我已经四处搜索，似乎找不到为什么我的segue正在加载下一个视图控制器两次的答案。出于某种原因，它偶尔会发生，我会说按下getMyLocation按钮大约1/5。我想要发生的是用户按getMylocation并从那里抓取用户的坐标，存储数据，并使用存储的数据显示下一个视图。因此，我在performSegue中有didUpdatedLocations，因此我可以在调用segue之前存储数据。我应该注意到segue是在故事板中创建的，通过ctrl单击并将我的主视图拖动到下一个，而不是通过拖动按钮。
我的代码首先是第一个视图：
// Declare all IB Outlets
@IBOutlet weak var cityLabel: SpringTextField!
@IBOutlet weak var stateLabel: SpringTextField!
@IBOutlet weak var searchButton: SpringButton!
@IBOutlet weak var getLocationButton: SpringButton!
@IBOutlet weak var locationButton: UIButton!
@IBOutlet weak var citySearchButton: UIButton!
// Declare all variables
var latAndLong = ""
var city = ""
var state = ""
let locationManager = CLLocationManager()
let limitLength = 2
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
guard let locValue: CLLocationCoordinate2D = manager.location?.coordinate else { return }
let lat = locValue.latitude
let long = locValue.longitude
latAndLong = "\(lat),\(long)"
locationManager.stopUpdatingLocation()
self.performSegue(withIdentifier: "goToSecond", sender: self)
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidAppear(_ animated: Bool) {
// Declare text label delegates to allow control
cityLabel.delegate = self as UITextFieldDelegate
stateLabel.delegate = self as UITextFieldDelegate
// Define what tap to look for
let tap : UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(UIViewController.dismissKeyboard))
tap.cancelsTouchesInView = false
view.addGestureRecognizer(tap)
// Delgate Location Manager
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters
}
// Allow keyboard to switch text fields from city to state by pressing return
internal func textFieldShouldReturn(_ textField : UITextField) -> Bool {
if textField == cityLabel {
city = cityLabel.text!
textField.resignFirstResponder()
stateLabel.becomeFirstResponder()
}
if textField == stateLabel {
state = stateLabel.text!
performSegue(withIdentifier: "goToSecond", sender: self)
}
return true
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
var newLength = 0
if textField == stateLabel {
guard let text = textField.text else { return true }
newLength = text.count + string.count - range.length
return newLength <= 2
}
else if textField == cityLabel {
guard let text = textField.text else { return true }
newLength = text.count + string.count - range.length
return newLength <= 40
}
return true
}
// Location manager required function + store location variables + perform transition to next view
// Defines what happens when either "Get My Location" or "Search by city is pressed"
@IBAction func getMyLocationPressed(_ sender: Any) {
city = ""
state = ""
let status = CLLocationManager.authorizationStatus()
if status == .authorizedWhenInUse {
locationManager.startUpdatingLocation()
}
else if status == .notDetermined {
locationManager.requestWhenInUseAuthorization()
locationManager.startUpdatingLocation()
return
}
else if status == .denied || status == .restricted {
let alert = UIAlertController(title : "Location Services Disabled", message: "Please enable location, or search by City and State", preferredStyle: .alert)
let okAction = UIAlertAction(title: "OK",style: .default, handler: nil)
alert.addAction(okAction)
present(alert, animated: true, completion: nil)
return
}
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
print("didnt work")
}
@IBAction func getLocationPressed(_ sender: SpringButton) {
let status = CLLocationManager.authorizationStatus()
if status == .notDetermined {
locationManager.requestWhenInUseAuthorization()
return
}
else if status == .denied || status == .restricted {
let alert = UIAlertController(title : "Location Services Disabled", message: "Please enable location, or search by City and State", preferredStyle: .alert)
let okAction = UIAlertAction(title: "OK",style: .default, handler: nil)
alert.addAction(okAction)
present(alert, animated: true, completion: nil)
return
}
locationManager.startUpdatingLocation()
}
// Defines what happens during transition to next screen including what variables to send ober
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goToSecond" {
let nextVC = segue.destination as! SecondViewController
nextVC.cityAndState = (city) + "," + (state)
nextVC.latAndLong = latAndLong
}
}
}
我的第二个观点的代码：
var latAndLong = ""
var cityAndState = ""
@IBOutlet weak var tableView: UITableView!
var selectedRow = ""
var namesOfPictures = ["Activities-1", "Food", "Drinks", "Random"]
let display = ["Activities", "Food", "Drink", "Random"]
let cellColors = ["#4D606E","#3FBAC2","#D3D4D8","#F5F5F5"]
override func viewDidLoad() {
super.viewDidLoad()
configureTableView()
tableView.separatorStyle = .singleLine
tableView.register(UINib(nibName: "TableViewCell", bundle: nil), forCellReuseIdentifier: "realCell")
tableView.delegate = self
tableView.dataSource = self
// Do any additional setup after loading the view.
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "realCell", for: indexPath) as! TableViewCell
cell.backgroundView = UIImageView(image: UIImage(named: namesOfPictures[indexPath.row]))
cell.label.text = display[indexPath.row]
return cell
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return display.count
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print(latAndLong)
selectedRow = display[indexPath.row]
print(selectedRow)
tableView.deselectRow(at: indexPath, animated: true)
performSegue(withIdentifier: "goToActivities", sender: self)
}
func configureTableView() {
tableView.rowHeight = 152.0
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goToActivities" {
let nextVC = segue.destination as! ActivitiesViewController
nextVC.selectedItem = selectedRow
nextVC.cityAndState = cityAndState
nextVC.latAndLong = latAndLong
}
}
答案 0 :(得分：0)
CLLoction经理代表 - “didUpdateLocations：”即使在停止位置更新后也会多次触发
func locationManager（_ manager：CLLocationManager，didUpdateLocations locations：[CLLocation]）
获得有效的用户位置后，您必须将委托设置为nil
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
//After validating user location
locationManager.delegate = nil