Android应用开发-MP3音乐播放器代码实现（三）
Android应用开发-MP3音乐播放器代码实现（三）
2013年5月29 简、美音乐播放器开发记录
这篇博客是接着上一篇博客的，点击列表会进入播放的Activity,在这个Activity会接收到从前面的Activity传来的数据，在通过这些数据来启动服务来播放音乐，整个过程很简单，需要注意的是我们要接收的数据是哪些内容，还有我们向Service要传什么样的数据，这是根据自己的开发思路和需求来决定的，等一下你们会看到小巫到底往Service传了些什么东西，然而这些数据到底起什么作用，需要慢慢去体会，因为这是需要一点一点去调试的。
好了，下面贴一下整个Activity的实现代码，主要是播放的各种状态的实现，因为这个音乐播放器并没有完全开发完，所以朋友们需要弄清楚这一点。如果对代码的实现有不清楚的，可以给小巫留言，小巫有空一定给大家解答。
PlayerActivity.java代码：
package com.wwj.sb.activity;
import java.util.List;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;
import android.widget.Toast;
import com.wwj.sb.domain.AppConstant;
import com.wwj.sb.domain.Mp3Info;
import com.wwj.sb.utils.MediaUtil;
/**
* 播放音乐界面
* @author wwj
* 从主界面传递过来歌曲的Id、歌曲名、歌手、歌曲路径、播放状态
*/
public class PlayerActivity extends Activity{
private TextView musicTitle = null;
private TextView musicArtist = null;
private Button previousBtn; // 上一首
private Button repeatBtn; // 重复（单曲循环、全部循环）
private Button playBtn; // 播放（播放、暂停）
private Button shuffleBtn; // 随机播放
private Button nextBtn; // 下一首
private Button searchBtn; //查找歌曲
private Button queueBtn; //歌曲列表
private SeekBar music_progressBar; //歌曲进度
private TextView currentProgress; //当前进度消耗的时间
private TextView finalProgress; //歌曲时间
private String title; //歌曲标题
private String artist; //歌曲艺术家
private String url; //歌曲路径
private int listPosition; //播放歌曲在mp3Infos的位置
private int currentTime; //当前歌曲播放时间
private int duration; //歌曲长度
private int flag; //播放标识
private int repeatState;
private final int isCurrentRepeat = 1; // 单曲循环
private final int isAllRepeat = 2; // 全部循环
private final int isNoneRepeat = 3; // 无重复播放
private boolean isPlaying; // 正在播放
private boolean isPause; // 暂停
private boolean isNoneShuffle; // 顺序播放
private boolean isShuffle; // 随机播放
private List mp3Infos;
private PlayerReceiver playerReceiver;
public static final String UPDATE_ACTION = "com.wwj.action.UPDATE_ACTION"; //更新动作
public static final String CTL_ACTION = "com.wwj.action.CTL_ACTION"; //控制动作
public static final String MUSIC_CURRENT = "com.wwj.action.MUSIC_CURRENT"; //音乐当前时间改变动作
public static final String MUSIC_DURATION = "com.wwj.action.MUSIC_DURATION";//音乐播放长度改变动作
public static final String MUSIC_PLAYING = "com.wwj.action.MUSIC_PLAYING"; //音乐正在播放动作
public static final String REPEAT_ACTION = "com.wwj.action.REPEAT_ACTION"; //音乐重复播放动作
public static final String SHUFFLE_ACTION = "com.wwj.action.SHUFFLE_ACTION";//音乐随机播放动作
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.play_activity_layout);
musicTitle = (TextView) findViewById(R.id.musicTitle);
musicArtist = (TextView) findViewById(R.id.musicArtist);
findViewById();
setViewOnclickListener();
mp3Infos = MediaUtil.getMp3Infos(PlayerActivity.this);
playerReceiver = new PlayerReceiver();
IntentFilter filter = new IntentFilter();
filter.addAction(UPDATE_ACTION);
filter.addAction(MUSIC_CURRENT);
filter.addAction(MUSIC_DURATION);
registerReceiver(playerReceiver, filter);
}
/**
* 从界面上根据id获取按钮
*/
private void findViewById() {
previousBtn = (Button) findViewById(R.id.previous_music);
repeatBtn = (Button) findViewById(R.id.repeat_music);
playBtn = (Button) findViewById(R.id.play_music);
shuffleBtn = (Button) findViewById(R.id.shuffle_music);
nextBtn = (Button) findViewById(R.id.next_music);
searchBtn = (Button) findViewById(R.id.search_music);
queueBtn = (Button) findViewById(R.id.play_queue);
music_progressBar = (SeekBar) findViewById(R.id.audioTrack);
currentProgress = (TextView) findViewById(R.id.current_progress);
finalProgress = (TextView) findViewById(R.id.final_progress);
}
/**
* 给每一个按钮设置监听器
*/
private void setViewOnclickListener() {
ViewOnclickListener ViewOnClickListener = new ViewOnclickListener();
previousBtn.setOnClickListener(ViewOnClickListener);
repeatBtn.setOnClickListener(ViewOnClickListener);
playBtn.setOnClickListener(ViewOnClickListener);
shuffleBtn.setOnClickListener(ViewOnClickListener);
nextBtn.setOnClickListener(ViewOnClickListener);
searchBtn.setOnClickListener(ViewOnClickListener);
queueBtn.setOnClickListener(ViewOnClickListener);
music_progressBar.setOnSeekBarChangeListener(new SeekBarChangeListener());
}
/**
* 在OnResume中初始化和接收Activity数据
*/
@Override
protected void onResume() {
super.onResume();
Intent intent = getIntent();
Bundle bundle = intent.getExtras();
title = bundle.getString("title");
artist = bundle.getString("artist");
url = bundle.getString("url");
listPosition = bundle.getInt("listPosition");
repeatState = bundle.getInt("repeatState");
isShuffle = bundle.getBoolean("shuffleState");
flag = bundle.getInt("MSG");
currentTime = bundle.getInt("currentTime");
duration = bundle.getInt("duration");
initView();
}
/**
* 初始化界面
*/
public void initView() {
musicTitle.setText(title);
musicArtist.setText(artist);
music_progressBar.setProgress(currentTime);
music_progressBar.setMax(duration);
switch (repeatState) {
case isCurrentRepeat: // 单曲循环
shuffleBtn.setClickable(false);
repeatBtn.setBackgroundResource(R.drawable.repeat_current_selector);
break;
case isAllRepeat: // 全部循环
shuffleBtn.setClickable(false);
repeatBtn.setBackgroundResource(R.drawable.repeat_all_selector);
break;
case isNoneRepeat: // 无重复
shuffleBtn.setClickable(true);
repeatBtn.setBackgroundResource(R.drawable.repeat_none_selector);
break;
}
if(isShuffle) {
isNoneShuffle = false;
shuffleBtn.setBackgroundResource(R.drawable.shuffle_selector);
repeatBtn.setClickable(false);
} else {
isNoneShuffle = true;
shuffleBtn.setBackgroundResource(R.drawable.shuffle_none_selector);
repeatBtn.setClickable(true);
}
if(flag == AppConstant.PlayerMsg.PLAYING_MSG) { //如果播放信息是正在播放
Toast.makeText(PlayerActivity.this, "正在播放--" + title, 1).show();
}
else if(flag == AppConstant.PlayerMsg.PLAY_MSG) { //如果是点击列表播放歌曲的话
play();
}
playBtn.setBackgroundResource(R.drawable.play_selector);
isPlaying = true;
isPause = false;
}
/**
* 反注册广播
*/
@Override
protected void onStop() {
super.onStop();
unregisterReceiver(playerReceiver);
}
@Override
protected void onDestroy() {
super.onDestroy();
}
/**
* 控件点击事件
* @author wwj
*
*/
private class ViewOnclickListener implements OnClickListener {
Intent intent = new Intent();
@Override
public void onClick(View v) {
switch(v.getId()) {
case R.id.play_music:
if (isPlaying) {
playBtn.setBackgroundResource(R.drawable.pause_selector);
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("MSG", AppConstant.PlayerMsg.PAUSE_MSG);
startService(intent);
isPlaying = false;
isPause = true;
} else if (isPause) {
playBtn.setBackgroundResource(R.drawable.play_selector);
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("MSG", AppConstant.PlayerMsg.CONTINUE_MSG);
startService(intent);
isPause = false;
isPlaying = true;
}
break;
case R.id.previous_music: //上一首歌曲
previous_music();
break;
case R.id.next_music: //下一首歌曲
next_music();
break;
case R.id.repeat_music: //重复播放音乐
if (repeatState == isNoneRepeat) {
repeat_one();
shuffleBtn.setClickable(false); //是随机播放变为不可点击状态
repeatState = isCurrentRepeat;
} else if (repeatState == isCurrentRepeat) {
repeat_all();
shuffleBtn.setClickable(false);
repeatState = isAllRepeat;
} else if (repeatState == isAllRepeat) {
repeat_none();
shuffleBtn.setClickable(true);
repeatState = isNoneRepeat;
}
Intent intent = new Intent(REPEAT_ACTION);
switch (repeatState) {
case isCurrentRepeat: // 单曲循环
repeatBtn
.setBackgroundResource(R.drawable.repeat_current_selector);
Toast.makeText(PlayerActivity.this, R.string.repeat_current,
Toast.LENGTH_SHORT).show();
intent.putExtra("repeatState", isCurrentRepeat);
sendBroadcast(intent);
break;
case isAllRepeat: // 全部循环
repeatBtn
.setBackgroundResource(R.drawable.repeat_all_selector);
Toast.makeText(PlayerActivity.this, R.string.repeat_all,
Toast.LENGTH_SHORT).show();
intent.putExtra("repeatState", isAllRepeat);
sendBroadcast(intent);
break;
case isNoneRepeat: // 无重复
repeatBtn
.setBackgroundResource(R.drawable.repeat_none_selector);
Toast.makeText(PlayerActivity.this, R.string.repeat_none,
Toast.LENGTH_SHORT).show();
intent.putExtra("repeatState", isNoneRepeat);
break;
}
break;
case R.id.shuffle_music: //随机播放状态
Intent shuffleIntent = new Intent(SHUFFLE_ACTION);
if (isNoneShuffle) { //如果当前状态为非随机播放，点击按钮之后改变状态为随机播放
shuffleBtn
.setBackgroundResource(R.drawable.shuffle_selector);
Toast.makeText(PlayerActivity.this, R.string.shuffle,
Toast.LENGTH_SHORT).show();
isNoneShuffle = false;
isShuffle = true;
shuffleMusic();
repeatBtn.setClickable(false);
shuffleIntent.putExtra("shuffleState", true);
sendBroadcast(shuffleIntent);
} else if (isShuffle) {
shuffleBtn
.setBackgroundResource(R.drawable.shuffle_none_selector);
Toast.makeText(PlayerActivity.this, R.string.shuffle_none,
Toast.LENGTH_SHORT).show();
isShuffle = false;
isNoneShuffle = true;
repeatBtn.setClickable(true);
shuffleIntent.putExtra("shuffleState", false);
sendBroadcast(shuffleIntent);
}
break;
}
}
}
/**
* 实现监听Seekbar的类
* @author wwj
*
*/
private class SeekBarChangeListener implements OnSeekBarChangeListener {
@Override
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
if(fromUser) {
audioTrackChange(progress); //用户控制进度的改变
}
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
}
/**
* 播放音乐
*/
public void play() {
//开始播放的时候为顺序播放
repeat_none();
Intent intent = new Intent();
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("url", url);
intent.putExtra("listPosition", listPosition);
intent.putExtra("MSG", flag);
startService(intent);
}
/**
* 随机播放
*/
public void shuffleMusic() {
Intent intent = new Intent(CTL_ACTION);
intent.putExtra("control", 4);
sendBroadcast(intent);
}
public void audioTrackChange(int progress) {
Intent intent = new Intent();
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("url", url);
intent.putExtra("listPosition", listPosition);
if(isPause) {
intent.putExtra("MSG", AppConstant.PlayerMsg.PAUSE_MSG);
}
else {
intent.putExtra("MSG", AppConstant.PlayerMsg.PROGRESS_CHANGE);
}
intent.putExtra("progress", progress);
startService(intent);
}
/**
* 单曲循环
*/
public void repeat_one() {
Intent intent = new Intent(CTL_ACTION);
intent.putExtra("control", 1);
sendBroadcast(intent);
}
/**
* 全部循环
*/
public void repeat_all() {
Intent intent = new Intent(CTL_ACTION);
intent.putExtra("control", 2);
sendBroadcast(intent);
}
/**
* 顺序播放
*/
public void repeat_none() {
Intent intent = new Intent(CTL_ACTION);
intent.putExtra("control", 3);
sendBroadcast(intent);
}
/**
* 上一首
*/
public void previous_music() {
playBtn.setBackgroundResource(R.drawable.play_selector);
listPosition = listPosition - 1;
if(listPosition >= 0) {
Mp3Info mp3Info = mp3Infos.get(listPosition); //上一首MP3
musicTitle.setText(mp3Info.getTitle());
musicArtist.setText(mp3Info.getArtist());
url = mp3Info.getUrl();
Intent intent = new Intent();
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("url", mp3Info.getUrl());
intent.putExtra("listPosition", listPosition);
intent.putExtra("MSG", AppConstant.PlayerMsg.PRIVIOUS_MSG);
startService(intent);
}
else {
Toast.makeText(PlayerActivity.this, "没有上一首了", Toast.LENGTH_SHORT).show();
}
}
/**
* 下一首
*/
public void next_music() {
playBtn.setBackgroundResource(R.drawable.play_selector);
listPosition = listPosition + 1;
if(listPosition <= mp3Infos.size() - 1) {
Mp3Info mp3Info = mp3Infos.get(listPosition);
url = mp3Info.getUrl();
musicTitle.setText(mp3Info.getTitle());
musicArtist.setText(mp3Info.getArtist());
Intent intent = new Intent();
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("url", mp3Info.getUrl());
intent.putExtra("listPosition", listPosition);
intent.putExtra("MSG", AppConstant.PlayerMsg.NEXT_MSG);
startService(intent);
} else {
Toast.makeText(PlayerActivity.this, "没有下一首了", Toast.LENGTH_SHORT).show();
}
}
/**
* 用来接收从service传回来的广播的内部类
* @author wwj
*
*/
public class PlayerReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if(action.equals(MUSIC_CURRENT)) {
currentTime = intent.getIntExtra("currentTime", -1);
currentProgress.setText(MediaUtil.formatTime(currentTime));
music_progressBar.setProgress(currentTime);
} else if(action.equals(MUSIC_DURATION)) {
int duration = intent.getIntExtra("duration", -1);
music_progressBar.setMax(duration);
finalProgress.setText(MediaUtil.formatTime(duration));
} else if(action.equals(UPDATE_ACTION)) {
//获取Intent中的current消息，current代表当前正在播放的歌曲
listPosition = intent.getIntExtra("current", -1);
url = mp3Infos.get(listPosition).getUrl();
if(listPosition >= 0) {
musicTitle.setText(mp3Infos.get(listPosition).getTitle());
musicArtist.setText(mp3Infos.get(listPosition).getArtist());
}
if(listPosition == 0) {
finalProgress.setText(MediaUtil.formatTime(mp3Infos.get(listPosition).getDuration()));
playBtn.setBackgroundResource(R.drawable.pause_selector);
isPause = true;
}
}
}
}
}
以上代码主要有以下几点实现：
1. 播放状态（上一首、下一首、暂停音乐、播放音乐、重复播放、随机播放）
2. 进度更新（自定义Seekbar，Seekbar触发时间控制音乐播放的位置）
3. 接收来自Service的广播，对播放时间，歌曲信息的UI更新。
要注意的地方：
1. 在onResume里接收来自HomeActivity里通过Intent传过来的数据，它是保存在bundle当中的，所以可以通过Bundle来取数据。
2. 通过startSercice来启动服务，在启动之前我们往服务传的数据
/**
* 播放音乐
*/
public void play() {
//开始播放的时候为顺序播放
repeat_none();
Intent intent = new Intent();
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("url", url);
intent.putExtra("listPosition", listPosition);
intent.putExtra("MSG", flag);
startService(intent);
}可以看到只有url（音乐播放路径）、listPosition(列表的点击位置，也就是mp3Infos的位置）、MSG(代表播放信息）。这几个是来控制播放的，在Service会很清楚看到这几个参数的作用。这会在下一篇博客中介绍。