Android 7.0 在設定中新增加了充電提示音的開啟選項，但開啟後，插上充電線也是聽不到充電音。根據檢視程式碼可知，其實該充電提示音是指無線充電提示音。

  PowerManagerService.java中updateIsPoweredLocked函式中，

if (dockedOnWirelessCharger) {
 mNotifier.onWirelessChargingStarted();
 }

下面我們新增正常充電方式的提醒音量。

 frameworks/base/services/core/java/com/android/server/notification/NotificationManagerService.java

///導包@{ 
import android.media.RingtoneManager;
import android.media.Ringtone;
///}@

在private final BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) 中新增如下方法
      

else if (action.equals(Intent.ACTION_USER_UNLOCKED)) {
                final int user = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, USER_NULL);
                mConditionProviders.onUserUnlocked(user);
                mListeners.onUserUnlocked(user);
                mAssistants.onUserUnlocked(user);
                mZenModeHelper.onUserUnlocked(user);

            /// for charge 
 
[email protected]{ 
            }else if (action.equals(Intent.ACTION_POWER_CONNECTED)){
            final boolean enabled = Settings.Global.getInt(getContext().getContentResolver(),  
                            Settings.Global.CHARGING_SOUNDS_ENABLED, 1) != 0;  
            final String soundPath = Settings.Global.getString(getContext().getContentResolver(),  
                            Settings.Global.WIRELESS_CHARGING_STARTED_SOUND); 

             if (enabled && soundPath != null) {  
                 final Uri soundUri = Uri.parse("file://" + soundPath);  
                 if (soundUri != null) {  
                     final Ringtone sfx = RingtoneManager.getRingtone(getContext(), soundUri);  
                     if (sfx != null) {  
                         sfx.setStreamType(AudioManager.STREAM_SYSTEM);  
                          sfx.play();  
                      }  
                  }  
             }               
        }
        ///}@   


       public void onStart() {  //在方法中新增如下方法

        filter.addAction(Intent.ACTION_USER_STOPPED);
        filter.addAction(Intent.ACTION_USER_SWITCHED);
        /// for charge 
 
[email protected]{ 
        filter.addAction(Intent.ACTION_POWER_CONNECTED);
        ///}@
        filter.addAction(Intent.ACTION_USER_ADDED);
        filter.addAction(Intent.ACTION_USER_REMOVED);