Swift-如何调用函数的特定日期和时间

Question

即使应用程序未运行，我如何每天下午13:00之后运行功能

Answer 1

You should use background task if you want to run the function if your application is on the background, not closed. Such as:

var timer = NSTimer(timeInterval: Your nstimerinterval, target: self, selector: "someBackgroundTask:", userInfo: nil, repeats: true)

func someBackgroundTask(timer:NSTimer) {

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), { () -> Void in
        println("You can do background tasks here.")

        dispatch_async(dispatch_get_main_queue(), { () -> Void in
            println("If you want to update your UI, you should do it here.")

        })
    })
}

Answer 2

The best way to do this is with an NSTimer . Use something like:

var timer = NSTimer.scheduledTimerWithTimeInterval(interval, target: self, selector: "function_name", userInfo: nil, repeats: true)

to create a loop that runs a certain function whenever you want.