Android - How to change texts in the preferences activity dynamically?

Question

Hello fellow programmers, I have a little problem with Preferences activity.

http://developer.android.com/reference/android/preference/PreferenceActivity.html

I've got just one preference category and a listPreference:

<?xml version="1.0" encoding="utf-8"?>

<PreferenceCategory android:title="@string/basic_settings" >
    <ListPreference
        android:defaultValue="70"
        android:entries="@array/listArray"
        android:entryValues="@array/listValues"
        android:key="updates_interval"
        android:persistent="true"
        android:summary="@string/SOME_SUMMARY"
        android:title="@string/SOME_TITLE" />
</PreferenceCategory>

I need to have the selected value (the default one or the user defined one) written in the summary of the listPreference, for example: We will have at least 70 characters.

How can I do this from the code?

Any help is appreciated

Answer 1

Try like this..

 Preference customPref = (Preference) findPreference("updates_interval");<-- your preferences key
 customPref.setSummary("desired string");

Answer 2

here is a short example:

Preference etp = (Preference) findPreference("the_pref_key");
etp.setSummary("New summary");

This requires that you display your preferences either from a PreferenceActivity or from a PreferenceFragment, since findPreference() is a method of these classes. You most likely do that already.

To change the summary every time the user changes the actual preference, use a OnPreferenceChangeListener and check if the relevant key changed in the callback. After it has changed, just edit the summary like above.