private var timer: dispatch_source_t? = nil@H_403_9@

private func startTimer() {@H_403_9@

let updateInterval: UInt64 = 1@H_403_9@

let interval = updateInterval * NSEC_PER_SEC@H_403_9@

let leeway: UInt64 = 300000000 // UInt64(0.3) * interval@H_403_9@

let queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,0)@H_403_9@

@H_403_9@

timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER,0,queue)@H_403_9@

if timer != nil {@H_403_9@

dispatch_source_set_timer(timer!,dispatch_walltime(nil,0),interval,leeway)@H_403_9@

dispatch_source_set_event_handler(timer!,{ () -> Void in@H_403_9@

self.checkNewScreenshot()@H_403_9@

})@H_403_9@

}@H_403_9@

dispatch_resume(timer!)@H_403_9@

}@H_403_9@

@H_403_9@

private func stopTimer() {@H_403_9@

if timer != nil {@H_403_9@

dispatch_suspend(timer!)@H_403_9@

dispatch_resume(timer!)@H_403_9@

timer = nil@H_403_9@

}@H_403_9@

}@H_403_9@ 原文链接：https://www.f2er.com/swift/325402.html