaultSharedPreferences(context);
boolean flag = temp.getBoolean("checkboxKey",true);

it works.

回答1:

Once again I would like to mention sharedPref is not a DB but rather an XML file. I hope you are looking for the following code.

public class SettingsActivity extends PreferenceActivity {

    /*
     * (non-Javadoc)
     * 
     * @see android.preference.PreferenceActivity#onCreate(android.os.Bundle)
     */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getPreferenceManager().setSharedPreferencesName("myPref"); 
        addPreferencesFromResource(R.xml.pref);
    }

回答2:

You can register a SharedPreferenceChangedListener on any shared pref that you are using. It need not be the default shared preference.

getApplicationContext().getSharedPreferences("myPreferenceDB", 0).registerOnSharedPreferenceChangeListener(new OnSharedPreferenceChangeListener() {

        @Override
        public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
                String key) {
            // TODO Auto-generated method stub

        }
    });

来源：https://stackoverflow.com/questions/13286822/onsharedpreferencechanged-without-using-getdefaultsharedpreferences