同步手机音量键和播放器音量SeekBar

[oyezitan]

最近在做一个同步播放器和手机系统音量的功能，但是遇到一个问题：通过手机音量键调节音量时，按住手机音量键不放，系统音量条游标会波动，严重影响用户体验，苦苦查找，一直找不到原因所在，望大神指点。

package com.orietech.seekbardemo;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.media.AudioManager;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;

/**
 * @Copyright (c) 2011-2012 ORIETech
 * @Class Name：MainActivity
 * @Describe：
 * @Author：Jason Zhang
 * @Modifier:Jason Zhang
 * @version:V1.0
 * 
 */
public class MainActivity extends Activity {
	private AudioManager audiomanage;
	private SeekBar seekBar;
	//是否在滑动中  true 是滑动中
	private boolean isScool=false;
	//
	int numCount=0;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		this.setVolumeControlStream(AudioManager.STREAM_MUSIC);
		seekBar = (SeekBar) findViewById(R.id.seekbar);
		audiomanage = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
		int max = audiomanage.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
		seekBar.setMax(max);
		numCount=max;
		int currentVolume = audiomanage
				.getStreamVolume(AudioManager.STREAM_MUSIC); // 获取当前值
		seekBar.setProgress(currentVolume);
		Log.e(MainActivity.class.getName(), "max=" + max + "---currentVolume="
				+ currentVolume);
		seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() // 调音监听器
		{
			public void onProgressChanged(SeekBar arg0, int progress,
					boolean fromUser) {
				audiomanage.setStreamVolume(AudioManager.STREAM_MUSIC,
						progress, AudioManager.FLAG_SHOW_UI);
				// int currentVolume = audiomanage
				// .getStreamVolume(AudioManager.STREAM_MUSIC); // 获取当前值
				// seekBar.setProgress(currentVolume);
				 Log.e(MainActivity.class.getName(),  "---progress=" + progress);
			}

			@Override
			public void onStartTrackingTouch(SeekBar seekBar) {
				// TODO Auto-generated method stub
				isScool=true;
			}

			@Override
			public void onStopTrackingTouch(SeekBar seekBar) {
				// TODO Auto-generated method stub
				isScool=false;
			}
		});
		IntentFilter filter = new IntentFilter(
				"android.media.VOLUME_CHANGED_ACTION");
		registerReceiver(receiver, filter);
	}

	@Override
	protected void onDestroy() {
		// TODO Auto-generated method stub
		super.onDestroy();
		unregisterReceiver(receiver);
	}

	@Override
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		int currentVolume = audiomanage
				.getStreamVolume(AudioManager.STREAM_MUSIC); // 获取当前值
		Log.e(MainActivity.class.getName(), "onKeyDown currentVolume="
				+ currentVolume);
		if (keyCode == KeyEvent.KEYCODE_VOLUME_UP) {
			if (event.getRepeatCount() == 0) {
				if (currentVolume < numCount) {
					currentVolume = currentVolume + 1;
				}
				audiomanage.adjustStreamVolume(AudioManager.STREAM_MUSIC,
						AudioManager.ADJUST_RAISE, AudioManager.FLAG_SHOW_UI);
				seekBar.setProgress(currentVolume);
				
			}
			return true;

		} else if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
			if (event.getRepeatCount() == 0) {
				if (currentVolume > 0) {
					currentVolume = currentVolume - 1;
				}
				audiomanage.adjustStreamVolume(AudioManager.STREAM_MUSIC,
						AudioManager.ADJUST_LOWER, AudioManager.FLAG_SHOW_UI);
				seekBar.setProgress(currentVolume);
				
			}
			return true;

		}
		return super.onKeyDown(keyCode, event);
	}

	 /*@Override  
	    public boolean dispatchKeyEvent(KeyEvent event) {  
		 int currentVolume = audiomanage
					.getStreamVolume(AudioManager.STREAM_MUSIC); // 获取当前值
	        int action = event.getAction();  
	   
	        if (action ==KeyEvent.ACTION_DOWN) {  
	        	if (currentVolume > 0) {
					currentVolume = currentVolume - 1;
				}
				audiomanage.adjustStreamVolume(AudioManager.STREAM_MUSIC,
						AudioManager.ADJUST_LOWER, AudioManager.FLAG_SHOW_UI);
				seekBar.setProgress(currentVolume);
	            return true;  
	        }  
	   
	        if (action== KeyEvent.ACTION_UP) {  
	        	if (currentVolume < numCount) {
					currentVolume = currentVolume + 1;
				}
				audiomanage.adjustStreamVolume(AudioManager.STREAM_MUSIC,
						AudioManager.ADJUST_RAISE, AudioManager.FLAG_SHOW_UI);
				seekBar.setProgress(currentVolume);
	            return true;  
	        }  
	   
	        return super.dispatchKeyEvent(event);  
	    }  
	   */

	 
	private BroadcastReceiver receiver = new BroadcastReceiver() {

		@Override
		public void onReceive(Context context, Intent intent) {
			if ("android.media.VOLUME_CHANGED_ACTION"
					.equals(intent.getAction())&&!isScool) {

				int type = intent.getIntExtra(
						"android.media.EXTRA_VOLUME_STREAM_TYPE", 0);
				int index = intent.getIntExtra(
						"android.media.EXTRA_VOLUME_STREAM_VALUE", 0);
				int oldIndex = intent.getIntExtra(
						"android.media.EXTRA_PREV_VOLUME_STREAM_VALUE", 0);
				seekBar.setProgress(index);
				Log.e(MainActivity.class.getName(), "type=" + type
						+ "   index=" + index + "    oldIndex=" + oldIndex);
				//android.media.VOLUME_CHANGED_ACTION
				//Intent intent = new Intent(AudioManager.VOLUME_CHANGED_ACTION);
				// android.media.EXTRA_VOLUME_STREAM_TYPE
				// intent.putExtra(AudioManager.EXTRA_VOLUME_STREAM_TYPE,
				// streamType);
				// android.media.EXTRA_VOLUME_STREAM_VALUE
				// intent.putExtra(AudioManager.EXTRA_VOLUME_STREAM_VALUE,
				// index);
				// android.media.EXTRA_PREV_VOLUME_STREAM_VALUE
				// intent.putExtra(AudioManager.EXTRA_PREV_VOLUME_STREAM_VALUE,
				// oldIndex);
			}

		}
	};
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	android:orientation="vertical" >
	<SeekBar
		xmlns:android="http://schemas.android.com/apk/res/android"
		android:id="@+id/seekbar"
		android:layout_width="fill_parent"
		android:layout_height="wrap_content" >
	</SeekBar>
	<VideoView
		android:id="@+id/video"
		android:layout_width="fill_parent"
		android:layout_height="fill_parent"
		android:background="#FF0000" />
</LinearLayout>

[oyezitan]

拖动进度条快速滑动，手机音量进度条也会乱跳。

[LYambition]

请问博主能否给本小白解释一下这个程序的工作原理和如何使用SeekBar来获取到系统音量？感激不尽