What is the problem?
Resolve the preference and set a listener that does the toast? Something like this for example
ListPreference listPreference = findPreference(key);
listPreference.setOnPreferenceChangeListener(new OnPreferenceChangeListener() {
@Override
public boolean onPreferenceChange(Preference preference, Object newValue) {
Toast.makeText(SettingsActivity.this, "second", Toast.LENGTH_LONG).show();
return true;
}
});