使用UIScrollView 实现分页功能

 

首先找8张jpg的图片，将它的名字分别设置为01.png......08.jpg,然后将代码运行，就可看见效果

- (void)viewDidLoad

{

    [superviewDidLoad];

    _scrollView = [[UIScrollViewalloc]init];

    //设置scrollview的可视范围

    _scrollView.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);

    //1.创建UIImageView用来显示在UIScrollView上

        CGFloat w = self.view.frame.size.width;

    CGFloat h = self.view.frame.size.height;

    for (int i = 0; i < 9; i++) {

        NSString *imageName = [NSStringstringWithFormat:@"0%d.jpg",i+1];

        UIImage *image = [UIImage imageNamed:imageName];

        UIImageView *imageView = [[UIImageViewalloc]initWithImage:image];

        //2.设置imageview的frame

        imageView.frame = CGRectMake(i * w, 0, w, h);

        [_scrollView addSubview:imageView];

    }

    //3.设置scrollview的内容尺寸

    _scrollView.contentSize = CGSizeMake(w * 8, 0);

    _scrollView.delegate = self;

    _scrollView.pagingEnabled = YES;

          [self.viewaddSubview:_scrollView];

    //4.添加pagecontrol

    UIPageControl *pageControl = [[UIPageControlalloc]init];

    pageControl.currentPageIndicatorTintColor = [UIColorredColor];

    pageControl.pageIndicatorTintColor = [UIColorblackColor];

    pageControl.center = CGPointMake(160, 440);

    pageControl.bounds = CGRectMake(0, 0, 80, 20);

    //5.如果不设置总页数，那么就不会显示pagecontrol

    pageControl.numberOfPages = 8;

    //6.禁止默认的点击功能

    pageControl.enabled = NO;

    [self.view addSubview:pageControl];

    _pageControl = pageControl;

} 

#pragma mark - scrollview的代理方法，此方法在拖动scrollview时就会调用

- (void)scrollViewDidScroll:(UIScrollView *)scrollView

{

    //7.设置pagecontrol的当前值，它的当前值也就是scrollview的contentoffset的x除以scrollview的宽度，

    int page = _scrollView.contentOffset.x / scrollView.frame.size.width;

    _pageControl.currentPage = page;

}