This is an updated Swift version of the example of the Infinite Running Background Task written in Objective C http://hayageek.com/ios-long-running-background-task/ Infinite task is based on playing blank audio file. My version is simplified to a minumum to run the task forever in the background. I also included a blank wav file that will be played forever until you stop the task. *Note: Battery consuming is 10% for 24 hours period.
#YouTube tutorial and overview https://www.youtube.com/watch?v=j7b35lFcMqM
Copy manually file BackgroundTask.swift into your project.
#Warning Do NOT attemp to use my implementation if you are planning to push your app to the App Store. Apple will 100% reject such behavior. This project was designed for research purposes or personal use.
var backgroundTask = BackgroundTask()
//Start playing blank audio file.
//You can run NSTimer() or whatever you need and it will continue executing in the background.
backgroundTask.startBackgroundTask()
//Stop the task when you don't need it
backgroundTask.stopBackgroundTask()