背景图像未显示在surfaceholder中

Question

我试图显示背景移动图像并移动2d线图像和球图像，但它没有显示。

这是我的代码：

backGround = BitmapFactory.decodeResource(this.getResources(),
            R.drawable.ab);

    // decrement the far background
            mBGFarMoveX = mBGFarMoveX - 1;

            // decrement the near background
            mBGNearMoveX = mBGNearMoveX - 4;

            // calculate the wrap factor for matching image draw
            int newFarX = backGround.getWidth() - (-mBGFarMoveX);

            // if we have scrolled all the way, reset to start
            if (newFarX <= 0) {
                mBGFarMoveX = 0;
                // only need one draw
                c.drawBitmap(backGround, mBGFarMoveX, 0, null);

            } else {
                // need to draw original and wrap
                c.drawBitmap(backGround, mBGFarMoveX, 0, null);
                c.drawBitmap(backGround, newFarX, 0, null);
            }

除了显示背景图片外，一切都很顺利。 背景显示为黑色，我的程序运行得很慢。