Android编程开发音乐播放器实例

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  >
  <TextView
    android:id="@+id/name"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    />
  <SeekBar
    android:id="@+id/seekBar"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="5dp"
    />
  <LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="20dp"
    >
    <Button
      android:layout_width="40dp"
      android:layout_height="40dp"
      android:text="|◀"
      android:onClick="previous"
      />
    <Button
      android:id="@+id/pp"
      android:layout_width="40dp"
      android:layout_height="40dp"
      android:text="▶"
      android:onClick="pp"
      />
    <Button
      android:layout_width="40dp"
      android:layout_height="40dp"
      android:text="▶|"
      android:onClick="next"
      />
  </LinearLayout>
  <ListView
    android:id="@+id/list"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:padding="10dp"
  >
  <TextView
    android:id="@+id/mName"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:textSize="15sp"
    />
</LinearLayout>

package cn.test.audio;
import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.telephony.PhoneStateListener;
import android.telephony.TelephonyManager;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SeekBar;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.SeekBar.OnSeekBarChangeListener;
public class MainActivity extends Activity {
  private TextView nameTextView;
  private SeekBar seekBar;
  private ListView listView;
  private List<Map<String, String>> data;
  private int current;
  private MediaPlayer player;
  private Handler handler = new Handler();
  private Button ppButton;
  private boolean isPause;
  private boolean isStartTrackingTouch;
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    nameTextView = (TextView) findViewById(R.id.name);
    seekBar = (SeekBar) findViewById(R.id.seekBar);
    listView = (ListView) findViewById(R.id.list);
    ppButton = (Button) findViewById(R.id.pp);
    //创建一个音乐播放器
    player = new MediaPlayer();
    //显示音乐播放列表
    generateListView();
    //进度条监听器
    seekBar.setOnSeekBarChangeListener(new MySeekBarListener());
    //播放器监听器
    player.setOnCompletionListener(new MyPlayerListener());
    //意图过滤器
    IntentFilter filter = new IntentFilter();
    //播出电话暂停音乐播放
    filter.addAction("android.intent.action.NEW_OUTGOING_CALL");
    registerReceiver(new PhoneListener(), filter);
    //创建一个电话服务
    TelephonyManager manager = (TelephonyManager) getSystemService(TELEPHONY_SERVICE);
    //监听电话状态，接电话时停止播放
    manager.listen(new MyPhoneStateListener(), PhoneStateListener.LISTEN_CALL_STATE);
  }
  /*
   * 监听电话状态
   */
  private final class MyPhoneStateListener extends PhoneStateListener {
    public void onCallStateChanged(int state, String incomingNumber) {
      pause();
    }
  }
  /*
   * 播放器监听器
   */
  private final class MyPlayerListener implements OnCompletionListener {
    //歌曲播放完后自动播放下一首歌曲
    public void onCompletion(MediaPlayer mp) {
      next();
    }
  }
  /*
   * 下一首按钮
   */
  public void next(View view) {
    next();
  }
  /*
   * 前一首按钮
   */
  public void previous(View view) {
    previous();
  }
  /*
   * 播放前一首歌
   */
  private void previous() {
    current = current - 1 < 0 ? data.size() - 1 : current - 1;
    play();
  }
  /*
   * 播放下一首歌
   */
  private void next() {
    current = (current + 1) % data.size();
    play();
  }
  /*
   * 进度条监听器
   */
  private final class MySeekBarListener implements OnSeekBarChangeListener {
    //移动触发
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
    }
    //起始触发
    public void onStartTrackingTouch(SeekBar seekBar) {
      isStartTrackingTouch = true;
    }
    //结束触发
    public void onStopTrackingTouch(SeekBar seekBar) {
      player.seekTo(seekBar.getProgress());
      isStartTrackingTouch = false;
    }
  }
  /*
   * 显示音乐播放列表
   */
  private void generateListView() {
    List<File> list = new ArrayList<File>();
    //获取sdcard中的所有歌曲
    findAll(Environment.getExternalStorageDirectory(), list);
    //播放列表进行排序，字符顺序
    Collections.sort(list);
    data = new ArrayList<Map<String, String>>();
    for (File file : list) {
      Map<String, String> map = new HashMap<String, String>();
      map.put("name", file.getName());
      map.put("path", file.getAbsolutePath());
      data.add(map);
    }
    SimpleAdapter adapter = new SimpleAdapter(this, data, R.layout.item, new String[] { "name" }, new int[] { R.id.mName });
    listView.setAdapter(adapter);
    listView.setOnItemClickListener(new MyItemListener());
  }
  private final class MyItemListener implements OnItemClickListener {
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
      current = position;
      play();
    }
  }
  private void play() {
    try {
      //重播
      player.reset();
      //获取歌曲路径
      player.setDataSource(data.get(current).get("path"));
      //缓冲
      player.prepare();
      //开始播放
      player.start();
      //显示歌名
      nameTextView.setText(data.get(current).get("name"));
      //设置进度条长度
      seekBar.setMax(player.getDuration());
      //播放按钮样式
      ppButton.setText("||");
      //发送一个Runnable, handler收到之后就会执行run()方法
      handler.post(new Runnable() {
        public void run() {
          // 更新进度条状态
          if (!isStartTrackingTouch)
            seekBar.setProgress(player.getCurrentPosition());
          // 1秒之后再次发送
          handler.postDelayed(this, 1000);
        }
      });
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
  /**
   * 查找文件路径中所有mp3文件
   * @param file 要找的目录
   * @param list 用来装文件的List
   */
  private void findAll(File file, List<File> list) {
    File[] subFiles = file.listFiles();
    if (subFiles != null)
      for (File subFile : subFiles) {
        if (subFile.isFile() && subFile.getName().endsWith(".mp3"))
          list.add(subFile);
        else if (subFile.isDirectory())//如果是目录
          findAll(subFile, list); //递归
      }
  }
  /*
   * 暂停/播放按钮
   */
  public void pp(View view) {
    //默认从第一首歌曲开始播放
    if (!player.isPlaying() && !isPause) {
      play();
      return;
    }
    Button button = (Button) view;
    //暂停/播放按钮
    if ("||".equals(button.getText())) {
      pause();
      button.setText("▶");
    } else {
      resume();
      button.setText("||");
    }
  }
  /*
   * 开始操作
   */
  private void resume() {
    if (isPause) {
      player.start();
      isPause = false;
    }
  }
  /*
   * 暂停操作
   */
  private void pause() {
    if (player != null && player.isPlaying()) {
      player.pause();
      isPause = true;
    }
  }
  /*
   * 收到广播时暂停
   */
  private final class PhoneListener extends BroadcastReceiver {
    public void onReceive(Context context, Intent intent) {
      pause();
    }
  }
  /*
   * 恢复播放
   * @see android.app.Activity#onResume()
   */
  protected void onResume() {
    super.onResume();
    resume();
  }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="cn.itcast.audio"
   android:versionCode="1"
   android:versionName="1.0">
  <application android:icon="@drawable/icon" android:label="@string/app_name">
    <activity android:name=".MainActivity"
         android:label="@string/app_name">
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
  </application>
  <uses-sdk android:minSdkVersion="8" />
  <!-- 监听电话呼出 -->
  <uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS"/>
  <!-- 监听电话状态改变 -->
  <uses-permission android:name="android.permission.READ_PHONE_STATE" />
</manifest>