2013-01-08 55 views
2

更新ListPreference這裏是我的preferences.xml安卓:用OnPreferenceChangeListener

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

<ListPreference 
    android:key="KEY_1" 
    android:title="Title" 
    android:summary="Summary" 
    android:dialogTitle="Dialog" 
    /> 
<ListPreference 
    android:key="KEY_2" 
    /> 
<ListPreference 
    android:key="KEY_3" 
    /> 
<ListPreference 
    android:key="KEY_4" 
    /> 

這裏是Settings.java:

public class Settings extends PreferenceActivity { 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    addPreferencesFromResource(R.xml.preferences); 

// some methods to generate entries and values for ListPreference 
final List List_1 = // something 
final List List_2 = // something 
final List List_3 = // something 

String[] entry_1 = List_1.toArray(new String[List_1.size()]); 
String[] entry_2 = List_2.toArray(new String[List_2.size()]); 
String[] entry_3 = List_3.toArray(new String[List_3.size()]); 

String[] value_1 = List_1.toArray(new String[List_1.size()]); 
String[] value_2 = List_2.toArray(new String[List_2.size()]); 
String[] value_3 = List_3.toArray(new String[List_3.size()]); 


    // set arrays for entries and values  
final ListPreference lp1 = (ListPreference)findPreference("KEY_1"); 
lp1.setEntries(entry_1); 
lp1.setEntryValues(value_2); 

ListPreference lp2 = (ListPreference)findPreference("KEY_2"); 
lp2.setEntries(entry_2); 
lp2.setEntryValues(value_1); 

ListPreference lp3 = (ListPreference)findPreference("KEY_3"); 
lp3.setEntries(entry_2); 
lp3.setEntryValues(value_2); 

ListPreference lp4 = (ListPreference)findPreference("KEY_4"); 
lp4.setEntries(entry_2); 
lp4.setEntryValues(value_3); 

// update lp2, lp3, lp4 

     lp1.setOnPreferenceChangeListener(new OnPreferenceChangeListener() { 
      @Override 
      public boolean onPreferenceChange(Preference preference, Object newValue) { 
       String listValue = (String) newValue; 

       ListPreference lp2 = (ListPreference)findPreference("KEY_2"); 
       lp2.setDefaultValue(listValue); 

       ListPreference lp3 = (ListPreference)findPreference("KEY_3"); 
       lp3.setDefaultValue(listValue); 

       ListPreference lp4 = (ListPreference)findPreference("KEY_4"); 
       lp4.setDefaultValue(listValue); 

       return true; 
      } 
     }); 
    } 
} 

這種運作良好對我來說只有一次即我在這裏錯過了什麼,以後再對lp2,lp3和lp4進行更新?我猜setDefaultValue只是創建一次性輸入共享首選項?

+0

你解決了你的問題嗎? –

回答

0

我懷疑你的匿名監聽器被垃圾收集 - 添加一些調試輸出,看是否監聽器被調用

lp1.setOnPreferenceChangeListener(new OnPreferenceChangeListener() { 
    @Override 
    public boolean onPreferenceChange(Preference preference, Object newValue) { 
     Log.d("Listener", "I listen"); 
     String listValue = (String) newValue; 
     // rest is the same 
    } 
}); 

如果您沒有看到調試打印你的聽衆移動到一個類字段和:

public class Settings extends PreferenceActivity { 

    private OnPreferenceChangeListener mListener=new OnPreferenceChangeListener(){ 
     @Override 
     public boolean onPreferenceChange(Preference preference, Object newValue){ 
      // as before 
     } 
    }; 
    // etc - I guess the line below is in onCreate() - correct your formatting ! 
    lp1.setOnPreferenceChangeListener(mListener); 
    } 
}