android 第三次作业

时间:2024-01-13 14:23:08

android studio音乐播放器

一、实现功能:

1.读取本地SD中的所有音频文件

2.歌单列表展示,并显示音频具体信息

3.进度条显示当前播放进度,可滑动加速

4.点击歌单进行播放

5.实现暂停、播放、下一曲、上一曲

二、页面截图:

android 第三次作业。。。。。。。。。。。。。。。。。。android 第三次作业

三、关键代码实现

1.首先获取从SD卡中读取本地文件的权限:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

2.Android系统会在SD卡有更新的时候自动将SD卡文件分类并存入SQLite数据库,而我们要做的只是像正常读取数据库一样去读数据库的信息

新建MusicMedia类进行详细信息的保存:

package com.example.pc.music;

public class MusicMedia {
private int id;
private String title;
private String artist;
private String url;
private String time;
private String size;
private int albumId;
private String album;

在主类中获取详细信息

  /*加载媒体库里的音频*/
public ArrayList<MusicMedia> scanAllAudioFiles(){
//生成动态数组,并且转载数据
ArrayList<MusicMedia> mylist = new ArrayList<MusicMedia>();
Cursor cursor = getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null, null, MediaStore.Audio.Media.DEFAULT_SORT_ORDER);
//遍历媒体数据库
if(cursor.moveToFirst()){
while (!cursor.isAfterLast()) {
    //歌曲标题
String tilte = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.TITLE));
//歌曲的歌手名: MediaStore.Audio.Media.ARTIST
String artist = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST));
//歌曲的总播放时长 :MediaStore.Audio.Media.DURATION
int duration = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DURATION));
//歌曲文件的大小 :MediaStore.Audio.Media.SIZE
Long size = cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE));
if (size >1024*800){//大于800K
MusicMedia musicMedia = new MusicMedia();
musicMedia.setId(id);
musicMedia.setArtist(artist);
musicMedia.setSize(size);
musicMedia.setTitle(tilte);
musicMedia.setTime(duration);
musicMedia.setUrl(url);
musicMedia.setAlbum(album);
musicMedia.setAlbumId(albumId); mylist.add(musicMedia); }
cursor.moveToNext();
}
}
return mylist;
}

3.使用MediaPlayer进行点击播放:使用mediaplayer传一个地址过去,这些信息在刚读取音频的方法里都有,传一个地址过去使用一个service先播放起来

musicListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//点击播放音乐,不过需要判断一下当前是否有音乐在播放,需要关闭正在播放的 currentposition = position;
player(currentposition);
}
});

新建service

<service
android:name=".MusicPlayerService"
android:enabled="true"
android:exported="true">
<intent-filter >
<action android:name="player"></action>
</intent-filter>
</service>

4.进度条显示当前进度:service使用静态的变量,activity里也是使用静态的变量,然后开一个线程,1s更新一次状态,在service里直接修改seekbar

public class MusicPlayerService extends Service implements Runnable {
private static final String TAG = "MusicPlayerService";
private static final int NOTIFICATION_ID = 1; // 如果id设置为0,会导致不能设置为前台service
public static MediaPlayer mediaPlayer = null;
private String url = null;
private String MSG = null;
private static int curposition;//第几首音乐
private musicBinder musicbinder = null;
private int currentPosition = 0;// 设置默认进度条当前位置
public MusicPlayerService() {
Log.i(TAG,"MusicPlayerService......1");
musicbinder = new musicBinder();
}
//通过bind 返回一个IBinder对象,然后改对象调用里面的方法实现参数的传递
@Override
public IBinder onBind(Intent intent) {
Log.i(TAG,"onBind......");
return null;
} @Override
public void onCreate() {
Log.i(TAG, "onCreate......2");
super.onCreate();
if (mediaPlayer == null) {
/* mediaPlayer.reset();
mediaPlayer.release();
mediaPlayer = null;*/
mediaPlayer = new MediaPlayer();
}
// 监听播放是否完成
mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) { }
}); } @Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i(TAG, "onStartCommand......3");
// /storage/emulated/0/Music/Download/Selena Gomez - Revival/Hands to Myself.mp3
if(intent != null){
MSG = intent.getStringExtra("MSG");
if(MSG.equals("0")){
url = intent.getStringExtra("url");
Log.i(TAG, url + "......." + Thread.currentThread().getName());
palyer();
}else if(MSG.equals("1")){
mediaPlayer.pause();
}else if(MSG.equals("2")){
mediaPlayer.start();
} } return super.onStartCommand(intent, flags, startId);
} private void palyer() {
Log.i(TAG,"palyer......"); //用户在暂停是点击其他的音乐,所以不管当前状态,都重置一下
//下面这段代码可以实现简单的音乐播放
try {
// Log.i(TAG,"palyer......new....");
mediaPlayer.reset(); mediaPlayer.setDataSource(url);
mediaPlayer.setLooping(true);
// mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.prepare();
mediaPlayer.start();
// 设置进度条最大值
MusicActivity.audioSeekBar.setMax(mediaPlayer.getDuration());
//开启新线程
new Thread(this).start();
} catch (IOException e) {
e.printStackTrace();
}
}
// 刷新进度条 ,时间 @Override
public void run() { Log.i(TAG,Thread.currentThread().getName()+"......run..."); int total = mediaPlayer.getDuration();// 总时长
while (mediaPlayer != null && currentPosition < total) {
try {
Thread.sleep(1000);
if (mediaPlayer != null) {
currentPosition = mediaPlayer.getCurrentPosition();
}
} catch (InterruptedException e) {
e.printStackTrace();
}
MusicActivity.audioSeekBar.setProgress(CurrentPosition);
}
}
@Override
public void onDestroy() {
Log.i(TAG,"onDestroy......");
super.onDestroy();
if (mediaPlayer != null) {
mediaPlayer.stop();
mediaPlayer.release();
mediaPlayer = null;
}
//关闭线程
Thread.currentThread().interrupt();
stopForeground(true);
}
public String toTime(int time){
time /= 1000;
int minute = time / 60;
int hour = minute / 60;
int second = time % 60;
minute %= 60;
return String.format("%02d:%02d", minute, second);
}
}

还有一些播放按钮点击更改样式、判断在第一首或最后一首时点击上一首或下一首的提示等功能

四、coding链接:

https://coding.net/u/dsy1600802076/p/android3/git

五:APK下载:

apk下载

 六:录屏链接:

手机录屏已上传至优酷

由于未知原因,上传后声音不同步,有点遗憾。