Ewerson Ewerson - 1 year ago 303
iOS Question

reachability bug in Xcode 8 e Swift 3

I have a huge problem!
I'm trying to implement reachability in an app using Xcode 8 Beta 3 and Swift.

When the user have internet (wifi or 4G): the background turns green. If you will not the background it will be red. And if the user accessing internet in a cellular, the background it will be yellow.

The code runs well, but when I turn off the wifi, it breaks

Here my github project - my "single view application"


Answer Source

You need to fix your method selector. Try like this.


import UIKit

class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        reachability = Reachability.forInternetConnection()
        return true
    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    func applicationWillTerminate(_ application: UIApplication) {


View Controller

import UIKit
import SystemConfiguration

var reachability = Reachability()

class ViewController: UIViewController {

    override func viewDidLoad() {

        NotificationCenter.default.addObserver(self, selector: #selector(reachabilityStatusChanged(_:)), name: .reachabilityChanged, object: nil)


    func updateInterfaceWithCurrent(networkStatus: NetworkStatus) {
        switch networkStatus {
        case NotReachable:
            view.backgroundColor = .red
            print("No Internet")
        case ReachableViaWiFi:
            view.backgroundColor = .green
            print("Reachable Internet")
        case ReachableViaWWAN:
            view.backgroundColor = .yellow
            print("Reachable Cellular")

    override func viewWillAppear(_ animated: Bool) {
        updateInterfaceWithCurrent(networkStatus: reachability.currentReachabilityStatus())

    func reachabilityStatusChanged(_ sender: NSNotification?) {
        guard let networkStatus = (sender?.object as? Reachability)?.currentReachabilityStatus() else { return }
        updateInterfaceWithCurrent(networkStatus: networkStatus)
    override func viewWillDisappear(_ animated: Bool) {
        NotificationCenter.default.removeObserver(self, name: .reachabilityChanged, object: nil)
    override func didReceiveMemoryWarning() {
        // Dispose of any resources that can be recreated.