Android OpenGL 2.1.4 简易播放器实现

 MainActivity.java

package com.fisnail;

import java.io.IOException;

import android.app.Activity;
import android.content.Context;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
/**
 * 
 * @author 粪豆的蜗牛([email protected])
 *
 */
public class MainActivity extends Activity implements OnClickListener{
	/**
	 * 播放按钮
	 */
	private Button btn_id_play;
	/**
	 * 暂停按钮
	 */
	private Button btn_id_pause;
	/**
	 * 停止按钮
	 */
	private Button btn_id_stop;
	/**
	 * 增大音量
	 */
	private Button btn_id_raise;
	/**
	 * 减小音量
	 */
	private Button btn_id_lower;
	/**
	 * 声明MediaPlayer引用
	 */
	private MediaPlayer mediaPlayer;
	/**
	 * 声明AudioManager引用
	 */
	private AudioManager audioManager;
	/**
	 * 最大音量值
	 */
	private int maxVolume;
	/**
	 * 当前音量值
	 */
	private int currentVolume;
	/**
	 * 每次调整的音量幅度
	 */
	private int stepVolume;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        btn_id_play =(Button) findViewById(R.id.btn_main_play);
        btn_id_play.setOnClickListener(this);
        
        btn_id_pause =(Button) findViewById(R.id.btn_main_pause);
        btn_id_pause.setOnClickListener(this);
       
        btn_id_stop =(Button) findViewById(R.id.btn_main_stop);
        btn_id_stop.setOnClickListener(this);
        
        btn_id_raise =(Button) findViewById(R.id.btn_main_raise);
        btn_id_raise.setOnClickListener(this);
        
        btn_id_lower =(Button) findViewById(R.id.btn_main_lower);
        btn_id_lower.setOnClickListener(this);
        
        mediaPlayer = new MediaPlayer();//创建MediaPlayer对象
        
        try {
			mediaPlayer.setDataSource("/sdcard/test.ogg");//设置要播放的资源
			mediaPlayer.prepare();//进行缓冲准备
		} catch (IOException e) {
			e.printStackTrace();
		}
        //创建AudioManager对象引用
        audioManager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
        //获取最大音乐音量
        maxVolume = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
        stepVolume =maxVolume/10;//每次调整音量幅度
        
    }
	@Override
	public void onClick(View v) {
		int tempVolume =0;
		switch (v.getId()) {
		
		case R.id.btn_main_play:
			mediaPlayer.start();//播放音乐
			Toast.makeText(getBaseContext(), "开始播放音乐", Toast.LENGTH_SHORT).show();
			break;
			
		case R.id.btn_main_pause:
			mediaPlayer.pause();//暂停音乐
			Toast.makeText(getBaseContext(), "暂停播放音乐", Toast.LENGTH_SHORT).show();
			break;
			
		case R.id.btn_main_stop:
			mediaPlayer.stop();
			try {
				mediaPlayer.prepare();//进入准备状态
			} catch (IOException e) {
				e.printStackTrace();
			}
			Toast.makeText(getBaseContext(), "停止播放音乐",
					Toast.LENGTH_SHORT).show();
			break;
			
		case R.id.btn_main_raise:
			//获取当前音量
			currentVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
			tempVolume =currentVolume+stepVolume;
			//最大音量不得大于系统最大音量
			currentVolume = tempVolume>maxVolume?maxVolume:tempVolume;
			/**
			 * void android.media.AudioManager.setStreamVolume
			 * (int streamType, int index, int flags)
			 * streamType:声音类型
			 * index:设置音量的索引值，音量大小
			 * flags:标记，默认设置为AudioManager.FLAG_PLAY_SOUND
			 */
			audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, 
					currentVolume, AudioManager.FLAG_PLAY_SOUND);
			Toast.makeText(getBaseContext(), "增大音量"+currentVolume, 
					Toast.LENGTH_SHORT).show();
			break;
			
		case R.id.btn_main_lower:
			//获取当前音量
			currentVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
			tempVolume =currentVolume-stepVolume;
			currentVolume = tempVolume>0?tempVolume:0;//最大音量不得大于系统最大音量
			audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, currentVolume,
					AudioManager.FLAG_PLAY_SOUND);
			Toast.makeText(getBaseContext(), "减小音量"+currentVolume,
					Toast.LENGTH_SHORT).show();
			break;

		}
	}
	
	
 


    
}

 AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.fisnail"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.fisnail.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>

</manifest>

 activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >
    
	<!--title  -->
    <TextView
        android:id="@+id/tv_main_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/tv_main_title_text"
        android:layout_centerHorizontal="true" />
    
    <!--播放按钮  -->
    <Button android:id="@+id/btn_main_play"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/tv_main_title"
        android:text="@string/btn_main_play_text"/>
    
    <!--暂停按钮  -->
    <Button android:id="@+id/btn_main_pause"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/btn_main_play"
        android:text="@string/btn_main_pause_text"/>
    
    <!--停止按钮  -->
    <Button android:id="@+id/btn_main_stop"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/btn_main_pause"
        android:text="@string/btn_main_stop_text"/>
    
    <!--增大音量按钮  -->
    <Button android:id="@+id/btn_main_raise"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/btn_main_stop"
        android:text="@string/btn_main_raise_text"/>
    <!--减小音量按钮  -->
    <Button android:id="@+id/btn_main_lower"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/btn_main_raise"
        android:text="@string/btn_main_lower_text"/>

</RelativeLayout>

 strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">简易播放器</string>
    <string name="action_settings">Settings</string>
    <string name="hello_world">Hello world!</string>
    <string name="tv_main_title_text">简单音乐播放器</string>
    <string name="btn_main_play_text">播放音乐</string>
    <string name="btn_main_pause_text">暂停音乐</string>
    <string name="btn_main_stop_text">停止音乐</string>
    <string name="btn_main_raise_text">增大音量</string>
    <string name="btn_main_lower_text">减小音量</string>

</resources>

 遇到的问题：

播放音乐过程中，如果当音量减少至0时，报E/MP3Extractor(34): Unable to resync. Signalling end of stream.错,百度谷歌后，有网友说是Android2.2的BUG,有网友说，是少权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>

加入这两个权限后，虽然当音量减少至0时不再报错，但是音频文件，还是会偶尔退出，报错依旧是：E/MP3Extractor(34): Unable to resync. Signalling end of stream.继续各种查，网上有网友建议将.mp3文件转换成.ogg文件，试后发现问题依旧存在。

PS;这个问题还未解决，希望网友给予提示，谢谢！