两部分代码比较，所带来的问题，下面已解决

// position the label on the center of the screen
//	bg->setPosition(Vec2(origin.x + visibleSize.width / 2,
	//	origin.y + visibleSize.height / 2));
//	this->addChild(bg);
	<span style="color:#ff0000;">auto bg = Sprite::create("background.png");
	bg->setPosition(Vec2(visibleSize.width / 2, visibleSize.height / 2));</span>
<span style="color:#ff0000;background-color: rgb(204, 204, 204);">	this->addChild(bg);</span>

能正常显示！！