2018-05-25 更新:
在阅读 Rob 在这里的回答后，我将 datatask 替换为 downloadTask:https://stackoverflow.com/a/44140059/4666760。当应用程序处于后台时它仍然不起作用。
你好
我需要一些有关 iOS 后台任务的帮助。我想使用 Apple 推送通知服务 (APNs) 在后台唤醒我的应用程序，以便它可以对我的服务器执行简单的 RESTful API 调用。当应用程序在前台但不在后台时，我能够让它工作。我想我对 URLSession 的配置做错了什么，但我不知道。应用程序和服务器的完整代码位于下面链接的我的仓库中。请克隆它并做任何你喜欢的事情——我只需要你的帮助:)
https://github.com/knutvalen/ping
在 AppDelegate.swift 中，应用监听远程通知:
class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate {
// MARK: - Properties
var window: UIWindow?
// MARK: - Private functions
private func registerForPushNotifications() {
UNUserNotificationCenter.current().delegate = self
UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { (granted, error) in
guard granted else { return }
DispatchQueue.main.async {
UIApplication.shared.registerForRemoteNotifications()
}
}
}
// MARK: - Delegate functions
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
Login.shared.username = "foo"
registerForPushNotifications()
return true
}
func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
let tokenParts = deviceToken.map { data -> String in
return String(format: "%02.2hhx", data)
}
let token = tokenParts.joined()
os_log("AppDelegate application(_:didRegisterForRemoteNotificationsWithDeviceToken:) token: %@", token)
}
func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
os_log("AppDelegate application(_:didFailToRegisterForRemoteNotificationsWithError:) error: %@", error.localizedDescription)
}
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
os_log("AppDelegate application(_:didReceiveRemoteNotification:fetchCompletionHandler:)")
if let aps = userInfo["aps"] as? [String: AnyObject] {
if aps["content-available"] as? Int == 1 {
RestController.shared.onPing = { () in
RestController.shared.onPing = nil
completionHandler(.newData)
os_log("AppDelegate onPing")
}
RestController.shared.pingBackground(login: Login.shared)
// RestController.shared.pingForeground(login: Login.shared)
}
}
}
func application(_ application: UIApplication, handleEventsForBackgroundURLSession identifier: String, completionHandler: @escaping () -> Void) {
RestController.shared.backgroundSessionCompletionHandler = completionHandler
}
}
RestController.swift 处理具有后台配置的 URLSession:
class RestController: NSObject, URLSessionDelegate, URLSessionTaskDelegate, URLSessionDownloadDelegate {
// MARK: - Properties
static let shared = RestController()
let identifier = "no.qassql.ping.background"
let ip = "http://123.456.7.89:3000"
var backgroundUrlSession: URLSession?
var backgroundSessionCompletionHandler: (() -> Void)?
var onPing: (() -> ())?
// MARK: - Initialization
override init() {
super.init()
let configuration = URLSessionConfiguration.background(withIdentifier: identifier)
configuration.isDiscretionary = false
configuration.sessionSendsLaunchEvents = true
backgroundUrlSession = URLSession(configuration: configuration, delegate: self, delegateQueue: nil)
}
// MARK: - Delegate functions
func urlSessionDidFinishEvents(forBackgroundURLSession session: URLSession) {
DispatchQueue.main.async {
if let completionHandler = self.backgroundSessionCompletionHandler {
self.backgroundSessionCompletionHandler = nil
completionHandler()
}
}
}
func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
if let error = error {
os_log("RestController urlSession(_:task:didCompleteWithError:) error: %@", error.localizedDescription)
}
}
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
do {
let data = try Data(contentsOf: location)
let respopnse = downloadTask.response
let error = downloadTask.error
self.completionHandler(data: data, response: respopnse, error: error)
} catch {
os_log("RestController urlSession(_:downloadTask:didFinishDownloadingTo:) error: %@", error.localizedDescription)
}
}
// MARK: - Private functions
private func completionHandler(data: Data?, response: URLResponse?, error: Error?) {
guard let data = data else { return }
if let okResponse = OkResponse.deSerialize(data: data) {
if okResponse.message == ("ping_" + Login.shared.username) {
RestController.shared.onPing?()
}
}
}
// MARK: - Public functions
func pingBackground(login: Login) {
guard let url = URL(string: ip + "/ping") else { return }
var request = URLRequest(url: url, cachePolicy: .reloadIgnoringCacheData, timeoutInterval: 20)
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpMethod = "POST"
request.httpBody = login.serialize()
if let backgroundUrlSession = backgroundUrlSession {
backgroundUrlSession.downloadTask(with: request).resume()
}
}
func pingForeground(login: Login) {
guard let url = URL(string: ip + "/ping") else { return }
var request = URLRequest(url: url)
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpMethod = "POST"
request.httpBody = login.serialize()
URLSession.shared.dataTask(with: request) { (data, response, error) in
return self.completionHandler(data: data, response: response, error: error)
}.resume()
}
}
最佳答案
通过在 info.plist 中添加 App provides Voice over IP services 作为 Required Background Mode 并使用 PushKit 处理 APNs 有效载荷，我能够做我想做的事。 SSCCE(示例)在我的存储库中可用:
关于ios - 来自 iOS 后台 URLSession 使用 APNs 的 REST 请求，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50497207/