ANDROID_MARS学习笔记_S01原始版_023_MP3PLAYER005_用广播BroacastReciever实现后台播放不更新歌词
一、代码流程
1.自定义一个AppConstant.LRC_MESSAGE_ACTION字符串表示广播"更新歌词"
2.在PlayerActivity的onResume()注册BroadcastReceiver,在onPause解除BroadcastReceiver
3.自定义LrcMessageBroadcastReceiver继承BroadcastReceiver,在onCreate()通过intent获取歌词,更新UI
4.所有更新歌词的操作移到PlayerService中
二、代码
1.xml
2.java
(1)PlayerActivity.java
package tony.mp3player; import tony.model.Mp3Info;
import tony.mp3player.service.PlayerService;
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.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageButton;
import android.widget.TextView; //更新歌词的工作不再在activity中完成,Activity只被动地接收service的广播以更新歌词,
//原来的相关歌词操作挪到service中完成
public class PlayerActivity extends Activity { private ImageButton beginBtn = null;
private ImageButton pauseBtn = null;
private ImageButton stopBtn = null; private TextView lrcTextView = null;
private Mp3Info info = null; private IntentFilter intentFilter = null;
private BroadcastReceiver receiver = null; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.player);
Intent intent = getIntent();
info = (Mp3Info) intent.getSerializableExtra("mp3Info");
beginBtn = (ImageButton) findViewById(R.id.begin);
pauseBtn = (ImageButton) findViewById(R.id.pause);
stopBtn = (ImageButton) findViewById(R.id.stop);
lrcTextView = (TextView) findViewById(R.id.lrcText); beginBtn.setOnClickListener(new BeginListener());
pauseBtn.setOnClickListener(new PauseListener());
stopBtn.setOnClickListener(new StopListener());
} @Override
protected void onPause() {
super.onPause();
unregisterReceiver(receiver);
} @Override
protected void onResume() {
super.onResume();
receiver = new LrcMessageBroadcastReceiver();
registerReceiver(receiver, getIntentFilter());
} private IntentFilter getIntentFilter() {
if(intentFilter == null) {
intentFilter = new IntentFilter();
intentFilter.addAction(AppConstant.LRC_MESSAGE_ACTION);
}
return intentFilter;
} /**
* 广播接收器,主要接收service放送的广播,并且更新UI,也就是放置歌词 的textview
* @author T
*
*/
class LrcMessageBroadcastReceiver extends BroadcastReceiver {
public void onReceive(Context context, Intent intent) {
String lrcMessage = intent.getStringExtra("lrcMessage");
lrcTextView.setText(lrcMessage);
}
} class BeginListener implements OnClickListener {
@Override
public void onClick(View v) {
Intent intent = new Intent();
intent.putExtra("mp3Info", info);
intent.putExtra("MSG", AppConstant.PlayerMsg.PLAY_MSG);
intent.setClass(PlayerActivity2.this, PlayerService.class);
startService(intent);
}
} class PauseListener implements OnClickListener {
@Override
public void onClick(View v) {
//通知Service暂停播放MP3
Intent intent = new Intent();
intent.putExtra("MSG", AppConstant.PlayerMsg.PAUSE_MSG);
intent.setClass(PlayerActivity2.this, PlayerService.class);
startService(intent);
}
} class StopListener implements OnClickListener {
@Override
public void onClick(View v) {
//通知Service停止播放MP3文件
Intent intent = new Intent();
intent.putExtra("MSG", AppConstant.PlayerMsg.STOP_MSG);
intent.setClass(PlayerActivity2.this, PlayerService.class);
startService(intent);
}
}
}
(2)PlayerService.java
package tony.mp3player.service; import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.List;
import java.util.Queue; import tony.model.Mp3Info;
import tony.mp3player.AppConstant;
import tony.mp3player.LrcProcessor;
import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Environment;
import android.os.Handler;
import android.os.IBinder; public class PlayerService extends Service { private boolean isPlaying = false;
private boolean isPause = false;
private boolean isReleased = false;
private MediaPlayer mediaPlayer = null; private Mp3Info info = null;
private List<Queue> queues = null;
private Handler handler = new Handler();
private UpdateTimeCallback updateTimeCallback = null;
private long begin = 0;
private long nextTimeMill = 0;
private long currentTimeMill = 0;
private String msg = null;
private long pauseTimeMills = 0; @Override
public IBinder onBind(Intent intent) {
return null;
} @Override
public int onStartCommand(Intent intent, int flags, int startId) {
info = (Mp3Info) intent.getSerializableExtra("mp3Info");
int MSG = intent.getIntExtra("MSG", 0);
if(info != null) {
if(MSG == AppConstant.PlayerMsg.PLAY_MSG) {
play(info);
}
} else {
if(MSG == AppConstant.PlayerMsg.PAUSE_MSG) {
pause();
}
else if(MSG == AppConstant.PlayerMsg.STOP_MSG) {
stop();
}
}
return super.onStartCommand(intent, flags, startId);
} /**
* 根据歌词文件的名字,来读取歌词文件当中的信息
* @param lrcName
*/
private void prepareLrc(String lrcName) {
try {
InputStream inputStream;
inputStream = new FileInputStream(Environment.getExternalStorageDirectory().getAbsolutePath() +
File.separator + "mp3" + File.separator + info.getLrcName());
LrcProcessor lrcProcessor = new LrcProcessor();
queues = lrcProcessor.process(inputStream);
updateTimeCallback = new UpdateTimeCallback(queues);
begin = 0;
currentTimeMill = 0;
nextTimeMill = 0;
} catch (Exception e) {
e.printStackTrace();
}
} class UpdateTimeCallback implements Runnable{
Queue<Long> times = null;
Queue<String> msgs = null; public UpdateTimeCallback(List<Queue> queues) {
this.times = queues.get(0);
this.msgs = queues.get(1);
} @Override
public void run() {
//计算偏移量,也就是说从开始播放MP3到现在为止,共消耗了多少时间,以毫秒为单位
long offset = System.currentTimeMillis() - begin;
if(currentTimeMill == 0) {//刚开始播放时,调用prepareLrc(),在其中设置currentTimeMill=0
nextTimeMill = times.poll();
msg = msgs.poll();
}
//歌词的显示是如下:例如
//[00:01.00]Look
//[00:03.00]Up
//[00:06.00]Down
//则在第1~3秒间是显示“look”,在第3~6秒间是显示"Up",在第6秒到下一个时间点显示"Down"
if(offset >= nextTimeMill) {
//发送广播,把此刻应该显示的歌词传出去
Intent intent = new Intent();
intent.setAction(AppConstant.LRC_MESSAGE_ACTION);
intent.putExtra("lrcMessage", msg);
sendBroadcast(intent);
msg = msgs.poll();
nextTimeMill = times.poll();
}
currentTimeMill = currentTimeMill + 100;
//在run方法里调用postDelayed,则会形成循环,每0.01秒执行一次线程
handler.postDelayed(updateTimeCallback, 100);
}
} private void play(Mp3Info info) {
if(!isPlaying) {
String path = getMp3Path(info);
mediaPlayer = MediaPlayer.create(this, Uri.parse("file://" + path));
mediaPlayer.setLooping(false);
mediaPlayer.start();
isPlaying = true;
isReleased = false; prepareLrc(info.getLrcName());
handler.postDelayed(updateTimeCallback, 5);
begin = System.currentTimeMillis();
}
} private void pause() {
if(mediaPlayer != null) {
if(!isReleased){
if(!isPause) {
mediaPlayer.pause();
//不再更新歌词
handler.removeCallbacks(updateTimeCallback);
//用来下面代码计算暂停了多久
pauseTimeMills = System.currentTimeMillis();
} else {
mediaPlayer.start();
handler.postDelayed(updateTimeCallback, 5);
//因为下面的时间偏移是这样计算的offset = System.currentTimeMillis() - begin;
//所以要把暂停的时间加到begin里去,
begin = System.currentTimeMillis() - pauseTimeMills + begin;
}
isPause = !isPause;
isPlaying = !isPlaying;
}
}
} private void stop() {
if(mediaPlayer != null) {
if(isPlaying) {
if(!isReleased) {
//从Handler当中移除updateTimeCallback
handler.removeCallbacks(updateTimeCallback);
mediaPlayer.stop();
mediaPlayer.release();
isReleased = true;
isPlaying = false;
}
}
}
} private String getMp3Path(Mp3Info mp3Info) {
String SDCardRoot = Environment.getExternalStorageDirectory()
.getAbsolutePath();
String path = SDCardRoot + File.separator + "mp3" + File.separator
+ mp3Info.getMp3Name();
return path;
}
}
ANDROID_MARS学习笔记_S01原始版_023_MP3PLAYER005_用广播BroacastReciever实现后台播放不更新歌词的更多相关文章
- ANDROID_MARS学习笔记_S01原始版_005_RadioGroup\CheckBox\Toast
一.代码 1.xml(1)radio.xml <?xml version="1.0" encoding="utf-8"?> <LinearLa ...
- ANDROID_MARS学习笔记_S01原始版_004_TableLayout
1.xml <?xml version="1.0" encoding="utf-8"?> <TableLayout xmlns:android ...
- ANDROID_MARS学习笔记_S01原始版_003_对话框
1.AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <manifest ...
- ANDROID_MARS学习笔记_S01原始版_002_实现计算乘积及menu应用
一.代码 1.xml(1)activity_main.xml <RelativeLayout xmlns:android="http://schemas.android.com/apk ...
- ANDROID_MARS学习笔记_S01原始版_001_Intent
一.Intent简介 二.代码 1.activity_main.xml <RelativeLayout xmlns:android="http://schemas.android.co ...
- ANDROID_MARS学习笔记_S01原始版_023_MP3PLAYER004_同步显示歌词
一.流程分析 1.点击播放按钮,会根据lrc名调用LrcProcessor的process()分析歌词文件,得到时间队列和歌词队列 2.new一个hander,把时间队列和歌词队列传给自定义的线程类U ...
- ANDROID_MARS学习笔记_S01原始版_023_MP3PLAYER003_播放mp3
一.简介 1.在onListItemClick中实现点击条目时,跳转到PlayerActivity,mp3info通过Intent传给PlayerActivity 2.PlayerActivity通过 ...
- ANDROID_MARS学习笔记_S01原始版_022_MP3PLAYER002_本地及remote标签
一.简介 1.在main.xml中用TabHost.TabWidget.FrameLayout标签作布局 2.在MainActivity中生成TabHost.TabSpec,调用setIndicato ...
- ANDROID_MARS学习笔记_S01原始版_021_MP3PLAYER001_下载mp3文件
一.简介 1.在onListItemClick()中new Intent,Intent以存储序列化后的mp2Info对象作为参数,启动serivce 2.DownloadService在onStart ...
随机推荐
- centos 6.4 Apache 配置 flv mp4.h264 流媒体拖动
http://blog.csdn.net/xst686/article/details/9763995 加入流媒体扩展后要重启 httpd flv 流媒体 <textarea style=&qu ...
- MyEclipse build path修改问题
- 多个UITableView横向切换的简单实现(有点类似网易新闻)
实现多列表切换,位置监控,置顶等功能. 方法一: 创建一个TableView,在切换的时候请求各类目需要的数据,然后刷新列表,通过动画模拟出滑动效果. #import <UIKit/UIKit. ...
- POJ 2777(线段树)
Count Color Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 42507 Accepted: 12856 Des ...
- HDOJ 1024 Max Sum Plus Plus -- 动态规划
题目地址:http://acm.hdu.edu.cn/showproblem.php?pid=1024 Problem Description Now I think you have got an ...
- jQuery按钮复制文本内容
这种方法能保证文本内容被复制到windows剪切板,代码示例是复制url <!doctype html> <html> <head> <meta charse ...
- tomcat 192.168.1.110?不烦吗?
最近做一个在线播放器,因为要用到网络服务器做在线播放,又不想直接在本地用tomcat做实验,因为没有真实感. so,手边两台电脑,同时连在局域网. 客户端,笔记本,ip1:192.168.1.101 ...
- 图片裁切插件jCrop的使用心得(一)
之前,项目经理为了提升用户体验让我在之前图片上传功能的基础上实现图片的裁切功能,作为一个前端小白来说听了这个需求心里一紧,毕竟没有做过,于是跟项目经理商量要先做下调研.在一上午的调研中发现了jCrop ...
- MYSQL Error 2006HY000:MySQL server has gone away的解决方案
MySQL server has gone away有几种情况. 1.应用程序(比如PHP)长时间的执行批量的MYSQL语句. 最常见的就是采集或者新旧数据转化. 解决方案: 在my.cnf文件中添加 ...
- ZeroMQ/jzmq安装使用
环境: No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 12.04.2 LTS Release: 12 ...