最近學(xué)習(xí)swift有點(diǎn)迷茫，不知道從和入手，所以決定回顧一下學(xué)習(xí)了什么東西，首先從應(yīng)用的生命周期說(shuō)起

import UIKit

@UIApplicationMain

class AppDelegate: UIResponder, UIApplicationDelegate ?

{?

var window: UIWindow?

// 當(dāng)應(yīng)用程序已經(jīng)加載到內(nèi)存是調(diào)用該方法

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

print("程序被加載到內(nèi)存")

return true }

// 當(dāng)應(yīng)用程序取消激活狀態(tài)時(shí)調(diào)用該方法

func applicationWillResignActive(_ application: UIApplication)

{ print("取消激活") }

// 當(dāng)應(yīng)用程序已經(jīng)進(jìn)入到后臺(tái)時(shí)調(diào)用該方法

func applicationDidEnterBackground(_ application: UIApplication) { print("已經(jīng)進(jìn)入后臺(tái)") }

// 當(dāng)應(yīng)用程序進(jìn)入前臺(tái)時(shí)調(diào)用該方法

func applicationWillEnterForeground(_ application: UIApplication) { print("將要進(jìn)入前臺(tái)") }

// 當(dāng)應(yīng)用程序已經(jīng)被激活時(shí)調(diào)用該方法

func applicationDidBecomeActive(_ application: UIApplication) { print("程序被激活") }

// 當(dāng)應(yīng)用程序結(jié)束時(shí)調(diào)用該方法

func applicationWillTerminate(_ application: UIApplication) { print("程序結(jié)束") } } ?