iOS延时执行的几种方式,附带GCD写的定时器

一.延时执行的几种方式

最近发现扫描宝挺好用,将手写的几种延时方式发出来分享一下:

二.GCD写的定时器

- (void)startTimerWithDelay:(NSInteger)delayTime passOneSeconds:(void(^)(int currentTime))oneSecondsPassBlock stop:(void(^)())stopBlock{

倒计时时间自定

__block int timeout = delayTime;

dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

dispatch_source_t _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue);

dispatch_source_set_timer(_timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒执行

dispatch_source_set_event_handler(_timer, ^{

if(timeout <= 0){ //倒计时结束，关闭

dispatch_source_cancel(_timer);

dispatch_async(dispatch_get_main_queue(), ^{

//这里调用结束的Blcok

if(stopBlock){

stopBlock();

}

});

}else{

dispatch_async(dispatch_get_main_queue(), ^{

//倒计时中,每过一秒调用过去1s的block

if(oneSecondsPassBlock){

oneSecondsPassBlock(timeout);

}

});

timeout--;

}

});

dispatch_resume(_timer);

}