swift 练习小demo 自定义UITabBarController navBar VC 简单框架

AppDelegate.swift
import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
let  tabBarController = MianTabBarController()

window?.rootViewController = tabBarController
return true
}
MianTabBarController.swift
import UIKit

class MianTabBarController: UITabBarController {

override func viewDidLoad() {
super.viewDidLoad()
self.selectedIndex = 0
setupItem()

}

private func setupItem (){
let firstVC = ViewController( )
firstVC.title = "1"
setupChildVC(vc: firstVC, title: "首页", image: "tab-bar_icon_empty-main24", selectedImage: "tab bar_icon_main24")

let secondVC = UIViewController()
secondVC.title = "2"

secondVC.view.backgroundColor = .green
setupChildVC(vc: secondVC, title: "消息", image: "tab-bar_icon_empty-message24", selectedImage: "tab-bar_icon_message24")

let forthVC = UIViewController()
forthVC.title = "3"

forthVC.view.backgroundColor = .brown
setupChildVC(vc: forthVC, title: "我的", image: "tab-bar_icon_mine24", selectedImage: "tab-bar_icon_main24")

}
private func setupChildVC(vc:UIViewController,title:String,image:String,selectedImage:String){

let nav = UINavigationController(rootViewController: vc)

addChildViewController(nav)

nav .tabBarItem.title = title;

nav.tabBarItem.image = UIImage(named: image)

nav.tabBarItem.selectedImage = UIImage(named: selectedImage)

}

}