Android 播放音频详解手机开发

package com.example.test2; 
 
import android.media.AudioManager; 
import android.media.MediaPlayer; 
import android.os.Bundle; 
import android.app.Activity; 
import android.app.Service; 
import android.view.Menu; 
import android.view.View; 
import android.widget.Button; 
import android.widget.CompoundButton; 
import android.widget.CompoundButton.OnCheckedChangeListener; 
import android.widget.ToggleButton; 
 
public class MainActivity extends Activity { 
 
    private Button btnPlay=null, btnUpper=null, btnLower=null; 
    private ToggleButton tbMute=null; 
    private MediaPlayer mediaPlayer=null; //声频 
    private AudioManager audioManager=null; //音频 
     
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.activity_main); 
     
        audioManager=(AudioManager)getSystemService(Service.AUDIO_SERVICE); 
        btnPlay=(Button)findViewById(R.id.btnPlay); 
        btnUpper=(Button)findViewById(R.id.btnUpper); 
        btnLower=(Button)findViewById(R.id.btnLower); 
        btnPlay.setOnClickListener(listener); 
        btnUpper.setOnClickListener(listener); 
        btnLower.setOnClickListener(listener); 
        tbMute=(ToggleButton)findViewById(R.id.tbMute); 
        tbMute.setOnCheckedChangeListener(new OnCheckedChangeListener(){ 
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { 
                audioManager.setStreamMute(AudioManager.STREAM_MUSIC, !isChecked); //设置是否静音 
            } 
        }); 
    } 
     
    View.OnClickListener listener=new View.OnClickListener(){ 
        public void onClick(View v) { 
            @SuppressWarnings("unused") 
            Button btn=(Button)v; 
            switch (v.getId()) { 
            case R.id.btnPlay://播放音乐 
                mediaPlayer=MediaPlayer.create(MainActivity.this, R.raw.music); 
                mediaPlayer.setLooping(true);//设置循环播放 
                mediaPlayer.start();//播放声音     
                break; 
            case R.id.btnUpper://增多音量 
                //adjustStreamVolume: 调整指定声音类型的音量 
                audioManager.adjustStreamVolume(AudioManager.STREAM_MUSIC,  
                        AudioManager.ADJUST_RAISE,  
                        AudioManager.FLAG_SHOW_UI);    //调高声音 
                break; 
            case R.id.btnLower://减少音量 
                //第一个参数：声音类型 
                //第二个参数：调整音量的方向 
                //第三个参数：可选的标志位 
                audioManager.adjustStreamVolume(AudioManager.STREAM_MUSIC,  
                        AudioManager.ADJUST_LOWER,  
                        AudioManager.FLAG_SHOW_UI);//调低声音 
                break; 
            } 
        } 
    }; 
 
}

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" android:layout_width="fill_parent" 
    android:layout_height="fill_parent"> 
    <Button android:id="@+id/btnPlay"  
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content"  
        android:text="播放音乐" /> 
    <LinearLayout android:orientation="horizontal" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:layout_gravity="center_horizontal"> 
        <ToggleButton android:id="@+id/tbMute" 
            android:layout_width="fill_parent" 
            android:layout_height="wrap_content"  
            android:textOn="静音" 
            android:textOff="正常" 
            android:checked="true" 
            android:layout_gravity="center_vertical" /> 
        <Button android:id="@+id/btnUpper" 
            android:text="增大音量"  
            android:layout_width="wrap_content" 
            android:layout_height="wrap_content" /> 
        <Button android:id="@+id/btnLower" 
            android:text="减小音量"  
            android:layout_width="wrap_content" 
            android:layout_height="wrap_content" /> 
    </LinearLayout> 
</LinearLayout>