UIScrollView和UIPageController

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];
    [self.window makeKeyAndVisible];

    //创建导航栏控制器
    UINavigationController* nav = [[UINavigationController alloc]initWithRootViewController:[[ViewController alloc]init]];

    //设置应用程序的根控制器
    self.window.rootViewController = nav;
    return YES;
}

#import "ViewController.h"

#define Width [UIScreen mainScreen].bounds.size.width
#define Heigth [UIScreen mainScreen].bounds.size.heigth

@interface ViewController ()<UIScrollViewDelegate>

@property (retain)UIScrollView* scrollView;
@property (retain)UIPageControl* pageControl;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    self.view.backgroundColor = [UIColor whiteColor];

    self.scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake((Width-320)/2, 65, 320, 480)];
    self.scrollView.backgroundColor = [UIColor cyanColor];
    [self.view addSubview:self.scrollView];

    //要设置代理⚠️
    self.scrollView.delegate=self;

    for (NSInteger i = 0; i < 4; i++) {
        UIImageView* imageView = [[UIImageView alloc]initWithFrame:CGRectMake(320*i, 0, 320, 480)];
        [self.scrollView addSubview:imageView];
        imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"美女0%ld.jpg",i+1]];
        //防止内容视图下滑
        self.automaticallyAdjustsScrollViewInsets = NO;
        //设置滚动范围
        self.scrollView.contentSize = CGSizeMake(320*4, 480);
        //取消反弹效果
        self.scrollView.bounces = NO;
        //隐藏水平方向的滑块
        self.scrollView.showsHorizontalScrollIndicator = NO;
        //设置分页显示
        self.scrollView.pagingEnabled = YES;

        //创建UIPaneControl对象
        self.pageControl = [[UIPageControl alloc]initWithFrame:CGRectMake((Width-100)/2, 450+64, 100, 30)];
        self.pageControl.backgroundColor = [UIColor clearColor];
        //设置总页数
        self.pageControl.numberOfPages = 4;
        //设置当前页
        self.pageControl.currentPage = 0;

        //让self.pageControl绑定事件
        [self.pageControl addTarget:self action:@selector(pageAction:) forControlEvents:UIControlEventValueChanged];
        [self.view addSubview:self.pageControl];
    }
    //左边按钮
    UIButton* leftBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    leftBtn.frame = CGRectMake(0, 0, 60, 30);
    leftBtn.backgroundColor = [UIColor grayColor];
    [leftBtn setTitle:@"上一页" forState:UIControlStateNormal];
    [leftBtn addTarget:self action:@selector(leftAction:) forControlEvents:UIControlEventTouchUpInside];
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithCustomView:leftBtn];
    //右边按钮
    UIButton* rightBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    rightBtn.frame = CGRectMake(0, 0, 60, 30);
    rightBtn.backgroundColor = [UIColor grayColor];
    [rightBtn setTitle:@"下一页" forState:UIControlStateNormal];
    [rightBtn addTarget:self action:@selector(rightAction:) forControlEvents:UIControlEventTouchUpInside];
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithCustomView:rightBtn];

}

-(void)leftAction:(UIBarButtonItem*)sender
{
    NSLog(@"上一页被点!!!!");
    NSInteger page = self.pageControl.currentPage;
    if (page > 0) {
        page--;
        [UIView animateWithDuration:0.5 animations:^{
            self.pageControl.currentPage = page;
            self.scrollView.contentOffset = CGPointMake(320*page, 0);
        }];
    }
}

-(void)rightAction:(UIBarButtonItem*)sender
{
    NSLog(@"下一页被点!!!!");
    NSInteger page = self.pageControl.currentPage;
    if (page < 3) {
        page++;
        [UIView animateWithDuration:0.5 animations:^{
            self.pageControl.currentPage = page;
            self.scrollView.contentOffset = CGPointMake(320*page, 0);
        }];
    }
}

-(void)pageAction:(UIPageControl*)page
{
    NSLog(@"%ld",(long)page.currentPage);
    [UIView animateWithDuration:0.5 animations:^{
        self.scrollView.contentOffset = CGPointMake(page.currentPage*320, 0);
    }];
}

#pragma mark-UIScrollViewDelegate
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    NSLog(@"hehe");
    //获取偏移量
    CGPoint point = scrollView.contentOffset;
    NSLog(@"%@",NSStringFromCGPoint(point));
    //计算出当前展示的是第几张照片
    NSInteger page = point.x/300;
    self.pageControl.currentPage = page;
}