/** 定時器(這里不用帶*，因為dispatch_source_t就是個類，內(nèi)部已經(jīng)包含了*) */

@property?(nonatomic,?strong)?dispatch_source_t?timer;

int?count?=?0;

-?(void)touchesBegan:(NSSet?*)touches?withEvent:(UIEvent?*)event

{

//?獲得隊列

//????dispatch_queue_t?queue?=?dispatch_get_global_queue(0,?0);

dispatch_queue_t?queue?=?dispatch_get_main_queue();

//?創(chuàng)建一個定時器(dispatch_source_t本質(zhì)還是個OC對象)

self.timer?=?dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER,?0,?0,?queue);

//?設(shè)置定時器的各種屬性（幾時開始任務，每隔多長時間執(zhí)行一次）

//?GCD的時間參數(shù)，一般是納秒?NSEC_PER_SEC（1秒?==?10的9次方納秒）

//?何時開始執(zhí)行第一個任務

//?dispatch_time(DISPATCH_TIME_NOW,?3.0?*?NSEC_PER_SEC)?比當前時間晚3秒

dispatch_time_t?start?=?dispatch_time(DISPATCH_TIME_NOW,?(int64_t)(1.0?*?NSEC_PER_SEC));

uint64_t?interval?=?(uint64_t)(1.0?*?NSEC_PER_SEC);

dispatch_source_set_timer(self.timer,?start,?interval,?0);

//?設(shè)置回調(diào)

dispatch_source_set_event_handler(self.timer,?^{

NSLog(@"------------%@",?[NSThread?currentThread]);

count++;

//????????if?(count?==?4)?{

//????????????//?取消定時器

//????????????dispatch_cancel(self.timer);

//????????????self.timer?=?nil;

//????????}

});

//?啟動定時器

dispatch_resume(self.timer);