//设置tabBarItem的title，以及点击和不点击状态图片
self.tabBarController.tabBarItem = UITabBarItem(title: "投资理财", image: image, selectedImage: imageSeleted);
 
//设置tabBarItem的title的字体颜色和字大小及字体样式 
self.tabBarController.tabBarItem.setTitleTextAttributes([NSForegroundColorAttributeName:BGColor,NSFontAttributeName:UIFont(name: "Helvetica-Bold", size: 12)!], forState: UIControlState.Normal)

12)!], forState: UIControlState.Selected)