实现游戏音效的预加载

游戏中有很多东西是需要预加载进来的，这样可以使游戏更流畅，虽然，游戏中音效占用的资源比较少，但是，还是有必要为音效做一个预加载的，这里用安卓原生的方法实现了一个音效加载系统。

思路：

安卓中游戏的资源通常都是根据id来加载的（这个id可以在R.java文件中找到），在系统中使用了两个HashMap,一个存储资源的ID，一个存储音效加载后的ID，这两个HashMap有共同的key值将两个表联系起来。

系统中实现了资源的加载，根据资源ID播放音效，卸载资源。

下面是脑图的地址，是系统中详细函数的介绍。

http://naotu.baidu.com/file/079133fa68a2e51d5800f905e77ef67b?token=d52654a7a8883f62

Demo代码：

MainActivity.java

package com.example.soundloadsystem;import android.R.integer;import android.app.Activity;import android.content.Context;import android.media.AudioManager;import android.media.SoundPool;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class MainActivity extends Activity {public static MainActivity _instance ;public SoundLoadSystem soundLoadSystem;public SoundPool m_soundPool ;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);//setContentView(R.layout.activity_main);setContentView(R.layout.main);_instance = this;m_soundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 0);soundLoadSystem = SoundLoadSystem.Instance();addSoundRes();initUICallback();}public void addSoundRes(){soundLoadSystem.add(R.raw.sound_0);soundLoadSystem.add(R.raw.sound_1);soundLoadSystem.add(R.raw.sound_2);soundLoadSystem.add(R.raw.sound_3);soundLoadSystem.add(R.raw.sound_4);soundLoadSystem.add(R.raw.sound_5);}public void initUICallback(){Button btn1 = (Button)findViewById(R.id.Button01);Button btn2 = (Button)findViewById(R.id.Button02);Button btn3 = (Button)findViewById(R.id.Button04);btn1.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubsoundLoadSystem.load();}});btn2.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stub\AudioManager am = (AudioManager)_instance.getSystemService(Context.AUDIO_SERVICE);float streamVolumeCurrent = am.getStreamVolume(AudioManager.STREAM_MUSIC);float streamVolumeMax = am.getStreamMaxVolume(AudioManager.STREAM_MUSIC);float volume = streamVolumeCurrent / streamVolumeMax;m_soundPool.play(soundLoadSystem.getRandomID(), volume, volume, 1, 0, 1.0f);}});btn3.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubsoundLoadSystem.unload();}});}}

SoundLoadSystem.java

package com.example.soundloadsystem;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Random;import android.R.integer;import android.content.Context;import android.drm.DrmStore.RightsStatus;import android.media.AudioManager;import android.media.SoundPool;import android.util.Log;public class SoundLoadSystem {public static SoundLoadSystem _instance ;public HashMap<Integer, Integer> m_soundResIDMap ;public HashMap<Integer, Integer> m_soundIDMap;public int m_index = 0 ;public static SoundLoadSystem Instance(){if (_instance == null) {_instance = new SoundLoadSystem();}return _instance ;}public static void Destory(){_instance = null ;System.gc();}private SoundLoadSystem() {// TODO Auto-generated constructor stubm_soundResIDMap = new HashMap<Integer, Integer>();m_soundIDMap = new HashMap<Integer, Integer>();}public void add(Integer id){if (isHave(id) == false) {m_soundResIDMap.put(m_index, id);m_index++ ;}}public void load(){Context cot = MainActivity._instance ;SoundPool spPool = MainActivity._instance.m_soundPool;int per = 0 ;Iterator iterator = m_soundResIDMap.entrySet().iterator() ;while (iterator.hasNext()) {Map.Entry<Integer,Integer> entry = (Map.Entry<Integer,Integer>)iterator.next();Integer index = entry.getKey();Integer id = entry.getValue();Integer spID = spPool.load(cot, id,1);m_soundIDMap.put(index, spID);per++;}}public int getLength(){//Because m_index start from 0,so the length is m_index + 1.return m_soundIDMap.size();}public boolean isHave(Integer id){return m_soundResIDMap.containsValue(id) ;}public Integer getRandomID(){if (m_soundIDMap.size() == 0|| m_soundResIDMap.size() == 0) {Log.e("load_error","Doesn't load any res.");return -1;}Integer ret = -1;Random random = new Random();Integer randInteger = random.nextInt(getLength());ret = m_soundIDMap.get(randInteger);return ret;}public void unload(){SoundPool spPool = MainActivity._instance.m_soundPool;spPool.unload(1);Iterator iterator = m_soundIDMap.entrySet().iterator() ;while (iterator.hasNext()) {Map.Entry<Integer,Integer> entry = (Map.Entry)iterator.next();Integer id = entry.getValue();spPool.unload(id);}m_soundIDMap.clear();m_soundIDMap = new HashMap<Integer, Integer>();}public int getSoundIDByResID(Integer resID){int soundID = -1;int index = -1;boolean isHave = m_soundResIDMap.containsKey(resID);if (isHave) {Iterator iterator = m_soundIDMap.entrySet().iterator() ;while (iterator.hasNext()) {Map.Entry<Integer,Integer> entry = (Map.Entry)iterator.next();Integer idx = entry.getKey();Integer id = entry.getValue();if (id == resID) {index = idx ;}}soundID = m_soundIDMap.get(index);}else {Log.e("sound_res","can't find sound which id is" + resID);}return soundID ;}public void reset(){m_soundIDMap.clear();m_soundResIDMap.clear();m_soundIDMap = new HashMap<Integer, Integer>();m_soundResIDMap = new HashMap<Integer, Integer>();m_index = 0;}}

Demo下载地址：http://download.csdn.net/detail/c_boy_lu/9300661