NSTimer

- (void)someAction
{
	NSTimeInterval timeInterval = 0.5;
	NSTimer *showTimer = [NSTimer scheduledTimerWithTimeInterval:timeInterval target:self selector:@selector(timerTest:) userInfo:nil repeats:NO];
}
-(void)timerTest:(NSTimer *)theTimer
{
    UIAlertView *timerAlert = [[UIAlertView alloc]initWithTitle:@"timer test!" message:nil delegate:self cancelButtonTitle:@"ok" otherButtonTitles:nil, nil];
    [timerAlert show];
    [theTimer  invalidate];
}

-(void)someAction
{  
    testView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 1024, 768)];  
    testView.backgroundColor = [UIColor clearColor];  
    testView.userInteractionEnabled = YES;  
    [self.view addSubview:testView];  

    [someThing reloadData];  
    [NSTimer scheduledTimerWithTimeInterval:1.5f target:self selector:@selector(timerTest:) userInfo:nil repeats:NO];  
}  
- (void)timerTest:(NSTimer*)theTimer  
{  
    [testView removeFromSuperview];  
}