在applicationWillTerminate中发送请求

Question

在我的应用程序中，当用户终止应用程序时，我需要向服务器发送一些指令。在applicationWillTerminate函数中，我尝试发送它，但是它从未发送到服务器。我尝试使用Alamofire和本机URLSession，但是它不起作用。有人知道我怎么发送吗？我用这个代码

                let request = "\(requestPrefix)setDriverOrderStatus"
    if let url = URL(string:request) {
        var parameters : [String : String] = [:]
        parameters["access_token"] = UserSession.accessToken
        parameters["driver_id"] = UserSession.userID
        parameters["status"] = status
        var req = URLRequest(url: url)
        req.httpMethod = HTTPMethod.put.rawValue
        do {
            req.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted)
        } catch let error {
            print(error.localizedDescription)
        }
        _ = URLSession.shared.dataTask(with: req, completionHandler: { data, response, error in
            guard error == nil else {
                print(error ?? "error")
                return
            }
            guard let data = data else {
                print("Data is empty")
                return
            }
            let json = try! JSONSerialization.jsonObject(with: data, options: [])
            print(json)
        }).resume
    }

Answer 1

对我applicationWillTerminate有用的一种解决方案是在函数的末尾添加睡眠，如下所示：

func applicationWillTerminate(_ application: UIApplication) {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    // Saves changes in the application's managed object context before the application terminates.

    // HERE YOU will make you HTTP request asynchronously
    self.postLogoutHistory()

    // 3 is the number of seconds in which you estimate your request 
    // will be finished before system terminate the app process

    sleep(3)

    print("applicationWillTerminate")

    // self.saveContext()
}