Android開發之控制手機音頻

本實例通過MediaPlayer播放一首音樂並通過AudioManager控制手機音頻，關於AudioManager的詳解可參照：Android開發之AudioManager（音頻管理器）詳解

程序運行效果圖：

實例代碼：

package com.jph.audiomanagerdemo;

import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.app.Activity;
import android.app.Service;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.ToggleButton;
/**
 * Describe:

 * 控制數據音頻
 * 本實例通過MediaPlayer播放一首音樂並
 * 通過AudioManager控制手機音頻 
 * */
public class AudioManagerDemo extends Activity {
	Button btnPlay,btnUp,btnDown;
	ToggleButton btnMute;
	AudioManager aManager;
	MediaPlayer mPlayer;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		btnDown=(Button)findViewById(R.id.btnDown);
		btnPlay=(Button)findViewById(R.id.btnPlay);
		btnUp=(Button)findViewById(R.id.btnUp);
		btnMute=(ToggleButton)findViewById(R.id.btnMute);
		//初始化AudioManager
		aManager=(AudioManager) getSystemService(Service.AUDIO_SERVICE);
		OnClickListener listener=new OnClickListener() {			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				switch (v.getId()) {
				case R.id.btnPlay:
					//初始化MediaPlayer為播放音樂做准備
					mPlayer=MediaPlayer.create(
							AudioManagerDemo.this, R.raw.music);
					//設置音樂循環播放
					mPlayer.setLooping(true);
					//播放
					mPlayer.start();
					break;
				case R.id.btnUp:
					//指定調節音樂的音頻為增大，並顯示音量圖形
					aManager.adjustStreamVolume(AudioManager.STREAM_MUSIC,
							AudioManager.ADJUST_RAISE, AudioManager.FLAG_SHOW_UI);
					break;					
				case R.id.btnDown:
					//指定調節音樂的音頻為減小，並顯示音量圖形
					aManager.adjustStreamVolume(AudioManager.STREAM_MUSIC,
							AudioManager.ADJUST_LOWER, AudioManager.FLAG_SHOW_UI);
					break;				
				default:
					break;
				}
			}
		};
		//為按鈕添加監聽器
		btnDown.setOnClickListener(listener);
		btnPlay.setOnClickListener(listener);
		btnUp.setOnClickListener(listener);
		btnMute.setOnCheckedChangeListener(new OnCheckedChangeListener() {			
			@Override
			public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
				// TODO Auto-generated method stub
				//設置音樂靜音
				aManager.setStreamMute(AudioManager.STREAM_MUSIC, isChecked);
			}
		});		
	}
}