如何使用Objective C在Scroll视图中引入图像之间的延迟？

Question

    if(self){
        UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0,0, self.view.frame.size.width, self.view.frame.size.height)];
        scrollView.contentSize = CGSizeMake(320, 465);

        [scrollView setScrollEnabled:YES];
        [scrollView setPagingEnabled:YES];
        [scrollView setAlwaysBounceVertical:NO];
        [self.uiSubView addSubview:scrollView];

        NSMutableArray *arrImage = [NSMutableArray arrayWithObjects:@"a.jpeg", @"cat.jpg", @"s.jpeg",@"ss.jpeg", nil];

        for (int i = 0; i < [arrImage count]; i++)
        {
            CGFloat xOrigin = i * scrollView.frame.size.width;


            UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(xOrigin, 0, scrollView.frame.size.width, scrollView.frame.size.height)];
            [imageView setImage:[UIImage imageNamed:[arrImage objectAtIndex:i]]];
            [imageView setContentMode:  UIViewContentModeScaleAspectFit];

            [scrollView addSubview:imageView];


        }

        [scrollView setContentSize:CGSizeMake(scrollView.frame.size.width * [arrImage count], scrollView.frame.size.height)];


    }


 [NSTimer scheduledTimerWithTimeInterval:2.0
                                     target:self
                                   selector:@selector(scrollPages)
                                   userInfo:nil
                                    repeats:NO];




- (void)scrollPages
{
//I want a method here,  the timer works for the first image later it  will not scroll, so tel me how to introduce delay between images.

}

Answer 1

在viewWillAppear:

中添加定时器调用

_slideShowTimer = [NSTimer scheduledTimerWithTimeInterval:K_DEFINE_YOUR_TIME
                                  target:self
                                selector:@selector(scrollPages)
                                userInfo:Nil
                                 repeats:YES];


-(void)scrollPages {

    if (currentPage>=self.pageControl.numberOfPages) {
        currentPage=0;
        [self.scrollView setContentOffset:CGPointMake(0, 0) animated:YES];
    }
    [self scrollToPage:currentPage];
    currentPage++;
}

-(void)scrollToPage:(NSInteger)aPage {

    float myPageWidth = [self.scrollView frame].size.width;
    [self.scrollView setContentOffset:CGPointMake(aPage*myPageWidth,0) animated:YES];
}

- (void)scrollViewDidScroll:(UIScrollView *)sender {
     // Update the page when more than 50% of the previous/next page is visible
    if (!pageControlBeingUsed) {
        CGFloat pageWidth = self.scrollView.frame.size.width;
        pageNumber = floor((self.scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
        self.pageControl.currentPage = pageNumber;
    }
}


- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
    pageControlBeingUsed = NO;
    pageNumber1 = pageNumber;

}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {

    pageControlBeingUsed = NO;
    pageNumber2 = pageNumber;

    if(pageNumber == 4 && pageNumber2 == pageNumber1){
    //Do any action you want to do from last page or you add by your condition.

    }
}

Answer 2

-(void)scrollPages
{
    int currentPage = (int)self.scrollView.contentOffset.x / self.scrollView.bounds.size.width;
    int totalPages = (int)self.scrollView.contentSize.width / self.scrollView.bounds.size.width;
    if(currentPage < totalPages)
    {
        currentPage++;
    }
    else
    {
        currentPage = 1;
    }
    [self.scrollView setContentOffset:CGPointMake((currentPage-1)*self.scrollView.bounds.size.width,0)];
}

还启用分页。