没有textnode的权威标签列表(Authoritative list of tags without textnode)

 可达意味着苹果手表和iPhone通过蓝牙或WiFi连接。 这并不意味着iPhone应用程序正在运行。 如果可以访问，那么当您尝试从Apple Watch发送消息时，它会在后台启动iPhone应用程序。 您需要尽快分配WKSession委托，因为委托方法（sendMessage）很快就会触发。 我想你要说的是如果可以的话调用sendMessage，而不是使用transferUserInfo方法。 要做到这一点，首先在你的苹果手表上： 
 
func applicationDidFinishLaunching() {
    let session = WCSession.defaultSession()
    session.delegate = self
    session.activateSession()

    // NOTE: This should be your custom message dictionary
    // You don't necessarily call the following code in
    // applicationDidFinishLaunching, but it is here for
    // the simplicity of the example. Call this when you want to send a message.
    let message = [String:AnyObject]()

    // To send your message.
    // You could check reachable here, but it could change between reading the
    // value and sending the message. Instead just try to send the data and if it
    // fails queue it to be sent when the connection is re-established.
    session.sendMessage(message, replyHandler: { (response) -> Void in
        // iOS app got the message successfully
    }, errorHandler: { (error) -> Void in
        // iOS app failed to get message. Send it in the background
        session.transferUserInfo(message)
    })
}
 
 然后，在你的iOS应用程序中： 
 
// Do this here so it is setup as early as possible so
// we don't miss any delegate method calls
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    self.watchKitSetup()  
    return true
}

func watchKitSetup() {
    // Stop if watch connectivity is not supported (such as on iPad)
    if (WCSession.isSupported()) {
        let session = WCSession.defaultSession()
        session.delegate = self
        session.activateSession()
    }
}

func session(session: WCSession, didReceiveMessage message: [String : AnyObject], replyHandler: ([String : AnyObject]) -> Void) {
    // Handle the message from the apple watch...
    dispatch_async(dispatch_get_main_queue()) {
        // Update UI on the main thread if necessary
    }
}

func session(session: WCSession, didReceiveUserInfo userInfo: [String : AnyObject]) {
    // Handle the message from the apple watch...
    dispatch_async(dispatch_get_main_queue()) {
        // Update UI on the main thread if necessary
    }
}

Reachable means the apple watch and iPhone are connected via bluetooth or wifi. It doesn't necessarily mean the iPhone app is running. If reachable is true, when you try to sendMessage from the apple watch it will launch the iPhone app in the background. You need to assign the WKSession delegate as soon as possible because the delegates methods (sendMessage) will fire soon. I think what you are saying you want to do is call sendMessage if you can, and it not use the transferUserInfo method instead. To do this, first on your apple watch:
 
func applicationDidFinishLaunching() {
    let session = WCSession.defaultSession()
    session.delegate = self
    session.activateSession()

    // NOTE: This should be your custom message dictionary
    // You don't necessarily call the following code in
    // applicationDidFinishLaunching, but it is here for
    // the simplicity of the example. Call this when you want to send a message.
    let message = [String:AnyObject]()

    // To send your message.
    // You could check reachable here, but it could change between reading the
    // value and sending the message. Instead just try to send the data and if it
    // fails queue it to be sent when the connection is re-established.
    session.sendMessage(message, replyHandler: { (response) -> Void in
        // iOS app got the message successfully
    }, errorHandler: { (error) -> Void in
        // iOS app failed to get message. Send it in the background
        session.transferUserInfo(message)
    })
}
 
Then, in your iOS app:
 
// Do this here so it is setup as early as possible so
// we don't miss any delegate method calls
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    self.watchKitSetup()  
    return true
}

func watchKitSetup() {
    // Stop if watch connectivity is not supported (such as on iPad)
    if (WCSession.isSupported()) {
        let session = WCSession.defaultSession()
        session.delegate = self
        session.activateSession()
    }
}

func session(session: WCSession, didReceiveMessage message: [String : AnyObject], replyHandler: ([String : AnyObject]) -> Void) {
    // Handle the message from the apple watch...
    dispatch_async(dispatch_get_main_queue()) {
        // Update UI on the main thread if necessary
    }
}

func session(session: WCSession, didReceiveUserInfo userInfo: [String : AnyObject]) {
    // Handle the message from the apple watch...
    dispatch_async(dispatch_get_main_queue()) {
        // Update UI on the main thread if necessary
    }
}