AJ分享，必須精品 ### 先看效果    ### 代碼 ~~~ #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 //懶加載加載scrollView -(UIScrollView *)scrollView { if (_scrollView == nil) { _scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(10, 20, 300, 130)]; _scrollView.backgroundColor = [UIColor redColor]; [self.view addSubview:_scrollView]; //contentSize //高度為0 只水平滾動 self.scrollView.contentSize = CGSizeMake(kImageCount * _scrollView.bounds.size.width, 0); //取消彈簧效果 _scrollView.bounces = NO; //取消滾動條 _scrollView.showsHorizontalScrollIndicator = NO;//水平 _scrollView.showsVerticalScrollIndicator = NO;//豎直 //要分頁 _scrollView.pagingEnabled = YES; //設置代理 _scrollView.delegate = self; } return _scrollView; } -(UIPageControl *)pageControl { if (_pageControl == nil) { //分頁控件，本質上和scrollView沒有任何關系，是兩個獨立的控件 _pageControl = [[UIPageControl alloc]init]; //總頁數 _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); //設置顏色 _pageControl.pageIndicatorTintColor = [UIColor redColor]; _pageControl.currentPageIndicatorTintColor = [UIColor blackColor]; [self.view addSubview:_pageControl]; //添加監聽方法 /**在OC中，絕大多數“繼承UIControl控件”，都可以監聽UIControlEventValueChanged事件，只有button除外，button是點得，是touchup。。。*/ [_pageControl addTarget:self action:@selector(pageChanged:) forControlEvents:UIControlEventValueChanged]; } return _pageControl; } //分頁控件的監聽方法 -(void)pageChanged:(UIPageControl *)page { //根據頁數，調整滾動視圖中得圖片位置contentOffset CGFloat x = page.currentPage * self.scrollView.bounds.size.width; [self.scrollView setContentOffset:CGPointMake(x, 0) animated:YES]; } - (void)viewDidLoad { [super viewDidLoad]; //設置圖片 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]; } //計算imageView的位置 [self.scrollView.subviews enumerateObjectsUsingBlock:^(UIImageView *imageView, NSUInteger idx, BOOL *stop) { //調整x =》 origin =》frame CGRect frame = imageView.frame; frame.origin.x = idx * frame.size.width; imageView.frame = frame; }]; //分頁初始頁數為0 self.pageControl.currentPage = 0; //啟動時鐘 [self startTimer]; } /**啟動時鐘*/ -(void)startTimer { self.timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(updateTimer) userInfo:nil repeats:YES]; //添加運行循環 [[NSRunLoop currentRunLoop]addTimer:self.timer forMode:NSRunLoopCommonModes]; } -(void)updateTimer { //頁號發生變化 //（當前頁數 + 1） % 總頁數 int page = (self.pageControl.currentPage+1) % kImageCount; self.pageControl.currentPage = page; //調用監聽方法。讓滾動視圖滾動 [self pageChanged:self.pageControl]; } #pragma mark - scrollView的代理方法 //滾動視圖停下來 -(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { // 停下來的當前頁數,通過contentOffset獲取當前偏移量 NSLog(@"%@",NSStringFromCGPoint(scrollView.contentOffset)); //計算頁數 int page = scrollView.contentOffset.x/scrollView.bounds.size.width; self.pageControl.currentPage = page; } /** 抓住圖片時，停止時鐘，松手后，開啟時鐘 */ -(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView { //停止時鐘，停止后就不能在使用，如果要啟用時鐘，需要重新實例化 [self.timer invalidate]; } -(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate { //啟動時鐘 [self startTimer]; } @end ~~~ ### 實現思路 1.scrollView getter方法懶加載 指定了大小，添加到視圖 2，viewDidLoad中添加圖像，并計算位置 3，運行觀察效果，修改scrollView的屬性…. 4，實例化UIPageControl 5，因為分頁控件與滾動視圖分離，因此監聽滾動停止代理方法，修改分頁控件的頁數 6，將UIPageControl定義成屬性，并且添加監聽方法。 7，實現監聽方法，頁數變化后，修改scrollView的位置 8，添加時鐘，調用分頁控件的監聽方法，實現圖片自動輪播 ? ?