Android学习一、MediaPlayer播放音频
想要使用MediaPlayer播放音频和视频，首先必须了解MediaPlayer的状态问题。下面是Google提供的MediaPlayer的状态图，基本上只要明白了，在MediaPlayer的状态上。就不会出问题了。
还有什么不明白的，可以详细的看看Google提供的API。
要想用MediaPlayer所写的的音频播放程序健壮的话，不仅需要了解MediaPlayer的各种状态，还必须对MediaPlayer的各个监听事件和回调方法做出必要的设定。
可以根据自己的需要，设置不同的监听方法。
下面是Copy别人的代码，写的不错，搬来壮壮场面。
1、这是布局的文件main.xml
<?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="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="top"
android:orientation="horizontal" >
<Button
android:id="@+id/btnPlayUrl"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="播放网络音频" />
<Button
android:id="@+id/btnPause"
android:layout_width="80dip"
android:layout_height="wrap_content"
android:text="暂停" />
<Button
android:id="@+id/btnStop"
android:layout_width="80dip"
android:layout_height="wrap_content"
android:text="停止" />
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="top"
android:orientation="horizontal" >
<SeekBar
android:id="@+id/skbProgress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="1.0"
android:max="100"
android:paddingLeft="10dip"
android:paddingRight="10dip" />
</LinearLayout>
</LinearLayout>
2、Player.java 封装了MediaPlayer的播放
package com.tao.test;
import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnBufferingUpdateListener;
import android.media.MediaPlayer.OnCompletionListener;
import android.media.MediaPlayer.OnErrorListener;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.widget.SeekBar;
public class Player implements OnBufferingUpdateListener, OnCompletionListener,
MediaPlayer.OnPreparedListener ,OnErrorListener{
public MediaPlayer mediaPlayer;
private SeekBar skbProgress;
private Timer mTimer = new Timer();
public Player(SeekBar skbProgress) {
this.skbProgress = skbProgress;
try {
mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setOnBufferingUpdateListener(this);
mediaPlayer.setOnPreparedListener(this);
mediaPlayer.setOnCompletionListener(this);
} catch (Exception e) {
Log.e("mediaPlayer", "error", e);
}
mTimer.schedule(mTimerTask, 0, 1000);
}
/**
* 通过定时器和Handler来更新进度条
*/
TimerTask mTimerTask = new TimerTask() {
@Override
public void run() {
if (mediaPlayer == null)
return;
if (mediaPlayer.isPlaying() && skbProgress.isPressed() == false) {
handleProgress.sendEmptyMessage(0);
}
}
};
//处理消息
Handler handleProgress = new Handler() {
public void handleMessage(Message msg) {
int position = mediaPlayer.getCurrentPosition();
int duration = mediaPlayer.getDuration();
if (duration > 0) {
int pos = skbProgress.getMax() * position / duration;
skbProgress.setProgress(pos);
}
};
};
public void playUrl(String videoUrl) {
try {
mediaPlayer.reset();
mediaPlayer.setDataSource(videoUrl);
mediaPlayer.prepare();// prepare之后自动播放
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void pause() {
mediaPlayer.pause();
}
public void play() {
mediaPlayer.start();
}
public void stop() {
if (mediaPlayer != null) {
mediaPlayer.stop();
mediaPlayer.release();
mediaPlayer = null;
}
}
/**
* 通过onPrepared播放
*/
public void onPrepared(MediaPlayer arg0) {
arg0.start();
Log.e("mediaPlayer", "onPrepared");
}
public void onCompletion(MediaPlayer arg0) {
Log.e("mediaPlayer", "onCompletion");
}
public void onBufferingUpdate(MediaPlayer arg0, int bufferingProgress) {
skbProgress.setSecondaryProgress(bufferingProgress);
int currentProgress = skbProgress.getMax()
* mediaPlayer.getCurrentPosition() / mediaPlayer.getDuration();
Log.e(currentProgress + "% play", bufferingProgress + "% buffer");
}
public boolean onError(MediaPlayer mp, int what, int extra) {
return false;
}
}
3、TestMedia.java 测试用的Activity
package com.tao.test;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.SeekBar;
public class TestMedia extends Activity {
private Button btnPause, btnPlayUrl, btnStop;
private SeekBar skbProgress;
private Player player;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
this.setTitle("在线音乐播放---hellogv编写");
btnPlayUrl = (Button) this.findViewById(R.id.btnPlayUrl);
btnPlayUrl.setOnClickListener(new ClickEvent());
btnPause = (Button) this.findViewById(R.id.btnPause);
btnPause.setOnClickListener(new ClickEvent());
btnStop = (Button) this.findViewById(R.id.btnStop);
btnStop.setOnClickListener(new ClickEvent());
skbProgress = (SeekBar) this.findViewById(R.id.skbProgress);
skbProgress.setOnSeekBarChangeListener(new SeekBarChangeEvent());
player = new Player(skbProgress);
}
class ClickEvent implements OnClickListener {
public void onClick(View arg0) {
if (arg0 == btnPause) {
player.pause();
} else if (arg0 == btnPlayUrl) {
// 在百度MP3里随便搜索到的,大家可以试试别的链接
String url = "http://219.138.125.22/myweb/mp3/CMP3/JH19.MP3";
player.playUrl(url);
} else if (arg0 == btnStop) {
player.stop();
}
}
}
class SeekBarChangeEvent implements SeekBar.OnSeekBarChangeListener {
int progress;
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
// 原本是(progress/seekBar.getMax())*player.mediaPlayer.getDuration()
this.progress = progress * player.mediaPlayer.getDuration()
/ seekBar.getMax();
}
public void onStartTrackingTouch(SeekBar seekBar) {
}
public void onStopTrackingTouch(SeekBar seekBar) {
// seekTo()的参数是相对与影片时间的数字，而不是与seekBar.getMax()相对的数字
player.mediaPlayer.seekTo(progress);
}
}
}