iOS UITabBarItem 修改图片颜色

if self.tabBar.items != nil {
    let classNameArr = ["Home","Recording","Tools","Mine"]
    for item in self.tabBar.items! {
        let clsName = classNameArr[item.tag]
        let lowStr = clsName.lowercased()
        let color = kSkinDark ? nil : UIColor(hexString: "9B9AA1")
        let image = UIImage(named: "tabbar_icon_" + lowStr + "_normal")?.imageWithTintColor(tintColor: color)
        item.image = image
    }
}