send message from AppleWatch to iPhone app using watchOS2

Question

I tried to send message to iPhone app from iwatchExtension(on ButtonClick) using WCSession method like

[[WCSession defaultSession] sendMessage:applicationData
                                   replyHandler:^(NSDictionary *reply)

But delegate method - (void)session:(WCSession *)session didReceiveMessage: is not getting called.

when I tried same while passing data from iPhone to iWatch, it works properly. All delegate methods get called properly in "Extension Delegate" class.

Answer 1

If you check the definition of WCSession delegate methods you will find a minor difference about their receiving nature. Check the bold quote.

/** Called on the delegate of the receiver. Will be called on startup if the incoming message caused the receiver to launch. */
- (void)session:(WCSession *)session didReceiveMessage:(NSDictionary *)message;

/** Called on the delegate of the receiver when the sender sends a message that expects a reply . Will be called on startup if the incoming message caused the receiver to launch. */
- (void)session:(WCSession *)session didReceiveMessage:(NSDictionary *)message replyHandler:(void(^)(NSDictionary *replyMessage))replyHandler;

As you are providing a non-null parameter for replyHandler: , you should be receiving the message in other delegate ie -(void)session:(WCSession *)session didReceiveMessage:(NSDictionary<NSString *, id> *)message .

You are using [WCSession defaultSession] sendMessage: ...] for communication, which lacks the delegate assignment plus you have not activated the session.

In your Extention class, create an ivar for WCSession and write this code

- (void)awakeWithContext:(id)context {
    [super awakeWithContext:context];
    // Configure interface objects here.    
    if([WCSession isSupported])
    {
        session = [WCSession defaultSession];
        session.delegate = self;
        [session activateSession];
    }    
}

and then send message like [session sendMessage:applicationData replyHandler:^(NSDictionary *reply) .

In your AppDelegate.m file just create and instance of WCSession and activate it and use the correct delegate method to capture the message.

if([WCSession isSupported]) {
     appSession = [WCSession defaultSession];
     appSession.delegate = self;
     [appSession activateSession];
}

I believe this should solve your problem.