摘要：
1.GCD设置一个timer计时器- (void)awakeFromNib { __weak id weakSelf = self; double delayInSeconds = 0.25; _timer =dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,dispatch_get_main_queue()); dispatch_source_set_timer(_timer, dispatch_walltime(NULL, 0),(unsigned)(delayInSeconds * NSEC_PER_SEC),... 阅读全文
