Watch connectivity example

AppDelegate.swift

import UIKit
import WatchConnectivity

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        WCSession.default.delegate = self
        WCSession.default.activate()
        return true
    }
}

extension AppDelegate: WCSessionDelegate {

    func session(_ session: WCSession, didReceiveMessage message: [String : Any]) {
        // TODO: Converter a mensagem para o tipo esperado (no exemplo, usei String)
        guard let messageContent = message["mensagemDoWatchOSParaiOS"] as? String else { return }

        print(messageContent)
    }

    func session(_ session: WCSession, activationDidCompleteWith activationState: WCSessionActivationState, error: Error?) {}

    func sessionDidBecomeInactive(_ session: WCSession) {}

    func sessionDidDeactivate(_ session: WCSession) {}
}

ExtensionDelegate.swift

import WatchKit
import WatchConnectivity

class ExtensionDelegate: NSObject, WKExtensionDelegate {

    func applicationDidFinishLaunching() {
        WCSession.default.delegate = self
        WCSession.default.activate()
    }

    func handle(_ backgroundTasks: Set<WKRefreshBackgroundTask>) {
        // ...
    }
}

extension ExtensionDelegate: WCSessionDelegate {

    func session(_ session: WCSession, activationDidCompleteWith activationState: WCSessionActivationState, error: Error?) {}

    func session(_ session: WCSession, didReceiveMessage message: [String : Any]) {
        // TODO: Converter a mensagem para o tipo esperado (no exemplo, usei String)
        guard let messageContent = message["mensagemDoiOSParaWatchOS"] as? String else { return }

        print(messageContent)
    }
}

InterfaceController.swift

// Exemplo no lado do WatchOS
import WatchConnectivity

class InterfaceController: WKInterfaceController {

    override func willActivate() {
        super.willActivate()
        let message = ["mensagemDoWatchOSParaiOS": "Tchau, cara de pau"]
        WCSession.default.sendMessage(message, replyHandler: nil, errorHandler: nil)
    }
}

ViewController.swift

// Exemplo no lado do iOS
import UIKit
import WatchConnectivity

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        let message = ["mensagemDoiOSParaWatchOS": "Oi, cara de boi"]
        WCSession.default.sendMessage(message, replyHandler: nil, errorHandler: nil)
    }
}