无法快速显示第一个视图控制器将值传递给第二个视图控制器

Posted 2023-02-23

【中文标题】无法快速显示第一个视图控制器将值传递给第二个视图控制器

【英文标题】：Unable to show first viewcontroller passed values to second viewcontroller in swift

【发布时间】：2020-08-11 10:19:51

【问题描述】：

我的第二个 viewcontroller 包含 mkmapview.. 所有时间地图必须仅在文本字段中显示当前位置地址值，但是当我从 firstviewcontroller 发送值时，只有它应该在其文本字段中显示 firstviewcontroller 的地址值

最初显示当前位置值的第二个视图控制器文本字段（如：城市、街道等）

现在我将第一个 viewcontroller 地址发送到 secondviewcontroller.. 但是这里 secondviewcontroller 总是只显示当前位置值.. 为什么？

firstvc 代码：向 2ndvc 发送地址：

 func btnEditTapped(cell: EditAddressTableViewCell) 
    if let indexPath = self.addeditTableview.indexPath(for: cell)
        print("edit button address index \(indexPath.row)")
          let viewController = self.storyboard?.instantiateViewController(withIdentifier: "ProfileAddressViewController") as! ProfileAddressViewController
        
        var addrLo = addressArray[indexPath.row]

        print("in edit total mode address \(addrLo.pincode)")// in console in edit total mode address Optional("530013")
        viewController.editPincode = addrLo.pincode
        viewController.editStree = addrLo.streetName
        viewController.editColony = addrLo.city
        
    self.navigationController?.pushViewController(viewController, animated: true)
    

我的 secondvc 代码：这里我无法显示 firstvc 的值，为什么？

class ProfileAddressViewController: UIViewController, CLLocationManagerDelegate, UISearchBarDelegate, DataEnteredDelegate 


var coordinate: CLLocationCoordinate2D = CLLocationCoordinate2D()
let locationManager = CLLocationManager()
   
var addressModel : ProfileModelUserAddress?
var editAddArray = [String]()

var addressArray = [String]()

@IBOutlet weak var titleNameLabel: UILabel!
@IBOutlet weak var backButton: UIButton!
@IBOutlet weak var pincodeField: UITextField!
@IBOutlet weak var cityField: UITextField!
@IBOutlet weak var streetField: UITextField!
@IBOutlet weak var mapView: MKMapView!

var editPincode: String?
var editStree: String?
var editColony: String?
var isEdit = Bool()


override func viewDidLoad() 
    super.viewDidLoad()
     self.locationManager.requestAlwaysAuthorization()
    if CLLocationManager.locationServicesEnabled() 
        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
        locationManager.startUpdatingLocation()
    
    if isEdit 
        titleNameLabel.text = "Edit Address"
        
        pincodeField.text = editPincode
        streetField.text = editStree
        colonyField.text = editColony
        
    

   
@IBAction func backBtnClicked(_ sender: Any) 
    self.navigationController?.popViewController(animated: true)


func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) 
    guard let _: CLLocationCoordinate2D = manager.location?.coordinate else  return 

    let userLocation :CLLocation = locations.last! as CLLocation
    latitude = userLocation.coordinate.latitude
    logitude = userLocation.coordinate.longitude
    let geocoder = CLGeocoder()
    geocoder.reverseGeocodeLocation(userLocation)  (placemarks, error) in
        if (error != nil)
            print("error in reverseGeocode")
        
        let placemark = placemarks! as [CLPlacemark]

        if placemark.count>0
            let placemark = placemarks![0]
            print(placemark.locality!)
            print(placemark.administrativeArea!)
            print(placemark.country!)
            let placemarkDictonary: NSDictionary=placemark.addressDictionary as! NSDictionary
            self.pincodeField.text=placemarkDictonary["ZIP"] as? String
            self.cityField.text=placemarkDictonary["City"] as? String
            self.streetField.text=placemarkDictonary["Street"] as? String
        
    

    let center = CLLocationCoordinate2D(latitude: latitude!, longitude: logitude!)

    let region = MKCoordinateRegion(center: center, span: MKCoordinateSpan(latitudeDelta: 0.01, longitudeDelta: 0.01))
    mapView.setRegion(region, animated: true)
    let myAnnotation: MKPointAnnotation = MKPointAnnotation()
    myAnnotation.coordinate = CLLocationCoordinate2DMake(userLocation.coordinate.latitude, userLocation.coordinate.longitude);
    myAnnotation.title = "Current location"
    mapView.addAnnotation(myAnnotation)

请告诉我，如何在第二个 vc 中显示 firstvc 传递的值

【问题讨论】：

将此行添加到您的 firstVC 'viewController. isEdit = true'

@BijenderSinghShekhawat，如果我给 'viewController. isEdit = true' 标题正在改变，但 pincodeField、streetField、colonyField 没有改变……为什么

我不知道...您应该逐步调试以了解实际情况

@BijenderSinghShekhawat，谢谢你知道了

【参考方案1】：

您是否在其他地方为isEdit 设置了值？如果不是，isEdit 的初始值将是 false，因为您使用的是 Bool 的初始化程序，默认情况下返回 false，因此，您的代码会为 if 内的文本字段初始化值语句永远不会运行。这就是为什么您看不到从第一个 VC 传递的值的原因。

【讨论】：

如果我给 'viewController. isEdit = true' 标题正在改变但 pincodeField、streetField、colonyField 没有改变......为什么？