//倒計時時間
__block int timeout= 2;?
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); //每秒執(zhí)行
dispatch_source_set_event_handler(_timer, ^{
if(timeout<=0){ //倒計時結(jié)束，關(guān)閉
dispatch_source_cancel(_timer);
dispatch_async(dispatch_get_main_queue(), ^{
//倒計時結(jié)束，開始設(shè)置操作
aButton.userInteractionEnabled = YES;
});
}else{
//? ? ? ? ? ? int minutes = timeout / 60;
//? ? ? ? ? ? int seconds = timeout % 60;
//? ? ? ? ? ? NSString *strTime = [NSString stringWithFormat:@"%d分%.2d秒后重新獲取驗證碼",minutes, seconds];
dispatch_async(dispatch_get_main_queue(), ^{
//開始倒計時，設(shè)置倒計時顯示
aButton.userInteractionEnabled = NO;
});
timeout--;
}
});
dispatch_resume(_timer);
