ios - バナー画像を横にスライド

Question

このコードを使用して、バナー画像を 1 つずつ読み込みます。

 NSArray *imagesArray;
 int photoCount;
 UIImageView *imageView;

-(void)setupImageView{
     photoCount = 0;
     [[NSArray alloc]initWithObjects:[UIImage imageNamed:@"imgA.png"] ,
                                     [UIImage imageNamed:@"imgB.png"] ,
                                     [UIImage imageNamed:@"imgC.png"] ,
                                     [UIImage imageNamed:@"imgD.png"] ,
                                     [UIImage imageNamed:@"imgE.png"] , 
                                     nil];
     imageView =[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, width, height)];
     imageView.image = [imagesArray objectAtIndex:photoCount];
     [self.view addSubview:imageView];
     [NSTimer scheduledTimerWithTimeInterval:20.0 target:self selector:@selector(transitionPhotos) userInfo:nil repeats:YES];
 }

-(void)transitionPhotos{
    if (photoCount < [imagesArray count] - 1){
        photoCount ++;
    }else{
        photoCount = 0;
    }
    [UIView transitionWithView:self.imageView
                  duration:2.0
                   options:UIViewAnimationOptionTransitionCrossDissolve
                animations:^{ imageView.image = [imagesArray objectAtIndex:photoCount]; }
                completion:NULL];    
}

しかし、しばらくしてから画像を次々と水平にスライドさせる必要があります。どうすればそれを達成できますか？