onSharedPreferenceChanged沒有更新首選項

Question

所以我想更改我的timers.java類中的值時，首選項已更改。這裏是

final boolean soundEnabledPref = sharedPref.getBoolean(spawnTimers.KEY_PREF_SOUND, false); 

我所說的是在OnCreate，如果我改變的一個，回去2個屏幕我們向Main.java然後重新啓動timers.java的變化將工作在我timers.java值，但是如果我只是進入的喜好，然後回給timers.java更改不會生效

這裏是我的settingsFragment.java

import android.content.SharedPreferences; 
import android.content.SharedPreferences.OnSharedPreferenceChangeListener; 
import android.os.Bundle; 
import android.preference.PreferenceFragment; 

public class settingsFragment extends PreferenceFragment implements OnSharedPreferenceChangeListener { 

    public static final String KEY_PREF_SOUND_SETTINGS = "pref_key_sounds_settings"; 

    @Override 
    public void onCreate(Bundle savedInstanceState){ 
     super.onCreate(savedInstanceState); 

     addPreferencesFromResource(R.xml.preferences); 

     onSharedPreferenceChanged(null, ""); 
    } 

    @Override 
    public void onResume() { 
     super.onResume(); 
     // Set up a listener whenever a key changes 
     getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this); 
    } 

    @Override 
    public void onPause() { 
     super.onPause(); 
     // Unregister the listener whenever a key changes 
     getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this); 
    } 

    @Override 
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) 
    { 

     if (key.equals(KEY_PREF_SOUND_SETTINGS)) 
     { 
      boolean soundEnabledPref = sharedPreferences.getBoolean(spawnTimers.KEY_PREF_SPAWNSOUND, false); 
     } 
    } 



} 

即時猜測我有onSharedPreferenceChanged是不正確的？不太確定我需要把If語句放到if語句中以獲取布爾值的值更改爲timers.java

任何幫助將不勝感激！

謝謝！

編輯：有人張貼解答哪種類型的解決了這一問題

我已經改變了我onSharedPreferencesChanged到

@Override 
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) 
    { 

     if (key.equals(KEY_PREF_SPAWN_SOUNDS)) 
     { 
      CheckBoxPreference soundEnabledPref = (CheckBoxPreference)findPreference(KEY_PREF_SOUND_SETTINGS); 
      soundEnabledPref.setChecked(sharedPreferences.getBoolean(spawnTimers.KEY_PREF_SPAWNSOUND, false)); 
     } 
    } 

現在，這更新的價值，但它是工作，每當我選中或取消選中盒子，它拋出一個錯誤

01-24 13:35:36.558: E/AndroidRuntime(3681): FATAL EXCEPTION: main 
01-24 13:35:36.558: E/AndroidRuntime(3681): Process: com.rcd.helper, PID: 3681 
01-24 13:35:36.558: E/AndroidRuntime(3681): java.lang.ClassCastException: android.preference.PreferenceCategory cannot be cast to android.preference.CheckBoxPreference 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at com.rcd.helper.settingsFragment.onSharedPreferenceChanged(settingsFragment.java:43) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.app.SharedPreferencesImpl$EditorImpl.notifyListeners(SharedPreferencesImpl.java:475) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.app.SharedPreferencesImpl$EditorImpl.apply(SharedPreferencesImpl.java:385) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.preference.Preference.tryCommit(Preference.java:1372) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.preference.Preference.persistBoolean(Preference.java:1638) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.preference.TwoStatePreference.setChecked(TwoStatePreference.java:84) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.preference.TwoStatePreference.onClick(TwoStatePreference.java:70) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.preference.Preference.performClick(Preference.java:952) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.preference.PreferenceScreen.onItemClick(PreferenceScreen.java:215) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.widget.AdapterView.performItemClick(AdapterView.java:299) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.widget.AbsListView.performItemClick(AbsListView.java:1113) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.widget.AbsListView$PerformClick.run(AbsListView.java:2904) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.widget.AbsListView$3.run(AbsListView.java:3638) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.os.Handler.handleCallback(Handler.java:733) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.os.Handler.dispatchMessage(Handler.java:95) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.os.Looper.loop(Looper.java:137) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at android.app.ActivityThread.main(ActivityThread.java:5083) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at java.lang.reflect.Method.invokeNative(Native Method) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at java.lang.reflect.Method.invoke(Method.java:515) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593) 
01-24 13:35:36.558: E/AndroidRuntime(3681):  at dalvik.system.NativeStart.main(Native Method) 

Answer 1

你爲什麼要手動調用onSharedPreferenceChanged並將其傳遞空和空字符串作爲arguements？您的代碼中刪除onSharedPreferenceChanged(null, "");。