How to populate table rows, using a [String] array sent from iPhone by Watch Connectivity?

问题

Basically, it's passing the array fine. It's just when trying to use the enumerated array as the tablerows, it says nil found.

PHONE

import UIKit
import WatchConnectivity

class ViewController: UIViewController, WCSessionDelegate {

    @IBOutlet weak var sendButton: UIButton!

    var watchSession: WCSession?
    var arrayCustom = ["thing1", "thing2"]

    override func viewDidLoad() {
        super.viewDidLoad()

        if(WCSession.isSupported()) {
            watchSession = WCSession.defaultSession()
            watchSession?.delegate = self
            watchSession?.activateSession()
        }

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }


    @IBAction func sendArray(sender: AnyObject) {
        sendToWatch()

    }


    private func sendToWatch() {
        do {
            let applicationDict = ["Array1": arrayCustom]
            try WCSession.defaultSession().updateApplicationContext(applicationDict)
        }

        catch {
            print(error)
        }
    }
}

WATCHKIT

private func loadThCust() {

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

func session(session: WCSession, didReceiveApplicationContext applicationContext: [String : AnyObject]) {

        dispatch_async(dispatch_get_main_queue()) { () -> Void in

            if let retrievedArray1 = applicationContext["Array1"] as? [String] {
                self.custArray = retrievedArray1
                print(self.custArray)
            }
            for (index, thName) in self.custArray.enumerate() {
                let row2 = self.choiceTable.rowControllerAtIndex(index) as! ChoiceTableRowController
                row2.choiceLabel.setText(thName)
                }
            }
        }

My problem is I'm getting this console output + error whenever I try and load the TableView:

["thing1", "thing2"]
2016-02-24 03:21:25.912 WristaRoo WatchKit Extension[9401:243561] Error - attempt to ask for row 0. Valid range is 0..0
fatal error: unexpectedly found nil while unwrapping an Optional value

Does anyone have any idea why the unwrapped value is still nil? I was hoping that once I get it set and can see that there are values in the [String] array, it could enumerate it, but it seems like they are just invisible.

回答1:

You started the question with the statement, "Basically, It's passing the array fine" so it's not a Watch Connectivity issue.

You simply didn't specify the number of rows for choiceTable before iterating through your array.

choiceTable.setNumberOfRows(custArray.count, withRowType: "ChoiceTableRowController")

Determining the problem from the console output:

Error - attempt to ask for row 0. Valid range is 0..0

rowControllerAtIndex: returns (an Optional which is) nil when its index is out of bounds.

The row controller object, or nil if there are no row controllers yet or index is out of bounds.

You tried to access a row which didn't exist, leading to a bounds warning.
fatal error: unexpectedly found nil while unwrapping an Optional value
```
row2.choiceLabel.setText(thName)
```
row2 is nil.

You should be able to easily track down bugs like this in the debugger. If you examined row2 and saw that it was nil, you'd realize that the problem wasn't with the array itself, but that the table has no rows.

来源：https://stackoverflow.com/questions/35596888/how-to-populate-table-rows-using-a-string-array-sent-from-iphone-by-watch-con

标签

swift

watchkit

watch-os-2

watchconnectivity