可能有两个问题，一个是关于Handler，另一个是关于声音池。
这是错误日志:
09-09 06:36:24.743: W/dalvikvm(541): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
09-09 06:36:24.801: E/AndroidRuntime(541): FATAL EXCEPTION: main
09-09 06:36:24.801: E/AndroidRuntime(541): java.lang.NullPointerException
09-09 06:36:24.801: E/AndroidRuntime(541): at com.example.helloandroid.WelcomeView.playSound(WelcomeView.java:78)
09-09 06:36:24.801: E/AndroidRuntime(541): at com.example.helloandroid.TestHelloAndroidActivity$1.handleMessage(TestHelloAndroidActivity.java:67)
09-09 06:36:24.801: E/AndroidRuntime(541): at android.os.Handler.dispatchMessage(Handler.java:99)
09-09 06:36:24.801: E/AndroidRuntime(541): at android.os.Looper.loop(Looper.java:137)
09-09 06:36:24.801: E/AndroidRuntime(541): at android.app.ActivityThread.main(ActivityThread.java:4424)
09-09 06:36:24.801: E/AndroidRuntime(541): at java.lang.reflect.Method.invokeNative(Native Method)
09-09 06:36:24.801: E/AndroidRuntime(541): at java.lang.reflect.Method.invoke(Method.java:511)
09-09 06:36:24.801: E/AndroidRuntime(541): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
09-09 06:36:24.801: E/AndroidRuntime(541): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
09-09 06:36:24.801: E/AndroidRuntime(541): at dalvik.system.NativeStart.main(Native Method)
谁能帮忙!非常感谢。
这是我的代码，请忽略注释中的中文字符。非常感谢。 :P
1.“TestAndroidActivity”代码:
package com.example.helloandroid;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.os.Looper;
import android.os.Message;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.Window;
import android.view.WindowManager;
public class TestHelloAndroidActivity extends Activity {
/** Called when the activity is first created. */ <br/>
View CurrentView;
WelcomeView wv;
ProgressView pv;
GameView gv;
boolean wantSound=true; //是否开启声音,默认不开
Handler myHandler = new Handler(){ //创建自定义的Handler
public void handleMessage(Message msg) { //重写处理消息的方法
switch(msg.what){ //判断Message对象的类型
case 0: //切换到开始游戏前的进度条界面
pv = new ProgressView(TestHelloAndroidActivity.this, 4); //target为0，进度条走完后去Gameview
setContentView(pv); //切换屏幕到ProgressView
CurrentView = pv; //记录当前View
wv.soundPool.release(); //释放SoundPool
wv.soundPool = null; //声明SoundPool对象为null
wv = null; //声明WelcomeView对象为null
new Thread(){ //创建并启动一个新线程
public void run(){
Looper.prepare();
BitmapManager.loadGamePublic(getResources()); //加载游戏界面图片资源
updateProgress(40); //更新进度条
gv = new GameView(null); //创建GameView对象
updateProgress(100); //更新进度条
}
}.start();
break;
case 4: //开始游戏
setContentView(gv); //切换屏幕到GameView
CurrentView = gv; //记录当前View
pv = null; //声明pv指向的ProgressView的
break;
/*case 1: //显示帮助
hv = new HelpView(RunActivity.this); //创建HelpView对象
setContentView(hv); //切换屏幕到HelpView
currentView = hv; //记录当前View
wv.resetMenu(); //重置菜单按钮
break; */
case 2: //退出游戏
wv.stopSound(1); //停止声音的播放
wv.soundPool.release(); //释放WelcomeView的SoundPool对象
android.os.Process.killProcess(android.os.Process.myPid());
System.exit(0); //退出程序
break;
case 3: //显示欢迎界面
setContentView(wv); //设置当前屏幕为WelcomeView对象
CurrentView = wv; //记录当前View
if(wantSound){ //如有需要，播放声音
wv.playSound(1, -1);
}
pv = null; //将pv指向的ProgressView声明为垃圾
break;
}
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//设置全屏
getWindow().requestFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
BitmapManager.loadSystemPublic(getResources());
pv = new ProgressView(this, 3); //创建一个ProgressView对象，目标为3，即走满后去WelcomeView
setContentView(pv);
CurrentView = pv;
new Thread(){
public void run(){
Looper.prepare();
BitmapManager.loadWelcomePublic(getResources()); //加载欢迎界面的图片资源
updateProgress(60);
wv = new WelcomeView(TestHelloAndroidActivity.this);//初始化WelcomeView
updateProgress(100);
}
}.start();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if(event.getAction() == MotionEvent.ACTION_UP){
int x = (int)event.getX(); //获取屏幕点击处的X坐标
int y = (int)event.getY(); //获取屏幕点击处的Y坐标
if(CurrentView == wv){ //如果当前View为WelcomeView
return wv.myTouchEvent(x, y); //调用WelcomeView的相关事件处理方法
}
/*else if(CurrentView == gv){ //如果当前View为GameView
return gv.myTouchEvent(x, y); //调用GameView的相关事件处理方法
} */
}
return true;
}
//方法：更新进度条 <br/>
public void updateProgress(int progress){
if(pv != null){
pv.setProgress(progress);
}
}
}
2. WelcomeView:
package com.example.helloandroid;
import java.util.HashMap;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.media.AudioManager;
import android.media.SoundPool;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class WelcomeView extends SurfaceView implements SurfaceHolder.Callback {
TestHelloAndroidActivity father;
WelcomeDrawThread wdt;
int status = -1; //记录当前状态,0：背景渐显，1：美女移入，2：显示菜单，3：待命，4：有按钮点下
int selectedIndex=-1;//选择的菜单选项，如0为开始游戏/1为帮助/2退出
int mm_x = 129; //mm图片宽度
int mm_y = 289; //mm图片高度
int mmX; //终点X坐标0
int mmY; //终点Y左边191
int btnIndex = 0; //按钮帧索引
int btnSpan = 10; //按钮间隔
int btnHight = 25; //按钮高度
int alpha = 0;
Rect rectMenuStart = new Rect(105,334,317,359);//开始按钮矩形框
Rect rectMenuHelp = new Rect(105,369,317,394);//帮助按钮矩形框
Rect rectMenuQuit = new Rect(105,404,317,429);//退出按钮矩形框
Rect rectSoundMenu = new Rect(140,440,172,472);//声音按钮
SoundPool soundPool; //SoundPool对象引用
HashMap<Integer,Integer> SoundMap; //存放声音资源的Map
public WelcomeView(TestHelloAndroidActivity father) {
super(father);
this.father = father;
getHolder().addCallback(this);
wdt = new WelcomeDrawThread(this, getHolder());
}
public void doDraw(Canvas canvas){
Paint paint = new Paint(); //创建画笔
paint.setAlpha(alpha);
BitmapManager.drawWelcomePublic(0, canvas, 0, 0,paint);//画背景
switch(status){
case 1://状态：美女渐入
BitmapManager.drawWelcomePublic(1, canvas, mmX, mmY, paint);
case 4://状态：有按钮点下
case 3://状态：待命状态，等待按钮按下
BitmapManager.drawWelcomePublic((father.wantSound?6:5), canvas, 140, 440, paint);//画声音菜单，5表示开启那帧，6表示关闭那帧
case 2://状态：显示菜单按钮, 光画框还没写字呢09.09
paint.setAlpha(alpha); //设置画笔透明度
for(int i=0; i<3; i++){
BitmapManager.drawWelcomePublic((i==selectedIndex?btnIndex+2:2), canvas, rectMenuStart.left, rectMenuStart.top+i*(btnHight + btnSpan), paint);
}
break;
}
}
//方法：初始化声音
public void initSound(TestHelloAndroidActivity father){
soundPool = new SoundPool(1,AudioManager.STREAM_MUSIC,100);
int id = soundPool.load(father, R.raw.welcom_background, 1);
SoundMap.put(1, id); //加载背景音乐
}
//方法：播放声音
public void playSound(int sound,int loop){
AudioManager am = (AudioManager)getContext().getSystemService(Context.AUDIO_SERVICE);
float streamVolumeCurrent = am.getStreamVolume(AudioManager.STREAM_MUSIC);
float streamVolumeMax = am.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
float volume = streamVolumeCurrent / streamVolumeMax;
soundPool.play(SoundMap.get(sound), volume, volume, 1, loop, 1);
}
//方法：停止声音
public void stopSound(int sound){
soundPool.stop(SoundMap.get(sound));
}
//方法：处理用户点击屏幕事件
public boolean myTouchEvent(int x,int y){
if(rectMenuStart.contains(x, y)){//点下开始按钮
selectedIndex = 0;//设置按下的索引
status = 4;//设置状态为4，即按下列按钮
}
else if(rectMenuHelp.contains(x, y)){//点下帮助按钮
selectedIndex = 1;//设置按下的索引
status = 4;//设置状态为4，即按下列按钮
}
else if(rectMenuQuit.contains(x, y)){//点下退出按钮
selectedIndex = 2;//设置按下的索引
status = 4;//设置状态为4，即按下列按钮
}
else if(rectSoundMenu.contains(x, y)){//点下了声音菜单按钮
if(father.wantSound){//按下之前是有声音的
stopSound(1);//停止声音的播放
}
else{//按下之前没声音
playSound(1, -1);
}
father.wantSound = !father.wantSound;//置反
}
return true;
}
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
}
最佳答案
您不会在 Activity 中的WelcomeView中调用initSound，因此执行soundPool时null仍然是playSound。