通過利用Service來實現該功能 將要播放的歌曲放入raw文件夾中

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1. <strong>新建一個AudioService?類，<span?style="font-family:?Arial,?Helvetica,?sans-serif;">AudioService?類</span><span?style="font-family:?Arial,?Helvetica,?sans-serif;">繼承?android.app.Service，幾個有關Service?的重要概念如下：</span>??
2. ??
3. 1.?Service?對象以?separated?process?的方式執行，這表示?Service?與?UI（Activity）并不在同一個?process?里執行，而是各自在不同的?process?執行。??
4. ??
5. 2.?Android應用程序是在?Activity?啟動與停止?Service。??
6. ??
7. 3.?重載（override）onStart()?方法（method）在?Service?被啟動，執行我們想要的背景功能。??
8. ??
9. 4.?重載?onDestroy()?方法在?Service?被停止時，停止執行中的背景功能。</strong>??

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1. <pre?name="code"?class="html"><strong>2、AudioService類??
2. [java]?</strong>??
3. package?demo.camera;????
4. import?android.app.Service;????
5. import?android.content.Intent;????
6. import?android.media.MediaPlayer;????
7. import?android.os.Binder;????
8. import?android.os.IBinder;????
9. import?android.widget.MediaController.MediaPlayerControl;????
10. /**???
11. ?*?為了可以使得在后臺播放音樂，我們需要Service???
12. ?*?Service就是用來在后臺完成一些不需要和用戶交互的動作???
13. ?*?@author?Administrator???
14. ?*???
15. ?*/????
16. public?class?AudioService?extends?Service?implements?MediaPlayer.OnCompletionListener{????
17. ????????
18. ????MediaPlayer?player;????
19. ????????
20. ????private?final?IBinder?binder?=?new?AudioBinder();????
21. ????@Override????
22. ????public?IBinder?onBind(Intent?arg0)?{????
23. ????????//?TODO?Auto-generated?method?stub????
24. ????????return?binder;????
25. ????}????
26. ????/**???
27. ?????*?當Audio播放完的時候觸發該動作???
28. ?????*/????
29. ????@Override????
30. ????public?void?onCompletion(MediaPlayer?player)?{????
31. ????????//?TODO?Auto-generated?method?stub????
32. ????????stopSelf();//當結束時，便結束Service????
33. ????}????
34. ????????
35. ????//實例化MediaPlayer對象????
36. ????public?void?onCreate(){????
37. ????????super.onCreate();????
38. ????????//我們從raw文件夾中獲取一個應用自帶的mp3文件????
39. ????????player?=?MediaPlayer.create(this,?R.raw.eason);????
40. ????????player.setOnCompletionListener(this);????
41. ????}????
42. ????????
43. ????/**???
44. ?????*?該方法在SDK2.0才開始有的，用來替代原來的onStart方法???
45. ?????*/????
46. ????public?int?onStartCommand(Intent?intent,?int?flags,?int?startId){????
47. ????????if(!player.isPlaying()){????
48. ????????????player.start();????
49. ????????}????
50. ????????return?START_STICKY;????
51. ????}????
52. ????????
53. ????public?void?onDestroy(){????
54. ????????//super.onDestroy();????
55. ????????if(player.isPlaying()){????
56. ????????????player.stop();????
57. ????????}????
58. ????????player.release();????
59. ????}????
60. ????????
61. ????//為了和Activity交互，我們需要定義一個Binder對象????
62. ????class?AudioBinder?extends?Binder{????
63. ????????????
64. ????????//返回Service對象????
65. ????????AudioService?getService(){????
66. ????????????return?AudioService.this;????
67. ????????}????
68. ????}????
69. ????????
70. ????//后退播放進度????
71. ????public?void?haveFun(){????
72. ????????if(player.isPlaying()?&&?player.getCurrentPosition()>2500){????
73. ????????????player.seekTo(player.getCurrentPosition()-2500);????
74. ????????}????
75. ????}????
76. }????

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1. <pre?name="code"?class="html">至此，一個完整的服務生成，接下來是在Activity中啟動服務。??
2. <strong>修改?AndroidManifest.xml：??
3. ??
4. 在?Package?Explorer?視窗里找到目前?Android?項目的資訊描述檔，名稱為?AndroidManifest.xml。這是一個用來描述?Android?應用程序「整體資訊」的文件，每個?Android?應用程序項目都會有一個。在這里修改?Androidmanifest.xml?的目的是為了「?Android?應用程序加入一個?Service?類別」，這樣才有辦法驅動?Service。</strong>??
5. [html]???

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1. <?xml?version="1.0"?encoding="utf-8"?>????
2. <manifest?xmlns:android="http://schemas.android.com/apk/res/android"????
3. ????package="com.android"????
4. ????android:versionCode="1"????
5. ????android:versionName="1.0"?>????
6. ????
7. ????<uses-sdk?android:minSdkVersion="10"?/>????
8. ????
9. ????<application????
10. ????????android:icon="@drawable/ic_launcher"????
11. ????????android:label="@string/app_name"?>????
12. ????????<activity????
13. ????????????android:name=".WebTestActivity"????
14. ????????????android:label="@string/app_name"?>????
15. ????????????<intent-filter>????
16. ????????????????<action?android:name="android.intent.action.MAIN"?/>????
17. ????
18. ????????????????<category?android:name="android.intent.category.LAUNCHER"?/>????
19. ????????????</intent-filter>????
20. ????????</activity>????
21. ????????<service????
22. ????????????<pre?name="code"?class="html">????????????android:name=".AudioService"??

android:exported="true" android:process=":remote"> </service> </application> </manifest>

轉載于:https://www.cnblogs.com/whm1234/p/4650893.html

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