我正在尝试制作一款简单的 2D Android 游戏。在这个游戏中，我试图制作一些按钮来控制角色，而角色显示在 SurfaceView 中。目前，SurfaceView 仅呈现黑屏。
这是我的 MainActivity，它扩展了 Activity:
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
GameView gm = (GameView)findViewById(R.id.snake_surface);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.layout.main, menu);
return true;
}
GameView 类，它扩展了 SurfaceView:
private HeroSprite hero;
public GameView(Context context, AttributeSet attributeSet) {
super(context, attributeSet);
gameLoopThread = new GameLoopThread(this);
getHolder().addCallback(new SurfaceHolder.Callback() {
public void surfaceDestroyed(SurfaceHolder holder) {
boolean retry = true;
gameLoopThread.setRunning(false);
while (retry) {
try {
gameLoopThread.join();
retry = false;
} catch (InterruptedException e) {}
}
}
public void surfaceCreated(SurfaceHolder holder) {
createSprites();
createHero();
gameLoopThread.setRunning(true);
gameLoopThread.start();
}
public void surfaceChanged(SurfaceHolder holder, int format,int width, int height) {
}
});
bmpBlood = BitmapFactory.decodeResource(context.getResources(), R.drawable.blood1);
}
private void createHero(){
hero=(createHeroSprite(R.drawable.aslan));
}
private HeroSprite createHeroSprite(int resouce) {
Bitmap bmp = BitmapFactory.decodeResource(getResources(), resouce);
return new HeroSprite(this, bmp);
}
private void createSprites() {
sprites.add(createSprite(R.drawable.tavsan));
sprites.add(createSprite(R.drawable.fare));
sprites.add(createSprite(R.drawable.sansar));
sprites.add(createSprite(R.drawable.tavsan));
sprites.add(createSprite(R.drawable.fare));
sprites.add(createSprite(R.drawable.sansar));
sprites.add(createSprite(R.drawable.tavsan));
sprites.add(createSprite(R.drawable.fare));
sprites.add(createSprite(R.drawable.sansar));
sprites.add(createSprite(R.drawable.tavsan));
sprites.add(createSprite(R.drawable.tavsan));
}
private Sprite createSprite(int resouce) {
Bitmap bmp = BitmapFactory.decodeResource(getResources(), resouce);
return new Sprite(this, bmp);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.GREEN);
for (int i = temps.size() - 1; i >= 0; i--) {
temps.get(i).onDraw(canvas);
}
for (Sprite sprite : sprites) {
sprite.onDraw(canvas);
}
hero.onDraw(canvas);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (System.currentTimeMillis() - lastClick > 300) {
lastClick = System.currentTimeMillis();
float x = event.getX();
float y = event.getY();
synchronized (getHolder()) {
for (int i = sprites.size() - 1; i >= 0; i--) {
Sprite sprite = sprites.get(i);
if ((sprite).isCollition(x, y)) {
sprites.remove(sprite);
temps.add(new TempSprite(temps, this, x, y, bmpBlood));
break;
}
}
}
}
return true;
}
我的 GameLoopThread 类，它扩展了 Thread
static final long FPS = 10;
private GameView view;
private boolean running = false;
public GameLoopThread(GameView view) {
this.view = view;
}
public void setRunning(boolean run) {
running = run;
}
@Override
public void run() {
long ticksPS = 1000 / FPS;
long startTime;
long sleepTime;
while (running) {
Canvas c = null;
startTime = System.currentTimeMillis();
try {
c = view.getHolder().lockCanvas();
synchronized (view.getHolder()) {
view.onDraw(c);
}
} finally {
if (c != null) {
view.getHolder().unlockCanvasAndPost(c);
}
}
sleepTime = ticksPS - (System.currentTimeMillis() - startTime);
try {
if (sleepTime > 0)
sleep(sleepTime);
else
sleep(10);
} catch (Exception e) {
}
}
}
这是我的布局:
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="30dp"
android:gravity="center"
android:orientation="horizontal" >
<TextView
android:id="@+id/score"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical|center_horizontal"
android:text="Score:"
android:textSize="20dp" />
<Button
android:id="@+id/btnThread"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical|center_horizontal" />
<TextView
android:id="@+id/max"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical|center_horizontal"
android:layout_marginLeft="100dp"
android:text="Max:"
android:textSize="20dp" />
</LinearLayout>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="0.3" >
<SurfaceView
android:id="@+id/snake_surface"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="0.3" />
</FrameLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:weightSum="1" >
<Button
android:id="@+id/butUp"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|center"
android:text="UP" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<Button
android:id="@+id/butLeft"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="LEFT" />
<Button
android:id="@+id/butRight"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="RIGHT" />
</RelativeLayout>
<Button
android:id="@+id/butDown"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|center"
android:text="DOWN" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
最佳答案
您在布局中的 View 是 SurfaceView，而不是 GameView。你需要改变它:
<your.package.name.GameView
android:id="@+id/snake_surface"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="0.3" />
并将 your.package.name 替换为包含 GameView 的包的实际名称。
另外，GameView gm = ... 行需要在 setContentView 之后。
最后，别忘了调用 gm.invalidate()当您修改了将要绘制的项目时!
关于Android SurfaceView 为空，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13733760/