Android 自定义SeekBar动态改变硬件音量大小实现和音量键的同步(推荐)

package com.hero.zhaoq.seekbarchangeddemo;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.ContentObserver;
import android.media.AudioManager;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.SeekBar;
/**
 * Android实现 SeekBar更新音量 并实现 和硬件同步
 */
public class MainActivity extends AppCompatActivity {
 private SeekBar seekbar_video;
 private ContentObserver mVoiceObserver;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);//获取媒体系统服务
  seekbar_video= (SeekBar) findViewById(R.id.seekbar_video);//注册ID
  seekbar_video.setMax(15);//设置最大音量
  seekbar_video.setProgress(audioManager.getStreamVolume(AudioManager.STREAM_MUSIC));// 当前的媒体音量
  myRegisterReceiver();//注册同步更新的广播
  Log.i("lyj_ring", "mVoiceSeekBar max voluem = "+audioManager.getStreamMaxVolume(AudioManager.STREAM_SYSTEM));
  seekbar_video.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
   public void onStopTrackingTouch(SeekBar arg0) {
   }
   public void onStartTrackingTouch(SeekBar arg0) {
   }
   public void onProgressChanged(SeekBar arg0, int arg1, boolean arg2) {
    AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
    Log.v("lyj_ring", "mVoiceSeekBar max progress = "+arg1);
    //系统音量和媒体音量同时更新
    audioManager.setStreamVolume(AudioManager.STREAM_SYSTEM, arg1, 0);
    audioManager.setStreamVolume(3, arg1, 0);// 3 代表 AudioManager.STREAM_MUSIC
   }
  });
  mVoiceObserver = new ContentObserver(new Handler()) {
   @Override
   public void onChange(boolean selfChange) {
    super.onChange(selfChange);
    AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
    seekbar_video.setProgress(audioManager.getStreamVolume(AudioManager.STREAM_SYSTEM));
    //或者你也可以用媒体音量来监听改变，效果都是一样的。
    //mVoiceSeekBar.setProgress(audioManager.getStreamVolume(AudioManager.STREAM_MUSIC));
   }
  };
 }
 private void myRegisterReceiver(){
  MyVolumeReceiver mVolumeReceiver = new MyVolumeReceiver() ;
  IntentFilter filter = new IntentFilter() ;
  filter.addAction("android.media.VOLUME_CHANGED_ACTION") ;
  registerReceiver(mVolumeReceiver, filter) ;
 }
 /**
  * 处理音量变化时的界面显示
  * @author long
  */
 private class MyVolumeReceiver extends BroadcastReceiver {
  @Override
  public void onReceive(Context context, Intent intent) {
   //如果音量发生变化则更改seekbar的位置
   if(intent.getAction().equals("android.media.VOLUME_CHANGED_ACTION")){
    AudioManager mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
    int currVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC) ;// 当前的媒体音量
    seekbar_video.setProgress(currVolume) ;
   }
  }
 }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:id="@+id/ringtone_seekbar_parent"
 android:layout_width="match_parent"
 android:layout_height="160px"
 android:layout_marginTop="0dip"
 android:layout_weight="1"
 android:gravity="center_vertical"
 android:orientation="horizontal" >
 <SeekBar
  android:id="@+id/seekbar_video"
  android:layout_width="match_parent"
  android:layout_height="25dp"
  android:max="0"
  android:progress="0"
  android:progressDrawable="@drawable/seekbar_progress_layer_list"
  android:thumb="@mipmap/play_seekbar_icon"
  android:layout_weight="18"/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<layer-list
 xmlns:android="http://schemas.android.com/apk/res/android">
 <!--未选中 状态-->
 <item android:id="@android:id/background"
  android:drawable="@mipmap/volumn_bg" />
 <!--<!–选中状态–>-->
 <item android:id="@android:id/progress">
  <scale android:drawable="@mipmap/volumn_primary" android:scaleWidth="100%" />
 </item>
</layer-list>