我想添加效果我的指针。如何在触摸区域添加效果或动画？

Question

我想为指针添加效果。也就是说，当我在屏幕上滚动手指时，显示效果或动画，其周围显示触摸区域。怎么加？

Answer 1

我发现了这个：

public class TestActivity extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new DrawingView(this));
}

class DrawingView extends SurfaceView {

    private final SurfaceHolder surfaceHolder;
    private final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);

    public DrawingView(Context context) {
        super(context);
        surfaceHolder = getHolder();
        paint.setColor(Color.RED);
        paint.setStyle(Style.FILL);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if(event.getAction() == MotionEvent.ACTION_DOWN) {
            if (surfaceHolder.getSurface().isValid()) {
                Canvas canvas = surfaceHolder.lockCanvas();
                canvas.drawColor(Color.BLACK);
                canvas.drawCircle(event.getX(), event.getY(), 50, paint);
                surfaceHolder.unlockCanvasAndPost(canvas);
            }
        }
        return false;
    }

}

}