创建viewcontroller
let oneNav = UINavigationController(rootViewController: firViewController())
oneNav.tabBarItem = UITabBarItem(title: “首页”, image: UIImage(named: “”), selectedImage: UIImage(named: “”))
let TwoNav = UINavigationController(rootViewController: secViewController())
TwoNav.tabBarItem = UITabBarItem(title: “我听”, image: UIImage(named: “”), selectedImage: UIImage(named: “”))
let ThreeNav = UINavigationController(rootViewController: tirViewController())
ThreeNav.tabBarItem = UITabBarItem(title: “播放”, image: UIImage(named: “”), selectedImage: UIImage(named: “”))
let tav = UITabBarController()
tav.viewControllers = [oneNav,TwoNav,ThreeNav]
tav.selectedViewController = TwoNav
self.window?.rootViewController = tav