swift - 以编程方式在 Swift 3 中的两个 UIViewController 之间导航

Question

在我的应用程序中有两个 UIViewController(首先，用户选择角色，其次，显示角色信息)。 尝试从代码做所有事情。所以我的代码:

AppDelegate.swift:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    self.window = UIWindow(frame: UIScreen.main.bounds)
    guard let window = self.window else {
        return false
    }
    UIApplication.shared.statusBarStyle = .lightContent

    let viewController = ViewController()
    let navigationController = UINavigationController(rootViewController: viewController)

    window.rootViewController = navigationController
    window.makeKeyAndVisible()

    return true
}

View Controller :UIViewController

...
    func buttonPressed(sender: UIButton) {
        guard let typeName = sender.title(for: .normal), let unitType = UnitType(rawValue: typeName) else {
            return
        }
        let unitViewController = UnitViewController(unitType: unitType)
        let navigationController = UINavigationController(rootViewController: unitViewController)
        self.present(navigationController, animated: true, completion: nil)
    }

和 UnitViewController:UIViewController(显示所选角色的信息):

...
    fileprivate func setupNavigationBar() {
        let backButton = UIBarButtonItem(title: "<", style: .plain, target: self, action: #selector(backToViewController(sender:)))
        self.navigationItem.setLeftBarButton(backButton, animated: true)
        self.navigationItem.titleView?.backgroundColor = AppColor.Black.color
        self.navigationItem.titleView?.tintColor = .white
        self.navigationItem.title = "\(self.unitType.rawValue)"
    }

    func backToViewController(sender: AnyObject) {
        self.dismiss(animated: true) {
            let viewController = ViewController()
            let navigationController = UINavigationController(rootViewController: viewController)
            self.present(navigationController, animated: true, completion: nil)
        }
    }

所以我有两个屏幕:

好吧，我有一些问题: 1.获取

2016-12-02 05:48:21.855 The API Awakens[16402:551729] Warning: Attempt to present on whose view is not in the window hierarchy! warning when press 'back' button in UnitViewController. What I am doing wrong?

1. NavigationBar 的灰色背景色和黑色。怎么改成黑白的？

2. 如何获取 UIBarButtonItem 的“系统”后退按钮，而不仅仅是带有标题“<”的 .plain？所以我的 UnitViewController 导航栏应该是这样的:

任何帮助将不胜感激!

更新 1: 1.警告消失了，感谢@dip 2. 使导航栏变暗，感谢@aznelite89。 但是，在 AppDelegate.swift 中有我的代码:

UINavigationBar.appearance().barTintColor = AppColor.Black.color

AppColor.Black 与我在 ViewController 中用作背景的颜色完全相同，但现在看起来是这样:

看起来 NavigationBar 的 alpha 不是 1.0...

更新 2: NavigationBar 的颜色和我使用的颜色之间的区别是 RGB 值是 13，所以我已经破解了它设置 NavigationBar 的颜色，RGB 值比原始颜色少 13...现在可以了

Answer 1

1. 试试这个:-

   let viewController = ViewController()
   viewController.modalPresentationStyle = .overCurrentContext
   window?.rootViewController?.present(viewController, animated: true, completion: nil)
   

2. 在 app delegate.swift 中添加:-

   UINavigationBar.appearance().barTintColor = UIColor.black
   

3. 您可以在 Storyboard属性检查器上更改这些属性