论自作音乐播放器涉及知识点总结

来源：互联网发布：seo是什么职位编辑：程序博客网时间：2024/06/06 19:52

1.内容提供者查找手机SD卡下的音乐

配置读取SD卡权限

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

//调用方法
List<Good>  list = GetMusic.Music(MainActivity.this);

package com.bawei.day07_music;import java.util.ArrayList;import com.bawei.vo.Good;import android.content.ContentResolver;import android.content.Context;import android.database.Cursor;import android.net.Uri;import android.provider.MediaStore;import android.provider.MediaStore.Audio;public class GetMusic {    public static ArrayList<Good> Music(Context context) {        ContentResolver resolver = context.getContentResolver();        // 内容提供者访问MediaStore.Audio.Media.EXTERNAL_CONTENT_URI        Cursor cursor = resolver.query(                MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null, null,                null);        ArrayList<Good> list=new ArrayList<Good>();        while (cursor.moveToNext()) {            // 名字            String name = cursor.getString(cursor                    .getColumnIndex(Audio.Media.TITLE));            // 专辑名            String album = cursor.getString(cursor                    .getColumnIndexOrThrow(Audio.Media.ALBUM));            // 歌手名            String artist = cursor.getString(cursor                    .getColumnIndexOrThrow(Audio.Media.ARTIST));            // URI歌曲文件存放路径            String path = cursor.getString(cursor                    .getColumnIndexOrThrow(Audio.Media.DATA));            // 歌曲文件播放时间长度            int duration = cursor.getInt(cursor                    .getColumnIndexOrThrow(Audio.Media.DURATION));            // 音乐文件大小            int size = cursor.getInt(cursor                    .getColumnIndexOrThrow(Audio.Media.SIZE));            //保存到集合            list.add(new Good(name,artist,path,false));        }        return list;    }}

2.播放音乐

//播放音乐    private void startMusic(int arg0) {        //让上一首停下        if (player != null && player.isPlaying()) {            player.stop();            player.reset();            player = null;                    }               try {            //播放器            player = new MediaPlayer();            //播放路径            player.setDataSource(list.get(arg0).getMusic());            //准备            player.prepare();            //播放            player.start();            //得到歌曲总进度            c = player.getDuration();            //给进度条seekbar设置最大值            seekBar.setMax(c);            //timer            time();        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }

//timer    private void time() {        // TODO Auto-generated method stub        //timer        timer = new Timer();        //播放进度100毫秒前进一下        timer.schedule(new TimerTask() {            private int d;            @Override            public void run() {                // TODO Auto-generated method stub                //得到当前播放进度                 d = player.getCurrentPosition();                //赋给seekbar                seekBar.setProgress(d);
                //handler传值 显示时间                Message message = Message.obtain();                message.arg1 = c;                message.arg2 = d;                handler.sendMessage(message);            }        }, 0, 100);    }

    //显示时间    Handler handler = new Handler() {        public void handleMessage(Message msg) {            //当前进度            int cu1 = msg.arg1;            //总长度            int cu2 = msg.arg2;            //转换成时间格式            SimpleDateFormat sim = new SimpleDateFormat("mm:ss");            String cur1 = sim.format(cu1);            String cur2 = sim.format(cu2);            //赋给textview            text1.setText(cur2);            text2.setText(cur1);                   };    };

3.暂停继续播放

                  if (player != null) {                        //音乐暂停                        player.pause();                        //得到当前seekBar进度                        m = seekBar.getProgress();                    }

                       //继续播放                        player.seekTo(m);

4.seekbar调整音乐播放进度

    //seekbar调整音乐播放进度                        seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {                            public void onStopTrackingTouch(SeekBar seekBar) {                                // TODO Auto-generated method stub                                if (player != null) {                                     //得到当前拖拽的进度                                    player.seekTo(seekBar.getProgress());
                                     //timer                                    timecan();
                                    //timer计时                                    time();                                }                            }                            public void onStartTrackingTouch(SeekBar seekBar) {                                // TODO Auto-generated method stub                                //清空timer                                timecan();                            }                            public void onProgressChanged(SeekBar seekBar,                                    int progress, boolean fromUser) {                                // TODO Auto-generated method stub                            }                        });

 ////清空timer    private void timecan() {        // TODO Auto-generated method stub        if (timer != null) {            timer.cancel();        }    }

5.Intent跳转传list集合

先把List<>改为ArrayList<>

ArrayList<Good> list=new ArrayList<Good>();

Intent intent = new Intent(MainActivity.this,InfoActivity.class);
  intent.putExtra("list", list);               startActivity(intent);

Intent intent = getIntent();

ArrayList<Good> list= (ArrayList<Good>) intent.getSerializableExtra("list");

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