swift - 将值传递给前一个 viewController，委托(delegate)方法未被调用

Question

我正在从一个函数中获取 schoolAddress 的值。 View 消失后，我传递了 schoolAddress 的值。我试图将学校地址的值从 GeoDetailsVC 传递给 EditChildPoofileVC ..提前谢谢

protocol DataEnteredDelegate : class {
    func setLocations(info: String)
}

class GeoDetailsVC: UIViewController{
    weak var delegate: DataEnteredDelegate? = nil
    var schoolAddress: String = ""

    override func viewDidDisappear(animated: Bool) {
        self.delegate?.setLocations(self.schoolAddress)
        print(schoolAddress)
    }
}

class EditChildProfileVC: UIViewController, DataEnteredDelegate  {

    var locationSentFromGeoDetailsVC:String?
    @IBOutlet weak var schoolAddressTF: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()
        print("EditChildProfileVC")
        self.title = ChildName
    }

    func setLocations(info: String) {
        NSOperationQueue.mainQueue().addOperationWithBlock {
            self.locationSentFromGeoDetailsVC = info
            self.schoolAddressTF.text = self.locationSentFromGeoDetailsVC
        }
    }

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue == "GeoDetailsSegue" {
            let vc = segue.destinationViewController as! GeoDetailsVC
            vc.delegate = self
        }
    }
}

Answer 1

尝试将 segue == "GeoDetailsS​​egue" 更改为 segue.identifier == "GeoDetailsS​​egue"，如下所示:

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    guard let segueIdentifier = segue.identifier else { return }
    if segueIdentifier == "GeoDetailsSegue",
        let vc = segue.destinationViewController as? GeoDetailsVC {
        vc.delegate = self
    }
}