onSharedPreferenceChanged没有更新首选项

Question

所以我想更改我的timers.java类中的值时，首选项已更改。这里是

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

我所说的是在OnCreate，如果我改变的一个，回去2个屏幕我们向Main.java然后重新启动timers.java的变化将工作在我timers.java值，但是如果我只是进入的喜好，然后回给timers.java更改不会生效

这里是我的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); 
     } 
    } 



} 

即时猜测我有onSharedPreferenceChanged是不正确的？不太确定我需要把If语句放到if语句中以获取布尔值的值更改为timers.java

任何帮助将不胜感激！

谢谢！

编辑：有人张贴解答哪种类型的解决了这一问题

我已经改变了我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)); 
     } 
    } 

现在，这更新的价值，但它是工作，每当我选中或取消选中盒子，它抛出一个错误

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

你为什么要手动调用onSharedPreferenceChanged并将其传递空和空字符串作为arguements？您的代码中删除onSharedPreferenceChanged(null, "");。