Android：SettingsActivity，确认密码？

Question

I have a settingsactivity and I have a edittext with a passwordfield. I only contains 4 numbers and numbers only.

How, when the user clicks this, can I make the user be forced to confirm the old password before entering a new one?

Activity:

addPreferencesFromResource( R.xml.pref_general );

res/xml/pref_general.xml

<PreferenceCategory android:title="@string/settings_general">
    <EditTextPreference
            android:title="@string/settings_password"
            android:key="example_password"
            android:summary="****"
            android:textColor="@color/textColor"
            android:textColorHint="@color/hintColor"
            android:inputType="number"
            android:maxLength="4"
            />

</PreferenceCategory>

How can I find the items so that I can put my own onClickListener's on them?

Edit: I found this method, currently trying to figure this out..

private static Preference.OnPreferenceClickListener onPreferenceClickListener = new Preference.OnPreferenceClickListener() {

    @Override
    public boolean onPreferenceClick( Preference preference ) {
        return false;
    }

};

Answer 1

You can register a listener within your PreferenceActivity:

@Override
public void onResume() {
    super.onResume();
    getPreferenceManager().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
}

@Override
public void onPause() {    
    getPreferenceManager().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
    super.onPause();
}

@Override
public void onSharedPreferenceChanged( SharedPreferences sharedPreferences, String key) {
    Log.i("onSharedPreferenceChanged", "preference changed: " + key);
}

Answer 2

I noticed this from another question from searching a bit more.

    Preference myPref = ( Preference ) findPreference( "password" );
    myPref.setOnPreferenceClickListener( new Preference.OnPreferenceClickListener() {
        public boolean onPreferenceClick( Preference preference ) {
            Log.e("App", "password clicked!");
            return true;
        }
    } );

Works!

Edit: This would probably have to be in the onPostCreate() method because it needs to be initialized before you can set any sort of listeners to it (or even find the object).