scrollView ——自动轮播并且设置图片底部小圆点

#import "ScrollViewController.h"#import "Global.h"#define ScrollViewHeight (SCREENHEIGHT - 100)@interface ScrollViewController ()@property (nonatomic, strong) UIScrollView *scrollView;@property (nonatomic, strong) UILabel *label;@property (nonatomic, strong) UIPageControl *pageControl;@property (nonatomic, strong) NSTimer *timer;@end@implementation ScrollViewController- (void)viewDidLoad{    [super viewDidLoad];                [self initView];}- (void)initView{        //设置滚动视图的主体    _scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, SCREENWIDTH, ScrollViewHeight)];        _scrollView.pagingEnabled = YES;    _scrollView.bounces = NO;        _scrollView.delegate = self;        for (int i = 1; i < 5; ++i)    {                UIImageView *imageView = [[UIImageView alloc] initWithFrame: CGRectMake(0, (i - 1) * ScrollViewHeight, SCREENWIDTH, ScrollViewHeight)];                imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%d.jpg", i]];        [_scrollView addSubview:imageView];    }        //设置第五张图片和第一张图片相同        UIImageView *imageView = [[UIImageView alloc] initWithFrame: CGRectMake(0, 4 * ScrollViewHeight, SCREENWIDTH, ScrollViewHeight)];        imageView.image = [UIImage imageNamed:@"1.jpg"];    [_scrollView addSubview:imageView];        _scrollView.contentSize = CGSizeMake(SCREENWIDTH, ScrollViewHeight * 5);        [self.view addSubview:_scrollView];        //设置时钟    _timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(changeView) userInfo:nil repeats:YES];        //设置底部文字    _label = [[UILabel alloc] initWithFrame:CGRectMake(SCREENWIDTH / 2 - 50, ScrollViewHeight, SCREENWIDTH, 50)];    _label.textColor = [UIColor whiteColor];    _label.text = @"这是第1页";    [self.view addSubview:_label];        //设置视图上的小圆点    _pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(0, ScrollViewHeight - 50, SCREENWIDTH, 30)];    _pageControl.numberOfPages = 4;    _pageControl.currentPage = 0;        [_pageControl addTarget:self action:@selector(pageTurn:) forControlEvents:UIControlEventValueChanged];        [self.view addSubview:_pageControl];}//设置时钟调用的方法- (void)changeView{    float resultPiontY = 0.0;    //这里获取的信息是未翻页前的信息。        //当前的点不在最后一页的时候，每次正常翻页，当是最后一页的时候，把最后一页变为第一页（小圆点当前页数设置为1，当前点设置为0.0）    //注意：当前的计算点是下一页的点，当前计算的页数是下一页的页数    int i = 1;    if (_scrollView.contentOffset.y < 3 * ScrollViewHeight)    {        i = _scrollView.contentOffset.y / (SCREENHEIGHT - 100) + 1;    }    else if (_scrollView.contentOffset.y == 3 *ScrollViewHeight)    {        i = 0;    }    else    {        _scrollView.contentOffset = CGPointMake(0, 0);    }            _label.text = [NSString stringWithFormat:@"这是第%d页", i + 1];        _pageControl.currentPage = i;        resultPiontY = _scrollView.contentOffset.y + ScrollViewHeight;        [_scrollView setContentOffset:CGPointMake(0, resultPiontY) animated:YES];}//设置小圆点点击方法- (void)pageTurn:(UIPageControl *)sender{        [_scrollView setContentOffset:CGPointMake(0, sender.currentPage * _scrollView.frame.size.height) animated:YES];}//当开始拖拽的时候停止时钟- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{    [_timer setFireDate:[NSDate distantFuture]];}//当结束拖拽时执行的方法，- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{    _label.text = [NSString stringWithFormat:@"这是第%d页", (int)(scrollView.contentOffset.y / (SCREENHEIGHT - 100)) + 1];        }//当结束滚当时执行的方法，变更页数，并且在5秒后开始时钟- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{    //这里获取的信息是已经翻过页的信息    int i = 0;    if (_scrollView.contentOffset.y < 4 * ScrollViewHeight)    {        i = scrollView.contentOffset.y / (SCREENHEIGHT - 100);    }    else    {        _scrollView.contentOffset = CGPointMake(0, 0);        i = 0;    }        _label.text = [NSString stringWithFormat:@"这是第%d页", i + 1];        _pageControl.currentPage = i;        [_timer setFireDate:[NSDate dateWithTimeInterval:5.0 sinceDate:[NSDate date]]];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}/*#pragma mark - Navigation// In a storyboard-based application, you will often want to do a little preparation before navigation- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {    // Get the new view controller using [segue destinationViewController].    // Pass the selected object to the new view controller.}*/@end