iOS隐藏一个View（定时器）

三种定时器

 _view1 = [UIViewnew];

    [self.viewaddSubview:_view1];

    _view1.frame =CGRectMake(100,100,100, 100);

    _view1.backgroundColor = [UIColorredColor];

1.

[self performSelector:@selector(jideHUD) withObject:nil afterDelay:2.5];

 //afterDelay多少秒之后

- (void)jideHUD{

   // _view1.hidden = YES;

    _view1.alpha =0.0;

    

}

2.

    //定时器

    //repeats 重复。yes    NO，只周一次

    [NSTimerscheduledTimerWithTimeInterval:1.5target:selfselector:@selector(jideHUD)userInfo:nilrepeats:NO];

    NSLog(@"1212");

    

- (void)jideHUD{

     NSLog(@"12");

   // _view1.hidden = YES;

    _view1.alpha = 0.0;

    

}

3.

   多线程(2)GCD

    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{

        _view1.hidden = YES;                

    });