ios中如何让程序的定时器在程序进入后台的时候依然继续有效?
只需添加以下代码到中applicationDidEnterBackground(application: UIApplication)
func applicationDidEnterBackground(application: UIApplication) {
application.beginReceivingRemoteControlEvents()
var bgTask : UIBackgroundTaskIdentifier?
bgTask = application.beginBackgroundTaskWithExpirationHandler {
dispatch_async(dispatch_get_main_queue(), {
if bgTask != UIBackgroundTaskInvalid
{
bgTask = UIBackgroundTaskInvalid
}
})
}
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
dispatch_async(dispatch_get_main_queue(), {
if bgTask != UIBackgroundTaskInvalid
{
bgTask = UIBackgroundTaskInvalid
}
})
}
}
真机iPhone4s测试过十分钟和三十分钟都没有问题
