java - 我正在构建一个汽车游戏我想通过 keyevent 移动汽车，算法没问题，但汽车不动

Question

主类是:

public class test extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new Game(this,null));
}

Game类是view类的扩展，可以让我们画小车并设置位置，我调用了onkey方法来控制小车的方向和角度

public class Game extends View {
private Paint paint= new Paint();
float x,y;
float speed = 5,angle = 0,mod = 0;
Bitmap car;
Boolean b=false;
public Game(Context context, AttributeSet attrs) {
    super(context, attrs);
    try { // here I call the car image as a bitmap object
        AssetManager assetManager=context.getAssets();
        InputStream inputStream= assetManager.open("car.png");
        BitmapFactory.Options options=new BitmapFactory.Options();
        options.inPreferredConfig = Bitmap.Config.ARGB_4444;
        car=BitmapFactory.decodeStream(inputStream,null,options);
        inputStream.close();
        Log.d("Bitmap Text", "bobrgb888.png format: "+car.getConfig());
    } catch (Exception e) {
    // TODO: handle exception
    }
 }

       @Override
       protected void   onDraw(Canvas canvas) {
       x += (speed*mod) * Math.cos(Math.PI/180 * angle);
           y += (speed*mod) * Math.sin(Math.PI/180 * angle);
       canvas.rotate((float) (Math.PI/180 * angle));
       canvas.drawBitmap(car,-(car.getWidth()/2), -(car.getHeight()/2), null);
       canvas.restore();
      }
          public boolean onKey(View view, int keyCode, KeyEvent event) {
        switch (event.getAction()) {
        case KeyEvent.ACTION_DOWN:              
            break;
        case KeyEvent.ACTION_UP:
            {if(event.getKeyCode() == KeyEvent.KEYCODE_A ||               event.getKeyCode() == KeyEvent.KEYCODE_B)
            {
                this.mod = 0;
            }}
            break;

        case KeyEvent.ACTION_MULTIPLE:{
            if(event.getKeyCode() == KeyEvent.KEYCODE_A)
            {
                mod = 1;
            }
            if(event.getKeyCode() == KeyEvent.KEYCODE_B)
            {
                mod = -1;
            }
            if(event.getKeyCode() == KeyEvent.KEYCODE_C)
            {
                angle -= 5;
            }

            if(event.getKeyCode() == KeyEvent.KEYCODE_D)
            {
                angle+=5;
            }
            }
            break;
        }
        invalidate();
        return event.getKeyCode() != KeyEvent.KEYCODE_BACK;
    }
}

我设置下一个点的 x 和 y我按照选择的角度旋转图像我在当前位置画车。当 A 或 B 键向上时，汽车停止长按按键(A、B、C、D)时，角度和方向发生变化。

Answer 1

使用这个:

@Override
    public boolean onKeyDown(View view, Editable arg1, int keyCode, KeyEvent event) {

而不是这个:

public boolean onKey(View view, int keyCode, KeyEvent event) {