1 原生Music 暫停的時候，會刪除通知欄上的通知。

2 原生Music 通知欄不能控制音樂，比如下一首，上一首，暫停/播放。

一 解決思路：

1 接到暫停廣播時，只暫停，不去除通知。

/packages/apps/Music/src/com/android/music/MediaPlaybackService.java中

呼叫的 stopForeground(true)方法控制去除通知

2 自定義音樂通知，新增按鈕事件。

   /packages/apps/Music/src/com/android/music/MediaPlaybackService.java中

  updateNotification()方法中自定義Notification,關鍵對RemoteViews 的理解

二  修改後效果圖：

三 詳細程式碼

1 接到暫停廣播時，只暫停，不去除通知

原始碼 採取的策略是 只要暫停就去除通知，這就會造成一個問題就是，當播放視訊的時候音樂播放器接受到暫停的廣播，於是消除了通知欄。

1.1 新增暫停 不消除通知的方法 pause(boolean isStopForeground)

1. privatevoid pause(boolean isStopForeground) {  
2.         synchronized(this) {  
3.             mMediaplayerHandler.removeMessages(FADEUP);  
4.             if (isPlaying()) {  
5.                 mPlayer.pause();  
6.                 gotoIdleState(isStopForeground);  
7.                 mIsSupposedToBePlaying = false;  
8.                 notifyChange(PLAYSTATE_CHANGED);  
9.                 saveBookmarkIfNeeded();  
10.             }  
11.         }  
12.     }  
13.     private
    void gotoIdleState(boolean isStopForeground) {  
14.         mDelayedStopHandler.removeCallbacksAndMessages(null);  
15.         Message msg = mDelayedStopHandler.obtainMessage();  
16.         mDelayedStopHandler.sendMessageDelayed(msg, IDLE_DELAY);  
17.        //此方法控制消除通知
18.         stopForeground(isStopForeground);  
19.     }  

1. private BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {  
2.         @Override
3.         publicvoid onReceive(Context context, Intent intent) {  
4.             String action = intent.getAction();  
5.             String cmd = intent.getStringExtra("command");  
6.             MusicUtils.debugLog("mIntentReceiver.onReceive " + action + " / " + cmd);  
7.             if (CMDNEXT.equals(cmd) || NEXT_ACTION.equals(action)) {  
8.                 gotoNext(true);  
9.             } elseif (CMDPREVIOUS.equals(cmd) || PREVIOUS_ACTION.equals(action)) {  
10.                 prev();  
11.             } elseif (CMDTOGGLEPAUSE.equals(cmd) || TOGGLEPAUSE_ACTION.equals(action)) {  
12.                 if (isPlaying()) {  
13.                     /*Begin: modified  */
14.                     pause(false);  
15.                     updateNotification();  
16.                     /*End: */
17.                     mPausedByTransientLossOfFocus = false;  
18.                 } else {  
19.                     play();  
20.                 }  
21.             } elseif (CMDPAUSE.equals(cmd) || PAUSE_ACTION.equals(action)) {  
22.                 /*Begin: modified  */
23.                 pause(false);  
24.                 updateNotification();  
25.                 /*End:*/
26.                 mPausedByTransientLossOfFocus = false;  
27.             } elseif (CMDPLAY.equals(cmd)) {  
28.                               ...  

2.1 通知的佈局檔案 /packages/apps/Music/res/layout/statusbar.xml

1. <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
2.     android:layout_width="match_parent"
3.     android:layout_height="wrap_content"
4.     android:orientation="horizontal">
5.     <LinearLayout
6.         xmlns:android="http://schemas.android.com/apk/res/android"
7.         android:layout_width="wrap_content"
8.         android:layout_height="wrap_content"
9.         android:orientation="horizontal"
10.         android:layout_gravity="center_vertical">
11.         <!-- 圖示 -->
12.         <ImageView
13.             android:id="@+id/icon"
14.             android:layout_width="wrap_content"
15.             android:layout_height="wrap_content"
16.             android:gravity="center"
17.             android:padding="4dip">
18.         </ImageView>
19.     </LinearLayout>
20.     <LinearLayout
21.         android:layout_width="match_parent"
22.         android:layout_height="wrap_content"
23.         android:orientation="vertical">
24.         <LinearLayout
25.             android:layout_width="match_parent"
26.             android:layout_height="wrap_content"
27.             android:orientation="horizontal">
28.               <!-- 音樂名 -->
29.             <TextView
30.                 android:id="@+id/trackname"
31.                 style="@android:style/TextAppearance.StatusBar.EventContent.Title"
32.                 android:layout_width="80dip"
33.                 android:layout_height="wrap_content"
34.                 android:layout_gravity="left"
35.                 android:ellipsize="marquee"
36.                 android:focusable="true"
37.                 android:singleLine="true"/>
38.             <RelativeLayout
39.                 android:layout_width="match_parent"
40.                 android:layout_height="match_parent">
41.                   <!-- 上一首 -->
42.                 <ImageButton
43.                     android:id="@+id/statusbar_prev"
44.                     style="@android:style/MediaButton.Previous"
45.                     android:layout_width="wrap_content"
46.                     android:layout_height="wrap_content"
47.                     android:layout_alignParentLeft="true"/>
48.                   <!-- 暫停/播放 -->
49.                 <ImageButton
50.                     android:id="@+id/statusbar_pause"
51.                     style="@android:style/MediaButton.Pause"
52.                     android:layout_width="wrap_content"
53.                     android:layout_height="wrap_content"
54.                     android:layout_centerHorizontal="true"/>
55.                   <!-- 下一首 -->
56.                 <ImageButton
57.                     android:id="@+id/statusbar_next"
58.                     style="@android:style/MediaButton.Next"
59.                     android:layout_width="wrap_content"
60.                     android:layout_height="wrap_content"
61.                     android:layout_alignParentRight="true"
62.                     android:gravity="right"/>
63.             </RelativeLayout>
64.         </LinearLayout>
65.          <!-- 專輯資訊，歌手 -->
66.         <TextView
67.             android:id="@+id/artistalbum"
68.             style="@android:style/TextAppearance.StatusBar.EventContent"
69.             android:layout_width="wrap_content"
70.             android:layout_height="wrap_content"
71.             android:layout_gravity="left"
72.             android:ellipsize="end"
73.             android:maxLines="2"
74.             android:scrollHorizontally="true"/>
75.     </LinearLayout>
76. </LinearLayout>

2.2  通知欄控制：

/packages/apps/Music/src/com/android/music/MediaPlaybackService.java中

 updateNotification（）為傳送的通知程式碼，在這裡面修改

1. privatevoid updateNotification() {  
2.         //RemoteViews未自定義佈局，   R.layout.statusbar 為通知的佈局檔案
3.         RemoteViews views = new RemoteViews(getPackageName(), R.layout.statusbar);  
4.         views.setImageViewResource(R.id.icon, R.drawable.stat_notify_musicplayer);  
5.         if (getAudioId() < 0) {  
6.             // streaming
7.             views.setTextViewText(R.id.trackname, getPath());  
8.             views.setTextViewText(R.id.artistalbum, null);  
9.         } else {  
10.             String artist = getArtistName();  
11.             views.setTextViewText(R.id.trackname, getTrackName());  
12.             if (artist == null || artist.equals(MediaStore.UNKNOWN_STRING)) {  
13.                 artist = getString(R.string.unknown_artist_name);  
14.             }  
15.             String album = getAlbumName();  
16.             if (album == null || album.equals(MediaStore.UNKNOWN_STRING)) {  
17.                 album = getString(R.string.unknown_album_name);  
18.             }  
19.             views.setTextViewText(R.id.artistalbum,  
20.                     getString(R.string.notification_artist_album, artist, album)  
21.                     );  
22.         }  
23.         Notification status = new Notification();  
24.         /*Begin: modified 新增修改程式碼*/
25.         //status_icon 為狀態列圖示,R.id.statusbar_pause 為通知 的 暫停/開始按鈕
26.         int status_icon = R.drawable.ic_appwidget_music_play;  
27.         //根據播放狀態，來決定 暫停/開始 圖示
28.         if(isPlaying()){  
29.             views.setImageViewResource(R.id.statusbar_pause, R.drawable.ic_appwidget_music_pause);   
30.         }else{  
31.             views.setImageViewResource(R.id.statusbar_pause, R.drawable.ic_appwidget_music_play);  
32.             status_icon = R.drawable.ic_appwidget_music_pause;  
33.          }  
34.          // 給通知欄 上一首 按鈕 新增點選事件  
35.         views.setOnClickPendingIntent(R.id.statusbar_prev, pre_PendingIntent());  
36.         //給通知欄 暫停/開始 按鈕 新增點選事件 
37.         views.setOnClickPendingIntent(R.id.statusbar_pause, pause_PendingIntent());  
38.         //給通知欄 下一首 按鈕 新增點選事件
39.         views.setOnClickPendingIntent(R.id.statusbar_next, next_PendingIntent());  
40.         /*End:  */
41.         status.contentView = views;  
42.         status.flags |= Notification.FLAG_ONGOING_EVENT;  
43.         status.icon = status_icon;  
44.         status.contentIntent = PendingIntent.getActivity(this, 0,  
45.                 new Intent("com.android.music.PLAYBACK_VIEWER")  
46.                 .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK), 0);  
47.         startForeground(PLAYBACKSERVICE_STATUS, status);  
48.     }  

新增的點選事件函式：

1. /*Begin:  modify  利用MediaPlaybackService 現有的廣播監聽 實現播放控制 */
2.     //上一首，
3.     private PendingIntent pre_PendingIntent(){  
4.         Intent intent = new Intent(PREVIOUS_ACTION);  
5.         PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);  
6.          return pendingIntent;  
7.     }  
8.     //暫停開始 
9.     private PendingIntent pause_PendingIntent(){  
10.         Intent intent = new Intent(TOGGLEPAUSE_ACTION);  
11.         PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);  
12.          return pendingIntent;  
13.     }  
14.     //下一首 
15.     private PendingIntent next_PendingIntent(){  
16.         Intent intent = new Intent(NEXT_ACTION);  
17.         PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);  
18.          return pendingIntent;  
19.     }  
20.     /*end:  */

其一 play()  方法中 將  updateNotification() 放在了

if (!mIsSupposedToBePlaying) {
                mIsSupposedToBePlaying = true;
                notifyChange(PLAYSTATE_CHANGED);
            }

之後

1. publicvoid play() {  
2.             ...  
3. if (!mIsSupposedToBePlaying) {  
4.                 mIsSupposedToBePlaying = true;  
5.                 notifyChange(PLAYSTATE_CHANGED);  
6.             }  
7. updateNotification();  
8.           ...  
9. }  

1. private BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {  
2.        @Override
3.        publicvoid onReceive(Context context, Intent intent) {  
4.            String action = intent.getAction();  
5.            String cmd = intent.getStringExtra("command");  
6.            MusicUtils.debugLog("mIntentReceiver.onReceive " + action + " / " + cmd);  
7.            Log.e(LOGTAG, "  mIntentReceiver   action = "+action+"   cmd ="+cmd+"===");  
8.            if (CMDNEXT.equals(cmd) || NEXT_ACTION.equals(action)) {  
9.                gotoNext(true);  
10.            } elseif (CMDPREVIOUS.equals(cmd) || PREVIOUS_ACTION.equals(action)) {  
11.                prev();  
12.            } elseif (CMDTOGGLEPAUSE.equals(cmd) || TOGGLEPAUSE_ACTION.equals(action)) {  
13.                if (isPlaying()) {  
14.                    /*Begin: 開始修改*/
15.                   // pause(false); 暫停時不消除通知欄
16.                    pause(false);  
17.                    updateNotification();  
18.                    /*End: modified*/
19.                    mPausedByTransientLossOfFocus = false;  
20.                } else {  
21.                    play();  
22.                }  
23.                                ...