import UIKit

class MainTabBarViewController: UITabBarController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 1.初始化所有的子控制器
        setUpChildViewController()
    }
}

// MARK: - setUpChildViewController
extension MainTabBarViewController {
    fileprivate func setUpChildViewController() {
        
        let homeVC = TabBar1ViewController()
        setUpNavRootViewControllers(vc: homeVC, title: "首页", image: "home_icon", selImage: "home_icon1")
        
        let musicVC = TabBar2ViewController()
        setUpNavRootViewControllers(vc: musicVC, title: "音乐", image: "yuershi_icon", selImage: "yuershi_icon1")
        
        let discoverVC = TabBar3ViewController()
        setUpNavRootViewControllers(vc: discoverVC, title: "发现", image: "kefu_icon", selImage: "kefu_icon1")
        
        let mineVC = TabBar4ViewController()
        setUpNavRootViewControllers(vc: mineVC, title: "我的", image: "wode_icon", selImage: "wode_icon1")
    }
    
    // 初始化一个到导航控制器的控制器
    fileprivate func setUpNavRootViewControllers(vc: UIViewController, title:String, image: String, selImage: String) {
        vc.title = title
        vc.tabBarItem.selectedImage = UIImage(named: selImage)!.withRenderingMode(.alwaysOriginal)
        vc.tabBarItem.image = UIImage(named: image)!.withRenderingMode(.alwaysOriginal)
        vc.tabBarItem.setTitleTextAttributes(NSDictionary(object:UIColor (colorLiteralRed: 51/255.0, green: 51/255.0, blue: 51/255.0, alpha: 1), forKey:NSForegroundColorAttributeName as NSCopying) as? [String : AnyObject], for:UIControlState.normal);
        vc.tabBarItem.setTitleTextAttributes(NSDictionary(object:UIColor.red, forKey:NSForegroundColorAttributeName as NSCopying) as? [String : AnyObject], for:UIControlState.selected)

//      tabbar 背景颜色
//        UITabBar.appearance().tintColor=UIColor.white
//        UITabBar.appearance().isTranslucent=false
//        这里用了一个自定义的  NavigationController
        self.addChildViewController(BaseNavigationController(rootViewController: vc))
    }
}

如有问题欢迎指正，谢谢。