延时操作

延时操作

 dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        [self ad];
    });
   
    // repeats 传YES 会间隔1.5秒继续调用ad方法
    [NSTimer scheduledTimerWithTimeInterval:1.5 target:self selector:@selector(ad) userInfo:nil repeats:NO];
   
    [self performSelector:@selector(ad) withObject:nil afterDelay:1.5];