小型Mp3播放器

准备三张图片，名字分别为： play、pause、stop。

将一个名为Mp3的文件放入res/raw文件夹中。

在main.xml中：

<LinearLayout

xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:background="#000000"

android:gravity="center_horizontal"

android:orientation="vertical">

<TextView

android:id="@+id/info"

android:gravity="center_horizontal"

android:layout_marginTop="8dp"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:textColor="#ffffff"

        android:text="等待音频播放"/>

<LinearLayout

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_marginTop="20dp"

android:gravity="center_horizontal">

<ImageButton

android:id="@+id/play"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:src="@drawable/play"/>

<ImageButton

android:id="@+id/pause"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:src="@drawable/pause"/>

<ImageButton

android:id="@+id/stop"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:src="@drawable/stop"/>

</LinearLayout>

<SeekBar

android:id="@+id/seekbar"

android:layout_margin="8dp"

android:layout_width="fill_parent"

android:layout_height="wrap_content"/>

</LinearLayout>

在MyMediaPlayerDemo.java中：

package com.li.mediaplayer;

import android.app.Activity;

import android.media.MediaPlayer;

import android.media.MediaPlayer.OnCompletionListener;

import android.os.AsyncTask;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.ImageButton;

import android.widget.SeekBar;

import android.widget.SeekBar.OnSeekBarChangeListener;

import android.widget.TextView;

public class MyMediaPlayerDemo extends Activity {

private ImageButton play = null ;

private ImageButton pause = null ;

private ImageButton stop = null ;

private TextView info = null ;

private MediaPlayer myMediaPlayer = null ;

private SeekBar seekbar = null ;

private boolean playFlag = true ;  // 播放标记

private boolean pauseFlag = true ; // 暂停标记

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

super.setContentView(R.layout.main);

this.info = (TextView) super.findViewById(R.id.info) ;

this.play = (ImageButton) super.findViewById(R.id.play) ;

this.pause = (ImageButton) super.findViewById(R.id.pause) ;

this.stop = (ImageButton) super.findViewById(R.id.stop) ;

this.seekbar = (SeekBar) super.findViewById(R.id.seekbar) ;

this.play.setOnClickListener(new PlayOnClickListener()) ;

this.pause.setOnClickListener(new PauseOnClickListener()) ;

this.stop.setOnClickListener(new StopOnClickListener()) ;

this.seekbar.setOnSeekBarChangeListener(new OnSeekBarChangeListenerImpl()) ;

}

private class UpdateSeekBar extends AsyncTask<Integer, Integer, String> {

@Override

protected void onPostExecute(String result) {

super.onPostExecute(result);

}

@Override

protected void onProgressUpdate(Integer... values) {

MyMediaPlayerDemo.this.seekbar.setProgress(values[0]) ;

}

@Override

protected String doInBackground(Integer... params) {

while(MyMediaPlayerDemo.this.playFlag) {  // 播放的话，进度要增长

try {

Thread.sleep(params[0]) ;

} catch (InterruptedException e) {

}

this.publishProgress(MyMediaPlayerDemo.this.myMediaPlayer.getCurrentPosition()) ;

}

return null ;

}

}

private class PlayOnClickListener implements OnClickListener{

public void onClick(View v) {

MyMediaPlayerDemo.this.myMediaPlayer = MediaPlayer.create(

MyMediaPlayerDemo.this, R.raw.mp3);  // 要播放的文件

if (MyMediaPlayerDemo.this.myMediaPlayer != null) {

MyMediaPlayerDemo.this.myMediaPlayer.stop(); // 停止操作

}

MyMediaPlayerDemo.this.seekbar.setMax(MyMediaPlayerDemo.this.myMediaPlayer.getDuration()) ;  // 设置拖拽条的长度

UpdateSeekBar update = new UpdateSeekBar() ;

update.execute(1000) ;

MyMediaPlayerDemo.this.myMediaPlayer.setOnCompletionListener(new OnCompletionListener(){

public void onCompletion(MediaPlayer mp) {

MyMediaPlayerDemo.this.playFlag = false ; // 播放完毕

MyMediaPlayerDemo.this.myMediaPlayer.release() ;  // 释放资源

}}) ;

try {

MyMediaPlayerDemo.this.myMediaPlayer.prepare() ;

MyMediaPlayerDemo.this.myMediaPlayer.start() ;

MyMediaPlayerDemo.this.info.setText("正在播放音频文件...") ;

} catch (Exception e) {

MyMediaPlayerDemo.this.info.setText("文件播放出现异常，" + e) ;

}

}

}

private class PauseOnClickListener implements OnClickListener{

public void onClick(View v) {

if(MyMediaPlayerDemo.this.myMediaPlayer != null) {

if (MyMediaPlayerDemo.this.pauseFlag) { // 现在暂停

MyMediaPlayerDemo.this.myMediaPlayer.start();

MyMediaPlayerDemo.this.pauseFlag = false ;

} else {

MyMediaPlayerDemo.this.myMediaPlayer.pause(); // 暂停

MyMediaPlayerDemo.this.pauseFlag = true ;

}

}

}

}

private class StopOnClickListener implements OnClickListener{

public void onClick(View v) {

if(MyMediaPlayerDemo.this.myMediaPlayer != null) {

MyMediaPlayerDemo.this.myMediaPlayer.stop() ;  // 停止

MyMediaPlayerDemo.this.info.setText("停止播放音频文件...") ;

}

}

}

private class OnSeekBarChangeListenerImpl implements OnSeekBarChangeListener {

public void onProgressChanged(SeekBar seekBar, int progress,

boolean fromUser) {

}

public void onStartTrackingTouch(SeekBar seekBar) {

}

public void onStopTrackingTouch(SeekBar seekBar) {

MyMediaPlayerDemo.this.myMediaPlayer.seekTo(seekBar.getProgress()) ;

}

}

}