HOW TO：ListPreference上的侦听器以更改Google Map模式？

Question

I want to make the ListPreference with key "map_mode" set the actual map mode in my MapActivity.java . So that when I click "Satellite" for instance in the Preferences screen, it changes on the Map.

I have a ListPreference setup like this settings.xml (preference.xml):

    <PreferenceCategory
        android:key="settings"
        android:title="Settings" >
    <CheckBoxPreference
        android:defaultValue="true"
        android:key="map_settings"
        android:summary="Enable or Disable Map Settings"
        android:title="Enable Map Settings" />

    <ListPreference
        android:defaultValue="Map"
        android:dependency="map_settings"
        android:entries="@array/mapMode"
        android:entryValues="@array/mapModeValues"
        android:key="map_mode"
        android:summary="Change the display of the map"
        android:title="Map Mode" />
</PreferenceCategory>

The "map_mode" is reading array values from this arrays.xml :

<string-array name="mapMode">
    <item name="Map">Map</item>
    <item name="Satellite">Satellite</item>
    <item name="Traffic">Traffic</item>
</string-array>

<string-array name="mapModeValues">
    <item name="Map">Map</item>
    <item name="Satellite">Satellite</item>
    <item name="Traffic">Traffic</item>
</string-array>

Thank you.

This is PreferenceScreen. When user presses one of these options I want it to update the MapActivity.

Answer 1

Have your MapActivity call registerOnSharedPreferenceChangeListener() , then process the SharedPreference change in your OnSharedPreferenceChangeListener .

Or, simply re-read and apply the preference in onResume() , since your PreferenceActivity and your MapActivity will not be on the screen at the same time.