我转换为Swift 4.我的tableview从firebase中提取数据并按距离用户位置组织它已停止工作。问题是我的用户位置不断变为零。我最近听说人们因为转换而遇到mapkit问题,但不确定这是否属于同一类别。所以说"让userLocation = CLLocation(纬度:纬度!,经度:经度!)"返回零。谢谢。
override func viewDidLoad() {
super.viewDidLoad()
searchController.searchResultsUpdater = self
searchController.dimsBackgroundDuringPresentation = false
definesPresentationContext = true
tableView.tableHeaderView = searchController.searchBar
locationManager.delegate = self
locationManager.distanceFilter = kCLLocationAccuracyNearestTenMeters
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.startUpdatingLocation()
locationManager.stopUpdatingLocation()
locationManager.requestAlwaysAuthorization()
getTableViewData()
refresher = UIRefreshControl()
refresher.attributedTitle = NSAttributedString(string: "Pull to refresh")
refresher.addTarget(self, action: #selector(RegisteredLocations.handleRefresh(refreshControl:)), for: UIControlEvents.valueChanged)
tableView.addSubview(refresher)
}
func getTableViewData() {
Database.database().reference().child("Businesses").queryOrdered(byChild: "businessName").observe(.childAdded, with: { (snapshot) in
let key = snapshot.key
if(key == self.loggedInUser?.uid) {
print("Same as logged in user, so don't show!")
} else {
if let locationValue = snapshot.value as? [String: AnyObject] {
let lat = Double(locationValue["businessLatitude"] as! String)
let long = Double(locationValue["businessLongitude"] as! String)
let businessLocation = CLLocation(latitude: lat!, longitude: long!)
let latitude = self.locationManager.location?.coordinate.latitude
let longitude = self.locationManager.location?.coordinate.longitude
let userLocation = CLLocation(latitude: latitude!, longitude: longitude!)
let distanceInMeters: Double = userLocation.distance(from: businessLocation)
let distanceInMiles: Double = distanceInMeters * 0.00062137
let distanceLabelText = String(format: "%.2f miles away", distanceInMiles)
var singleChildDictionary = locationValue
singleChildDictionary["distanceLabelText"] = distanceLabelText as AnyObject
singleChildDictionary["distanceInMiles"] = distanceInMiles as AnyObject
self.usersArray.append(singleChildDictionary as NSDictionary)
self.usersArray = self.usersArray.sorted {
!($0?["distanceInMiles"] as! Double > $1?["distanceInMiles"] as! Double)
}
}
//insert the rows
//self.followUsersTableView.insertRows(at: [IndexPath(row:self.usersArray.count-1,section:0)], with: UITableViewRowAnimation.automatic)
self.followUsersTableView.reloadData()
}
}) { (error) in
print(error.localizedDescription)
}
}
答案 0 :(得分:3)
致电locationManager.stopUpdatingLocation()
后,您立即致电locationManager.startUpdatingLocation()
。
这不会起作用,因为您需要留出时间来确定位置。在收到didUpdateLocations
委托方法的调用之前,您不应该使用位置。
如果您的目标是iOS 9及更高版本而您只需要一个位置,那么您应该调用requestLocation()
而不是startUpdatingLocation()
,但仍需要等待委托方法的回调。
收到位置后,您就可以加载表格数据了。