[英]Send Location of User in Background Swift
我正在構建一個應用程序,用戶點擊一個按鈕,然后我們通過將他們的位置上傳到服務器來跟蹤他們 60 分鍾(或任何時間)。 目前我們正在使用“Did Update Locations”功能將用戶位置實時發送到 Firebase。
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
}
該系統可以工作,但它會向服務器發送垃圾郵件,每秒鍾向服務器發送一次用戶的位置。
這是太多的數據,我們只需要每 10-30 秒將用戶位置發送到服務器一次。
我們可以做些什么每 10-30 秒發送一次用戶位置?
class ViewController: UIViewController, CLLocationManagerDelegate {
private var locman = CLLocationManager()
private var startTime: Date? //An instance variable, will be used as a previous location time.
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
guard let loc = locations.last else { return }
let time = loc.timestamp
guard var startTime = startTime else {
self.startTime = time // Saving time of first location, so we could use it to compare later with second location time.
return //Returning from this function, as at this moment we don't have second location.
}
let elapsed = time.timeIntervalSince(startTime) // Calculating time interval between first and second (previously saved) locations timestamps.
if elapsed > 30 { //If time interval is more than 30 seconds
print("Upload updated location to server")
updateUser(location: loc) //user function which uploads user location or coordinate to server.
startTime = time //Changing our timestamp of previous location to timestamp of location we already uploaded.
}
}
import UIKit
import CoreLocation
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate,CLLocationManagerDelegate {
var window: UIWindow?
var locationManager = CLLocationManager()
var backgroundUpdateTask: UIBackgroundTaskIdentifier!
var bgtimer = Timer()
var latitude: Double = 0.0
var longitude: Double = 0.0
var current_time = NSDate().timeIntervalSince1970
var timer = Timer()
var f = 0
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
self.doBackgroundTask()
return true
}
func applicationWillResignActive(_ application: UIApplication) {
}
func applicationWillEnterForeground(_ application: UIApplication) {
print("Entering foreBackground")
}
func applicationDidBecomeActive(_ application: UIApplication) {
}
func applicationWillTerminate(_ application: UIApplication) {
}
func applicationDidEnterBackground(_ application: UIApplication) {
print("Entering Background")
// self.doBackgroundTask()
}
func doBackgroundTask() {
DispatchQueue.main.async {
self.beginBackgroundUpdateTask()
self.StartupdateLocation()
self.bgtimer = Timer.scheduledTimer(timeInterval:-1, target: self, selector: #selector(AppDelegate.bgtimer(_:)), userInfo: nil, repeats: true)
RunLoop.current.add(self.bgtimer, forMode: RunLoopMode.defaultRunLoopMode)
RunLoop.current.run()
self.endBackgroundUpdateTask()
}
}
func beginBackgroundUpdateTask() {
self.backgroundUpdateTask = UIApplication.shared.beginBackgroundTask(expirationHandler: {
self.endBackgroundUpdateTask()
})
}
func endBackgroundUpdateTask() {
UIApplication.shared.endBackgroundTask(self.backgroundUpdateTask)
self.backgroundUpdateTask = UIBackgroundTaskInvalid
}
func StartupdateLocation() {
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.distanceFilter = kCLDistanceFilterNone
locationManager.requestAlwaysAuthorization()
locationManager.allowsBackgroundLocationUpdates = true
locationManager.pausesLocationUpdatesAutomatically = false
locationManager.startUpdatingLocation()
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
print("Error while requesting new coordinates")
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let locValue:CLLocationCoordinate2D = manager.location!.coordinate
self.latitude = locValue.latitude
self.longitude = locValue.longitude
f+=1
print("New Coordinates: \(f) ")
print(self.latitude)
print(self.longitude)
}
@objc func bgtimer(_ timer:Timer!){
sleep(2)
/* if UIApplication.shared.applicationState == .active {
timer.invalidate()
}*/
self.updateLocation()
}
func updateLocation() {
self.locationManager.startUpdatingLocation()
self.locationManager.stopUpdatingLocation()
}}
我添加了睡眠功能來延遲調用位置並將信息發送到服務器
由於這在應用程序處於活動狀態並進入后台運行。 如果您只需要后台進程,請從 didFinishLaunchingWithOptions 中刪除或注釋函數 self.doBackgroundTask() 並在 applicationdidEnterBackground 中刪除 self.doBackgroundTask() 的注釋。 然后刪除函數 bgtimer() 中的注釋,因為一旦應用程序進入活動狀態,后台進程就必須停止。
應用程序在移至后台后通常會暫停(不再獲得 CPU 時間)。 您可以要求額外的后台時間,但系統只給您 3 分鍾。
只有非常有限的一類應用程序被允許在后台運行更長的時間。 地圖/GPS 應用程序是這些類別之一。 但是,您的應用程序不是地圖/GPS 應用程序,因此我懷疑 Apple 是否會批准它。
底線:我認為您運行位置查詢超過 3 分鍾可能不走運。
正如 Paulw11 指出的那樣,當設備移動很遠的距離時,您可以使用重要的位置更改服務來獲取位置更新。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.