AJ分享，必须精品 ### 先看效果    ### 代码 ~~~ #import "NYViewController.h" #define kImageCount 5 @interface NYViewController () <UIScrollViewDelegate> @property (nonatomic, strong) UIScrollView *scrollView; @property (nonatomic, strong) UIPageControl *pageControl; @property (nonatomic, strong) NSTimer *timer; @end @implementation NYViewController //懒加载加载scrollView -(UIScrollView *)scrollView { if (_scrollView == nil) { _scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(10, 20, 300, 130)]; _scrollView.backgroundColor = [UIColor redColor]; [self.view addSubview:_scrollView]; //contentSize //高度为0 只水平滚动 self.scrollView.contentSize = CGSizeMake(kImageCount * _scrollView.bounds.size.width, 0); //取消弹簧效果 _scrollView.bounces = NO; //取消滚动条 _scrollView.showsHorizontalScrollIndicator = NO;//水平 _scrollView.showsVerticalScrollIndicator = NO;//竖直 //要分页 _scrollView.pagingEnabled = YES; //设置代理 _scrollView.delegate = self; } return _scrollView; } -(UIPageControl *)pageControl { if (_pageControl == nil) { //分页控件，本质上和scrollView没有任何关系，是两个独立的控件 _pageControl = [[UIPageControl alloc]init]; //总页数 _pageControl.numberOfPages = kImageCount; //控件尺寸 CGSize size = [_pageControl sizeForNumberOfPages:kImageCount]; _pageControl.bounds = CGRectMake(0, 0, size.width, size.height); _pageControl.center = CGPointMake(self.view.center.x, 130); //设置颜色 _pageControl.pageIndicatorTintColor = [UIColor redColor]; _pageControl.currentPageIndicatorTintColor = [UIColor blackColor]; [self.view addSubview:_pageControl]; //添加监听方法 /**在OC中，绝大多数“继承UIControl控件”，都可以监听UIControlEventValueChanged事件，只有button除外，button是点得，是touchup。。。*/ [_pageControl addTarget:self action:@selector(pageChanged:) forControlEvents:UIControlEventValueChanged]; } return _pageControl; } //分页控件的监听方法 -(void)pageChanged:(UIPageControl *)page { //根据页数，调整滚动视图中得图片位置contentOffset CGFloat x = page.currentPage * self.scrollView.bounds.size.width; [self.scrollView setContentOffset:CGPointMake(x, 0) animated:YES]; } - (void)viewDidLoad { [super viewDidLoad]; //设置图片 for (int i = 0; i<kImageCount; i++) { NSString *imageName = [NSString stringWithFormat:@"img_%02d", i+1 ]; UIImage *image = [UIImage imageNamed:imageName]; UIImageView *imageView = [[UIImageView alloc] initWithFrame: self.scrollView.bounds]; imageView.image = image; [self.scrollView addSubview:imageView]; } //计算imageView的位置 [self.scrollView.subviews enumerateObjectsUsingBlock:^(UIImageView *imageView, NSUInteger idx, BOOL *stop) { //调整x =》 origin =》frame CGRect frame = imageView.frame; frame.origin.x = idx * frame.size.width; imageView.frame = frame; }]; //分页初始页数为0 self.pageControl.currentPage = 0; //启动时钟 [self startTimer]; } /**启动时钟*/ -(void)startTimer { self.timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(updateTimer) userInfo:nil repeats:YES]; //添加运行循环 [[NSRunLoop currentRunLoop]addTimer:self.timer forMode:NSRunLoopCommonModes]; } -(void)updateTimer { //页号发生变化 //（当前页数 + 1） % 总页数 int page = (self.pageControl.currentPage+1) % kImageCount; self.pageControl.currentPage = page; //调用监听方法。让滚动视图滚动 [self pageChanged:self.pageControl]; } #pragma mark - scrollView的代理方法 //滚动视图停下来 -(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { // 停下来的当前页数,通过contentOffset获取当前偏移量 NSLog(@"%@",NSStringFromCGPoint(scrollView.contentOffset)); //计算页数 int page = scrollView.contentOffset.x/scrollView.bounds.size.width; self.pageControl.currentPage = page; } /** 抓住图片时，停止时钟，松手后，开启时钟 */ -(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView { //停止时钟，停止后就不能在使用，如果要启用时钟，需要重新实例化 [self.timer invalidate]; } -(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate { //启动时钟 [self startTimer]; } @end ~~~ ### 实现思路 1.scrollView getter方法懒加载 指定了大小，添加到视图 2，viewDidLoad中添加图像，并计算位置 3，运行观察效果，修改scrollView的属性…. 4，实例化UIPageControl 5，因为分页控件与滚动视图分离，因此监听滚动停止代理方法，修改分页控件的页数 6，将UIPageControl定义成属性，并且添加监听方法。 7，实现监听方法，页数变化后，修改scrollView的位置 8，添加时钟，调用分页控件的监听方法，实现图片自动轮播