Storyboardを使わずにコードだけで画面を生成、遷移をする

■Storyboardを削除します

■Main Interfaceの変更
左側のプロジェクトディレクトリを選択すると、プロジェクトのプロパティが表示されます
その中の

General > Deployment Info > Main Interface
の部分を空欄にしておきます




■ソースコード
下記のように編集します

```swift: AppDelegate.swift
import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        window = UIWindow(frame: UIScreen.main.bounds)
        window?.rootViewController = MainTabBarViewController()
        window?.makeKeyAndVisible()
        
        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
    }

    func applicationWillTerminate(_ application: UIApplication) {
    }
}
```


```Swift: Nav1ViewController.swift
// 初期表示されるpushボタンがあるページ

import UIKit
import SnapKit

final class Nav1ViewController: UIViewController {
    private lazy var container: UIView = {
        let container = UIView()
        container.backgroundColor = UIColor.gray
        
        let button = UIButton(type: .system)
        container.addSubview(button)
        button.setTitle("push", for: .normal)
        button.tintColor = UIColor.white
        button.backgroundColor = UIColor.blue
        button.addTarget(self, action: #selector(onTappedPush(_:)), for: .touchUpInside)
        button.snp.makeConstraints { make in
            make.width.equalTo(200)
            make.height.equalTo(40)
            make.center.equalTo(container)
        }
        return container
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        navigationItem.title = "Nav1"
        self.view.addSubview(container)
        container.snp.makeConstraints { make in
            make.edges.equalToSuperview()
        }
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    func onTappedPush(_ sender: UIButton) {
        print(sender)
        let vc = SecondViewController(titleName: "second")
        navigationController?.pushViewController(vc, animated: true)
    }
}
```

```Swift: SecondViewController.swift
// ボタンの遷移先画面

import Foundation
import UIKit

final class SecondViewController: UIViewController {
    let titleName: String
    
    init(titleName: String) {
        self.titleName = titleName
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder aDecoder: NSCoder) { fatalError("init(coder:) has not been implemented") }
    
    private lazy var container: UIView = {
        let container = UIView()
        container.backgroundColor = UIColor.yellow
        return container
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        navigationItem.title = titleName
        self.view.addSubview(container)
        container.snp.makeConstraints { make in
            make.edges.equalToSuperview()
        }
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}
```


```Swift: Nav2ViewController.swift
// ２つ目のタブの画面

import Foundation
import UIKit

final class Nav2ViewController: UIViewController {
    private lazy var tableView: UITableView = {
        let tableView = UITableView()
        tableView.delegate = self
        tableView.dataSource = self
        return tableView
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        navigationItem.title = "Nav2"
        view = tableView
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

extension Nav2ViewController: UITableViewDelegate {
    
}

extension Nav2ViewController: UITableViewDataSource {
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        return UITableViewCell()
    }
    
    public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 10
    }
}
```


```Swift: MainTabBarViewController.swift
// AppDelegate.swift　で起動時に開くように指定されている下部のタブ部分

import Foundation
import UIKit

final class MainTabBarViewController: UITabBarController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let vc = Nav1ViewController()   // コントローラのインスタンス
        vc.tabBarItem = UITabBarItem(tabBarSystemItem: .bookmarks, tag: 1)  // bookmarksという名前でタブとして組み込む
        let nv = UINavigationController(rootViewController: vc)
        
        let vc2 = Nav2ViewController()
        vc2.tabBarItem = UITabBarItem(tabBarSystemItem: .downloads, tag: 2)
        let nv2 = UINavigationController(rootViewController: vc2)
        
        setViewControllers([nv, nv2], animated: false)  
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}
```



※　SnapKit
このコードではSnapKitを使っているので、
SnapKitの導入が必要になります
この記事を参考にしてください
http://shige-mon.blogspot.jp/2017/09/cocoapodssnapkit.html



参考
http://qiita.com/star__hoshi/items/b38cf99457e781ed7625