android中播放音乐

朱雀 2022-07-13 00:24 267阅读 0赞

1、最好是把代码写到服务中，退出app应用，播放的音乐也不会停止，为了测试方便，在activity中就直接写代码了，先把一个音乐文件放到sd卡中，需要用到的权限（api文档介绍说：1是网络请求、2是不让屏幕变暗）

*  **Internet Permission** - If you are using MediaPlayer to stream network-based content, your application must request network access.
    
        <uses-permission android:name="android.permission.INTERNET" />
 *  **Wake Lock Permission** - If your player application needs to keep the screen from dimming or the processor from sleeping, or uses the `MediaPlayer.setScreenOnWhilePlaying()` or `MediaPlayer.setWakeMode()`methods, you must request this permission.
    
        <uses-permission android:name="android.permission.WAKE_LOCK" />

2、布局文件代码：

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/activity_player_music"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:padding="16dp"
        android:orientation="vertical"
        tools:context="zhuyu.testrp.example.com.PlayerMusicActivity">
    
        <TextView
            android:text="输入本地或网络音乐地址:"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />
    
        <EditText
            android:hint="请输入播放地址"
            android:maxLines="1"
            android:text="/storage/emulated/0/msmm.mp3"
            android:id="@+id/et_player_music"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    
        <LinearLayout
            android:paddingTop="20dp"
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
    
            <Button
                android:id="@+id/player_music_play"
                android:text="播放"
                android:layout_weight="1"
                android:layout_width="0dp"
                android:layout_height="wrap_content" />
    
            <Button
                android:id="@+id/player_music_pause"
                android:text="暂停"
                android:layout_weight="1"
                android:layout_width="0dp"
                android:layout_height="wrap_content" />
    
            <Button
                android:id="@+id/player_music_replay"
                android:text="重播"
                android:layout_weight="1"
                android:layout_width="0dp"
                android:layout_height="wrap_content" />
    
            <Button
                android:id="@+id/player_music_stop"
                android:text="停止"
                android:layout_weight="1"
                android:layout_width="0dp"
                android:layout_height="wrap_content" />
        </LinearLayout>
    
        <TextView
            android:id="@+id/tv_player_music"
            android:paddingTop="20dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />
    </LinearLayout>

3、对应activity中的代码：

public class PlayerMusicActivity extends AppCompatActivity implements View.OnClickListener {
        private TextView tv_player_music;
        private EditText et_player_music;
        private Button player_music_play,player_music_pause,player_music_replay,player_music_stop;
        private MediaPlayer mediaPlayer;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_player_music);
    
            et_player_music = (EditText) findViewById(R.id.et_player_music);
            tv_player_music = (TextView) findViewById(R.id.tv_player_music);
            player_music_play = (Button) findViewById(R.id.player_music_play);
            player_music_pause = (Button) findViewById(R.id.player_music_pause);
            player_music_replay = (Button) findViewById(R.id.player_music_replay);
            player_music_stop = (Button) findViewById(R.id.player_music_stop);
    
            player_music_play.setOnClickListener(this);
            player_music_pause.setOnClickListener(this);
            player_music_replay.setOnClickListener(this);
            player_music_stop.setOnClickListener(this);
        }
    
    
        @Override
        public void onClick(View v) {
            switch (v.getId()){
                case R.id.player_music_play :
                    play();
                    break;
                case R.id.player_music_pause :
                    pause();
                    break;
                case R.id.player_music_replay :
                    replay();
                    break;
                case R.id.player_music_stop :
                    stop();
                    break;
            }
        }
    
        /**
         * 停止
         */
        private void stop() {
            if (mediaPlayer != null){
                mediaPlayer.stop();
                mediaPlayer.release();
                mediaPlayer = null;
                player_music_play.setEnabled(true);
            }
        }
    
        /**
         * 重播
         */
        private void replay() {
            if (mediaPlayer != null){
                mediaPlayer.seekTo(0);
                return;
            }
            play();
        }
    
        /**
         * 暂停
         */
        private void pause() {
            if ("继续".equals(player_music_pause.getText().toString().trim())){
                mediaPlayer.start();
                player_music_pause.setText("暂停");
                return;
            }
    
            if (mediaPlayer != null && mediaPlayer.isPlaying()){
                mediaPlayer.pause();
                player_music_pause.setText("继续");
                return;
            }
        }
    
        /**
         * 播放
         */
        private void play() {
            String player_music_path = et_player_music.getText().toString().trim();
            if (player_music_path.equals("")){
                Toast.makeText(this,"请输入正确地址",1).show();
                return;
            }
    
            try {
                mediaPlayer = new MediaPlayer();
                mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
                mediaPlayer.setDataSource(player_music_path);
                mediaPlayer.prepare();
                mediaPlayer.start();
                mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener(){
                    @Override
                    public void onCompletion(MediaPlayer mp) {
                        player_music_play.setEnabled(true);
                    }
                });
                mediaPlayer.setOnErrorListener(new MediaPlayer.OnErrorListener(){
                    @Override
                    public boolean onError(MediaPlayer mp, int what, int extra) {
                        player_music_play.setEnabled(true);
                        return false;
                    }
                });
    
                long mtime = mediaPlayer.getDuration();
                tv_player_music.setText("播放时长：" + timeParse(mtime));
                player_music_play.setEnabled(false);
            } catch (Exception e) {
                e.printStackTrace();
                Toast.makeText(this,"播放失败",1).show();
            }
        }
        //Android 音乐播放器应用里，读出的音乐时长为 long 类型以毫秒数为单位，例如：将 234736 转化为分钟和秒应为 03:55 （包含四舍五入）
        public static String timeParse(long duration) {
            String time = "" ;
            long minute = duration / 60000 ;
            long seconds = duration % 60000 ;
            long second = Math.round((float)seconds/1000) ;
            if( minute < 10 ){
                time += "0" ;
            }
            time += minute+":" ;
            if( second < 10 ){
                time += "0" ;
            }
            time += second ;
            return time ;
        }
    }