AppDelegate启动界面 判断是否为第一次启动

/// Mark: - 跳转时调用storyboard才会显示sotryboard上建的界面，否则为纯代码形式！

var window: UIWindow?

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

window?.makeKeyAndVisible()

/// 得到当前应用的版本号

let infoDictionary = Bundle.main.infoDictionary

let currentAppVersion = infoDictionary!["CFBundleShortVersionString"] as! String

/// 取出之前保存的版本号

let userDefaults = UserDefaults.standard

let appVersion = userDefaults.string(forKey: "appVersion")

let storyboard = UIStoryboard(name: "Main", bundle: nil)

/// 如果 appVersion 为 nil 说明是第一次启动；如果 appVersion 不等于 currentAppVersion 说明是更新了

if appVersion == nil || appVersion != currentAppVersion {

/// 保存最新的版本号

userDefaults.setValue(currentAppVersion, forKey: "appVersion")

let guideViewController = storyboard.instantiateViewController(withIdentifier: "GuideViewController") as! GuideViewController

self.window?.rootViewController = guideViewController

}else {

///Mark: -  调用storyboard才会显示界面，否则为纯代码形式！

let tabBarController =  storyboard.instantiateViewController(withIdentifier: "TabBarController") as! UITabBarController

}

///Mark: -  调用storyboard才会显示sotryboard上建的界面，否则为纯代码形式！

//            let storyboard = UIStoryboard(name: "Main", bundle: nil)

//            let tabBarController =  storyboard.instantiateViewController(withIdentifier: "TabBarController") as! UITabBarController

//            self.window?.rootViewController = tabBarController

return true

}

原文GitHub地址：https://github.com/GuiminChu/JianshuExample/blob/master/CustomPresentationViewController/CustomPresentationViewController/CustomPresentationController/CustomPresentationController.swift