UIScrollView+UIPageControl

#import "MainViewController.h"
#define WIDTH self.view.frame.size.width
#define HEIGHT self.view.frame.size.height
@interface MainViewController ()<UIScrollViewDelegate>

@end

@implementation MainViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];

    // UIScrollView拓展了UIView滚动方面的功能,它是所有滚动视图的基类
    // UITableView,UITextView都继承于该类
    // 使用场景:单张大图(屏幕显示不下);内容太多(图文混排);滚动头条(图片);相册等
    UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, WIDTH, HEIGHT)];
    scrollView.backgroundColor = [UIColor brownColor];
    [self.view addSubview:scrollView];
    [scrollView release];
    // scrollView本身还默认拥有两个视图:横纵滚动条
    // 它主要专长于两个方面
    // 一.contentSize重要属性,它可以让scrollView滚动起来(当contentSize大于frame.size时)
    // 内容大小;滚动范围
    scrollView.contentSize = CGSizeMake(WIDTH * 12, HEIGHT);
    // 按页进行滚动(是否整屏翻动)
//    scrollView.pagingEnabled = YES;
    // 偏移量:视图左上角距离坐标原点的偏移量
    scrollView.contentOffset = CGPointMake(WIDTH, 0);
    // 二.自带缩放功能,可以指定缩放倍数
    // 要实现缩放,还需要实现Delegate,指定缩放的视图是谁
    // 设置代理人
    scrollView.delegate = self;
    scrollView.tag = 1000;
    // 下边这几行一加上,轮播图就不能手动滑动了
//    scrollView.minimumZoomScale = 0.5;  // 缩小的最小比例
//    scrollView.maximumZoomScale = 1.5;  // 放大的最大比例
//    scrollView.zoomScale = 0.5;         // 设置变化比例
//    scrollView.bouncesZoom = YES;       // 控制缩放的时候是否会反弹
    // scrollView.zooming = YES;        // 判断是否正在进行缩放反弹
    // returns YES if user in zoom gesture,,不是这么用的

    // 控制是否允许滚动 默认YES
    scrollView.scrollEnabled = YES;

    // 关掉边界回弹效果 默认是YES
    scrollView.bounces = NO;
    // 控制水平和垂直方向遇到边框是否反弹
    scrollView.alwaysBounceHorizontal = NO;
    scrollView.alwaysBounceVertical = NO;
    // 水平和垂直的滚动条会作为两个子视图添加到scrollView的子视图里,如果把滚动条效果关闭,这两个视图就不会添加到scrollView的子视图里
//        NSLog(@"%@", scrollView.subviews);
    // 关闭滚动条
    scrollView.showsHorizontalScrollIndicator = NO; // 水平的
    scrollView.showsVerticalScrollIndicator = NO;   // 垂直的
    // 滑动到顶部(点状态条的时候)
    scrollView.scrollsToTop = YES;

    NSString *picNameStart = [NSString stringWithFormat:@"cymbal_09.jpg"];
    UIImageView *imageViewStart = [[UIImageView alloc] initWithImage:[UIImage imageNamed:picNameStart]];
    imageViewStart.frame = CGRectMake(0, 0, WIDTH, HEIGHT);
    [scrollView addSubview:imageViewStart];
    [imageViewStart release];

    for (NSInteger i = 0; i < 10; i++) {
        NSString *picName = [NSString stringWithFormat:@"cymbal_0%ld.jpg", i];
        // 通过图片名来创建UIImageView
        UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:picName]];

        imageView.frame = CGRectMake(WIDTH * (i + 1), 0, WIDTH, HEIGHT);
        //
        [scrollView addSubview:imageView];
        [imageView release];
    }

    NSString *picNameLast = [NSString stringWithFormat:@"cymbal_00.jpg"];
    UIImageView *imageViewLast = [[UIImageView alloc] initWithImage:[UIImage imageNamed:picNameLast]];
    imageViewLast.frame = CGRectMake(11 * WIDTH, 0, WIDTH, HEIGHT);
    [scrollView addSubview:imageViewLast];
    [imageViewLast release];

    // 创建一个计时器
//    [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(changeImage) userInfo:nil repeats:YES];
    // Do any additional setup after loading the view.
}

- (void)changeImage
{
    // 通过tag值找scrollView
    UIScrollView *scrollView = (UIScrollView *)[self.view viewWithTag:1000];
    scrollView.contentOffset = CGPointMake(scrollView.contentOffset.x + WIDTH, 0);
    // 带动画效果的,在这里反而效果差.
//    [scrollView setContentOffset:CGPointMake(scrollView.contentOffset.x + WIDTH, 0) animated:YES];
    if (scrollView.contentOffset.x == 11 * WIDTH) {
        scrollView.contentOffset = CGPointMake(WIDTH, 0);
    }
}

#pragma mark UIScrollView滚动的一些代理方法
// 只要滚动就会触发协议方法
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    NSLog(@"开始滚动");
}

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    NSLog(@"开始拖拽时触发");
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
    NSLog(@"结束拖拽时触发");
}

- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView
{
    NSLog(@"开始减速时触发");
}

// 当滚动减速停止的时候会触发的协议方法
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    if (scrollView.contentOffset.x == 11 * WIDTH) {
        scrollView.contentOffset = CGPointMake(WIDTH, 0);
    } else if (scrollView.contentOffset.x == 0) {
        scrollView.contentOffset = CGPointMake(WIDTH * 10, 0);
    }
    NSLog(@"滚动停止");
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)scrollViewWillBeginZooming:(UIScrollView *)scrollView withView:(UIView *)view
{
    NSLog(@"开始缩放的时候调用");
}

- (void)scrollViewDidZoom:(UIScrollView *)scrollView
{
    NSLog(@"正在缩放的时候调用");
}

- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale
{
    NSLog(@"完成放大缩小触发");
}

// 2.代码说明
// 实现缩放功能的4个步骤
// （1）为scrollview设置代理（self）
// （2）让控制器遵守scrollview的代理协议
// （3）调用代理方法，返回需要实现缩放功能的子控件
// （4）设置缩放的范围（最大和最小比例）
// 3.思路：
// a.需要告诉scrollview要缩放的时哪一个子控件，这里为scrollview内部的imageview控件
// b.谁来告诉scrollview缩放哪一个控件？代理
// 指定某个UISrollView的子视图可以被放大缩小
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    // 如何选定UISV的一个子视图
    // 对轮播图进行缩放后恢复竟然还能进行滚动...
    return scrollView.subviews[0];
}

UIPageControl
它一般不单独使用,需要和UIScrollView配合使用

#import "MainViewController.h"
#define WIDTH self.view.frame.size.width
#define HEIGHT self.view.frame.size.height
@interface MainViewController ()<UIScrollViewDelegate, UIPageViewControllerDelegate>

@property(nonatomic, retain)UIScrollView *scrollView;

@end

@implementation MainViewController

- (void)dealloc
{
    [_scrollView release];
    [super dealloc];
}

- (void)viewDidLoad {
    [super viewDidLoad];
//     Do any additional setup after loading the view.
    self.scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
    self.scrollView.contentSize = CGSizeMake(19 * WIDTH, HEIGHT);
    self.scrollView.pagingEnabled = YES;
    [self.view addSubview:self.scrollView];
    [self.scrollView release];
    self.scrollView.delegate = self;

    // scrollView的缩放
    // 最大缩放比例
    self.scrollView.maximumZoomScale = 1.4;
    // 最小缩放比例
    self.scrollView.minimumZoomScale = 0.5;
    // 这里的scrollView设置缩放比例还能手动滚动,为什么之前的程序不能?
    // 原始的缩放比例
    self.scrollView.zoomScale = 1;

    for (NSInteger i = 1; i < 20; i++) {
        UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[NSString stringWithFormat:@"image%ld.jpg", i]]];
        imageView.frame = CGRectMake(WIDTH * (i - 1), 0, WIDTH, HEIGHT);
        [self.scrollView addSubview:imageView];
        [imageView release];
    }

    UIPageControl *pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(0, 300, 375, 20)];
    pageControl.backgroundColor = [UIColor lightGrayColor];
    pageControl.alpha = 0.4;
    [self.view addSubview:pageControl];
    [pageControl release];
    pageControl.numberOfPages = 19;
    // 点的背景颜色
    pageControl.pageIndicatorTintColor = [UIColor whiteColor];
    // 被选中的原点颜色
    pageControl.currentPageIndicatorTintColor = [UIColor blackColor];
    pageControl.tag = 1000;

    // 它可以向button一样添加事件,只不过事件触发使用的是valuechanged
    [pageControl addTarget:self action:@selector(pageAction:) forControlEvents:UIControlEventValueChanged];
}

// 专门用来缩放的协议方法
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    // scrollView的子视图, 只对第一张进行缩放
    return [scrollView.subviews firstObject];
}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    // 滑动图片,让圆点跟着一起动
    UIPageControl *page = (UIPageControl *)[self.view viewWithTag:1000];
    page.currentPage = self.scrollView.contentOffset.x / WIDTH;
}

- (void)pageAction:(UIPageControl *)pageControl
{
    // 点的个数从第0张开始计算
    NSLog(@"%ld", pageControl.currentPage + 1);
    // 触发事件,进行图片的切换
//    self.scrollView.contentOffset = CGPointMake(pageControl.currentPage * WIDTH, 0);
    [self.scrollView setContentOffset:CGPointMake(pageControl.currentPage * WIDTH, 0) animated:YES];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end