我的观点是:

a)设置导航栏。barTintColor / titleTextAttributes工作在任何视图(推，添加..等在init..

B)设置外观并非处处适用:

你可以在AppDelegate上调用它 ”“一级视图 如果你在随后的推送视图中再次调用它，MNOT是否工作

SwiftUI 注释：

a)不适用(没有navigationBar，除非你通过UIViewControllerRepresentable trick..) b)对SwiftUI有效:相同的行为。

如果你使用iOS 13或14和大标题，并想改变导航栏的颜色，使用以下代码:

参考barTintColor不适用时导航栏是大标题

    fileprivate func setNavigtionBarItems() {
        if #available(iOS 13.0, *) {
            let appearance = UINavigationBarAppearance()
            appearance.configureWithDefaultBackground()
            appearance.backgroundColor = .brown
//            let naviFont = UIFont(name: "Chalkduster", size: 30) ?? .systemFont(ofSize: 30)
//            appearance.titleTextAttributes = [NSAttributedString.Key.font: naviFont]
            
            navigationController?.navigationBar.prefersLargeTitles = true
            navigationController?.navigationBar.standardAppearance = appearance
            navigationController?.navigationBar.scrollEdgeAppearance = appearance
            //navigationController?.navigationBar.compactAppearance = appearance
        } else {
            // Fallback on earlier versions
            navigationController?.navigationBar.barTintColor = .brown
        }
    }

这花了我1个小时来找出我的代码中的错误:(，因为我使用大标题，很难用largeTitle改变tintColor，为什么苹果让它这么复杂，这么多行只是做一个tintColor的navigationBar。

这里有一些非常基本的外观定制，你可以应用于整个应用程序:

UINavigationBar.appearance().backgroundColor = UIColor.greenColor()
UIBarButtonItem.appearance().tintColor = UIColor.magentaColor()
//Since iOS 7.0 UITextAttributeTextColor was replaced by NSForegroundColorAttributeName
UINavigationBar.appearance().titleTextAttributes = [UITextAttributeTextColor: UIColor.blueColor()]
UITabBar.appearance().backgroundColor = UIColor.yellowColor();

斯威夫特5.4.2:

UINavigationBar.appearance().backgroundColor = .green // backgorund color with gradient
// or
UINavigationBar.appearance().barTintColor = .green  // solid color
    
UIBarButtonItem.appearance().tintColor = .magenta
UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor : UIColor.blue]
UITabBar.appearance().barTintColor = .yellow

更多关于UIAppearance API在Swift你可以阅读这里。

在AppDelegate中试试这个:

//MARK:- ~~~~~~~~~~setupApplicationUIAppearance Method
func setupApplicationUIAppearance() {

    UIApplication.shared.statusBarView?.backgroundColor = UIColor.clear

    var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }

    UINavigationBar.appearance().tintColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
    UINavigationBar.appearance().barTintColor =  UIColor.white
    UINavigationBar.appearance().isTranslucent = false

    let attributes: [NSAttributedString.Key: AnyObject]

    if DeviceType.IS_IPAD{
        attributes = [
            NSAttributedString.Key.foregroundColor: UIColor.white,
            NSAttributedString.Key.font: UIFont(name: "HelveticaNeue", size: 30)
            ] as [NSAttributedString.Key : AnyObject]
    }else{
        attributes = [
            NSAttributedString.Key.foregroundColor: UIColor.white
        ]
    }
    UINavigationBar.appearance().titleTextAttributes = attributes
}

iOS 13

func setupNavigationBar() {
    //        if #available(iOS 13, *) {
    //            let window = UIApplication.shared.windows.filter {$0.isKeyWindow}.first
    //            let statusBar = UIView(frame: window?.windowScene?.statusBarManager?.statusBarFrame ?? CGRect.zero)
    //            statusBar.backgroundColor = #colorLiteral(red: 0.2784313725, green: 0.4549019608, blue: 0.5921568627, alpha: 1) //UIColor.init(hexString: "#002856")
    //            //statusBar.tintColor = UIColor.init(hexString: "#002856")
    //            window?.addSubview(statusBar)
    //            UINavigationBar.appearance().tintColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
    //            UINavigationBar.appearance().barTintColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
    //            UINavigationBar.appearance().isTranslucent = false
    //            UINavigationBar.appearance().backgroundColor = #colorLiteral(red: 0.2784313725, green: 0.4549019608, blue: 0.5921568627, alpha: 1)
    //            UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor : UIColor.white]
    //        }
    //        else
    //        {
    UIApplication.shared.statusBarView?.backgroundColor = #colorLiteral(red: 0.2784313725, green: 0.4549019608, blue: 0.5921568627, alpha: 1)
    UINavigationBar.appearance().tintColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
    UINavigationBar.appearance().barTintColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
    UINavigationBar.appearance().isTranslucent = false
    UINavigationBar.appearance().backgroundColor = #colorLiteral(red: 0.2784313725, green: 0.4549019608, blue: 0.5921568627, alpha: 1)
    UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor : UIColor.white]
    //        }
}

扩展

extension UIApplication {

var statusBarView: UIView? {
    if responds(to: Selector(("statusBar"))) {
        return value(forKey: "statusBar") as? UIView
    }
    return nil
}}

UINavigationBar.appearance().barTintColor = UIColor(red: 46.0/255.0, green: 14.0/255.0, blue: 74.0/255.0, alpha: 1.0)
UINavigationBar.appearance().tintColor = UIColor.whiteColor()
UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName : UIColor.whiteColor()]

只需将这一行粘贴到代码中的didFinishLaunchingWithOptions中。

这个版本还删除了导航栏下的1px阴影线:

Swift 5:把这个放在你的AppDelegate didFinishLaunchingWithOptions中

UINavigationBar.appearance().barTintColor = UIColor.black
UINavigationBar.appearance().tintColor = UIColor.white
UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
UINavigationBar.appearance().isTranslucent = false
UINavigationBar.appearance().setBackgroundImage(UIImage(), for: .any, barMetrics: .default)
UINavigationBar.appearance().shadowImage = UIImage()