UIScrollView引导页翻页效果

利用UIScrollView制作一个类似于Appstroe中应用介绍详情里面点击图片放大的引导页，直接上代码

效果图如下

ViewController.h
@interface ViewController : UIViewController<UIScrollViewDelegate>
//滚动视图对象
@property (retain, nonatomic) UIScrollView *scrollView;
//视图中小圆点，对应视图的页码
@property (retain, nonatomic) UIPageControl *pageControl;
//动态数组对象，存储图片
@property (retain, nonatomic) NSMutableArray *images;
@end

ViewController.m
#import "ViewController.h"

#define SCREEN_WIDTH ([UIScreen mainScreen].bounds.size.width)
#define SCREEN_HEIGHT ([UIScreen mainScreen].bounds.size.height)

#define imgHeight SCREEN_HEIGHT - 160
#define imgWidth SCREEN_WIDTH - 65

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //初始化数组，存储滚动视图的图片
    self.images = [NSMutableArray arrayWithObjects:[UIImage imageNamed:@"text1.png"],[UIImage imageNamed:@"text2.png"],[UIImage imageNamed:@"text3.png"],[UIImage imageNamed:@"text4.png"], nil];
    //设置视图的背景颜色
    self.view.backgroundColor = [UIColor whiteColor];
    [self initScrollView];
}

-(void)initScrollView{
//初始化滚动视图
//注意此处scrollView的宽度，如果不想每次翻页都滚动一个屏幕的宽度，需要自己设置一般是图片宽度加间隙
    self.scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 106.5, imgWidth + 19.5, imgHeight)];
//设置按页滚动
    self.scrollView.pagingEnabled = YES;
//隐藏滚动条
    self.scrollView.showsHorizontalScrollIndicator = NO;
//设置滚动的范围
    self.scrollView.contentSize = CGSizeMake(self.images.count * (imgWidth + 19.5), 0);
//设置为NO时可以显示超出scrollView的部分
    self.scrollView.clipsToBounds = NO;
  //设置代理
    self.scrollView.delegate = self;
//设置初始偏移量
    self.scrollView.contentOffset = CGPointMake(0, 0);
    [self.view addSubview:self.scrollView];
    //添加图片
    for (int i = 0; i<self.images.count; i++) {
        CGFloat x = 32.5 + i * (imgWidth + 19.5);
        CGRect frame = CGRectMake(x, 0, imgWidth, imgHeight);
        UIImageView *photoV = [[UIImageView alloc] initWithFrame:frame];
        photoV.image = [self.images objectAtIndex:i];
        [self.scrollView addSubview:photoV];
        
    }
    //设置底部页数指示标志
    _pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(0, SCREEN_HEIGHT - 50, SCREEN_WIDTH, 20)];
    _pageControl.numberOfPages = self.images.count;
    _pageControl.currentPageIndicatorTintColor = [UIColor blueColor];
    _pageControl.pageIndicatorTintColor = [UIColor lightGrayColor];
    _pageControl.userInteractionEnabled = YES;
    _pageControl.currentPage = 0;
//添加点击事件
     [_pageControl addTarget:self action:@selector(changePage:) forControlEvents:UIControlEventValueChanged];
    [self.view addSubview:_pageControl];
}

//改变页码的方法实现
- (void)changePage:(id)sender
{
    NSLog(@"指示器的当前索引值为:%li",(long)self.pageControl.currentPage);
    [self.scrollView setContentOffset:CGPointMake(self.pageControl.currentPage * self.scrollView.frame.size.width, 0) animated:YES];
}

//下面两种协议只需实现一种
#pragma mark-----UIScrollViewDelegate---------
//实现协议UIScrollViewDelegate的方法
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
//根据scrolView的左右滑动,对pageCotrol的当前指示器进行切换(设置currentPage)
    int pageNum = scrollView.contentOffset.x / self.scrollView.frame.size.width;
    //切换改变页码，小圆点
    self.pageControl.currentPage = pageNum;
}
//最好采用下面这种方法，上面那种方法只有在滚动停止时调用，当滚动很快时，中间过程就没有显示小圆点的变化，只是显示了最后停止时的位置
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    self.pageControl.currentPage =   _scrollView.contentOffset.x / _scrollView.frame.size.width;
}

项目代码：
https://git.oschina.net/iOSlwg/ScrollViewdemo/tree/master/