Upgrade to Swift 5.1In this tutorial, we will learn how to send data from iPhone to Apple watch and Apple watch to iPhone using Swift 5.1. As we all familiar that Apple watch apps demands are keep growing these days, keeping in mind this tutorial maybe helpful for you.
We are going to achieve below.
Now let’s start coding
-Create a new project and choosewatchOS and select iOS App with WatchKit App.
Notification Scene as per your uses.
Design your Storyboard
– Open yourMain.storyboard and go to ViewController nib file.– Add a
UILabel and UIButton over the View.
IBOutlet of UILabel with name label-Add
IBAction function to UIButton with name tapSendDataToWatch
Move to your UIViewController Class
Open yourViewController Class and make below changes
import UIKit
import WatchConnectivity//1
class ViewController: UIViewController {
var session: WCSession?//2
@IBOutlet weak var label: UILabel!//3
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
self.configureWatchKitSesstion()//4
}
func configureWatchKitSesstion() {
if WCSession.isSupported() {//4.1
session = WCSession.default//4.2
session?.delegate = self//4.3
session?.activate()//4.4
}
}
//5
@IBAction func tapSendDataToWatch(_ sender: Any) {
if let validSession = self.session, validSession.isReachable {//5.1
let data: [String: Any] = ["iPhone": "Data from iPhone" as Any] // Create your Dictionay as per uses
validSession.sendMessage(data, replyHandler: nil, errorHandler: nil)
}
}
}
// WCSession delegate functions
extension ViewController: WCSessionDelegate {
func sessionDidBecomeInactive(_ session: WCSession) {
}
func sessionDidDeactivate(_ session: WCSession) {
}
func session(_ session: WCSession, activationDidCompleteWith activationState: WCSessionActivationState, error: Error?) {
}
func session(_ session: WCSession, didReceiveMessage message: [String : Any]) {
print("received message: \(message)")
DispatchQueue.main.async { //6
if let value = message["watch"] as? String {
self.label.text = value
}
}
}
}
WatchConnectivity framework, this will help to connect the iPhone and watch2.
WCSession will help us to communicate between iOS and WatckKit3. This is
IBOutlet of UILabel4. Calling
configureWatchKitSesstion to initialize WCSession4.1 Check that
WCSession is supported or not4.2 Initializing
WCSession4.3 Set
WCSessionDelegate to session4.4 Activate
WCSession in order to transfer data5. This is
IBAction function on UIButton5.1 First check if Apple watch is reachable then send the data to Apple watch using
sendMessage function of WCSession6 Receiving data when Apple watch send to iPhone
Move to Watch and Open Watch Interface.storyboard
– OpenInterface.storyboard and select InterfaceController nib file.– Add a
WKInterfaceLabel and WKInterfaceButton over the InterfaceController nib file.– Create
IBOutlet of WKInterfaceLabel and add IBAction on WKInterfaceButton with name tapSendToiPhone
Move to InterfaceController Class
OpenInterfaceController Class and make below changes.
import WatchKit
import WatchKit
import Foundation
import WatchConnectivity //**1
class InterfaceController: WKInterfaceController {
@IBOutlet weak var label: WKInterfaceLabel!//**2
let session = WCSession.default//**3
override func awake(withContext context: Any?) {
super.awake(withContext: context)
// Configure interface objects here.
session.delegate = self//**4
session.activate()//**5
}
override func willActivate() {
// This method is called when watch view controller is about to be visible to user
super.willActivate()
}
override func didDeactivate() {
// This method is called when watch view controller is no longer visible
super.didDeactivate()
}
@IBAction func tapSendToiPhone() {//**6
let data: [String: Any] = ["watch": "data from watch" as Any] //Create your dictionary as per uses
session.sendMessage(data, replyHandler: nil, errorHandler: nil) //**6.1
}
}
extension InterfaceController: WCSessionDelegate {
func session(_ session: WCSession, activationDidCompleteWith activationState: WCSessionActivationState, error: Error?) {
}
func session(_ session: WCSession, didReceiveMessage message: [String : Any]) {
print("received data: \(message)")
if let value = message["iPhone"] as? String {//**7.1
self.label.setText(value)
}
}
}
WatchConnectivity framework2. Crate
IBoutlet of WKInterfaceLabel which we have added over nib file above3. Get a default object of
WCSession4. Assign
WCSessionDelegate to the session object5. Activate
WCSession in order to transfer data between iOS and WatchKit6. This is
IBAction function which we have added on WKInterfaceButton6.1 Send data to iPhone using
sendMessage function of WCSession7. When the iPhone send data to then watch then
didReceiveMessage delegate function will invoke.7.1 Get the message which is sent from iPhone and set this to
WKInterfaceLabelNow run your code
Note: If you forget to activate your session then, you will get an error log “swift wcsession counterpart app not installed” message while sharing data
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Greetings! Very helpful advice on this article! It is the little changes that make the biggest changes. Thanks a lot for sharing!
Hello
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telling all about that.
Hi, I setup the exact code and UI in XCODE 10.2 for iOS 13.3 simulator and watchOS 6.1. I checked every line exactly in this page and checked the compatibilty with swift 4.0 4.2 and 5.0. there is no warning, and no error; but no message send and received between simulators. I really don’t know what the problem is?
We have shared a source code with you, please check.
Same thing( did it twice – first time it was no response from phone and watch (without any error), second time it is error: WatchKit Extension[21282:1294188] [WC] WCSession iOS app not installed
The post is upgrades to Swift 5.1.
Could out fix it? Same here, also with other projects….
Hi Stefan,
The issue is reloved, please take a look at the updated post.
Hi,
Thanks for the tutorial. I have copied the whole code. My question is about how to run it. Which target to use, iPhone or Watch ? Which scheme to use ? I have defined one with an iPhone 7 + a watch S4 44. Either I get “app counterpart not installed” and I see only the iPhone screen. Either I get the two screens but the apps ignore each other. Any help ? I have restarted Xcode about 10 times already…
Thanks
Hello Author. I created this exactly and nothing is happening! Xcode 11.4 swift 5.0 Simulator: iOS 13.4 watchOS 6.2
thank you
Hello All, I found problem and fix.
“Check your WatchKit Extention target.
– Uncheck “Supports Running Without iOS App Installation”
”
I did and sends data back and forth now. Thank you.
Question1: I’d like to send from watch a Struct. How do we do that? thank you.
Question 2: On phone when received data I like it to automatically do something, like create an EKEvent? Receive code has to go in App Delegate? thank you, we can discuss in email if better. Regards, Mike
OMG Thank you so much saved my life.
Hello Author.
Thanks for the easy to understand sample code. This sample code was used to create my app. Thank you very much.