iOS UIScrollView实用之图片轮播 —— HERO博客

来源：互联网发布：淘宝网电器城编辑：程序博客网时间：2024/05/21 08:37
上一篇简述了UIScrollView的属性及方法，本篇实际应用制作图片轮播效果。
具体属性及方法可以参考上一篇UIScrollView简介：UIScrollView简介
首先看一下效果图：
代码如下：
#import "ViewController.h"#define KWidth 320#define KHeight 180@interface ViewController ()<UIScrollViewDelegate>@property (nonatomic, strong) UIScrollView *scrollView;@property (nonatomic, weak) UIPageControl *pageControl;@property (nonatomic, strong) NSTimer *timer;@property (nonatomic, strong) NSArray *imageArray;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];        //初始化图片数组，展示4张图片（ABCD），首尾多添加2张（DABCDA）    self.imageArray =  @[@"04.jpg", @"01.jpg", @"02.jpg", @"03.jpg", @"04.jpg", @"01.jpg"];        //创建scrollView    [self createScrollView];        //创建pageControl    [self createPageControl];        //创建定时器    [self createNSTimer];}- (void)createScrollView{    //初始化    UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(28, 50, KWidth, KHeight)];    //循环添加图片    for (int i = 0; i < _imageArray.count; i++) {        UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(KWidth * i, 0, KWidth, KHeight)];        imageView.image = [UIImage imageNamed:_imageArray[i]];        [scrollView addSubview:imageView];    }    //设置可以滚动的区域    scrollView.contentSize = CGSizeMake(KWidth * _imageArray.count, 0);    //设置当前位置，图片应为第二张    scrollView.contentOffset = CGPointMake(KWidth, 0);    //设置代理    scrollView.delegate = self;    //整页翻动    scrollView.pagingEnabled = YES;    //隐藏水平方向滚动条    scrollView.showsHorizontalScrollIndicator = NO;        [self.view addSubview:scrollView];    self.scrollView = scrollView;}- (void)createPageControl{    //初始化    UIPageControl *pageControl = [[UIPageControl alloc]initWithFrame:CGRectMake(0, 0, 80, 30)];    //中心位置    pageControl.center = CGPointMake([UIScreen mainScreen].bounds.size.width * 0.5, CGRectGetMaxY(self.scrollView.frame) - 10);    //总页数    pageControl.numberOfPages = 4;    //当前页    pageControl.currentPage = 0;    //取消交互    pageControl.userInteractionEnabled = NO;        [self.view addSubview:pageControl];    self.pageControl = pageControl;}- (void)createNSTimer{    self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:@selector(nextPage) userInfo:nil repeats:YES];    [[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];}- (void)nextPage{    NSInteger currentPage = self.pageControl.currentPage;    currentPage++;    if (currentPage == 5) {        currentPage = 0;    }    [self.scrollView setContentOffset:CGPointMake((currentPage + 1) * KWidth, 0) animated:YES];}#pragma mark - UIScrollViewDelegate//滚动时调用- (void)scrollViewDidScroll:(UIScrollView *)scrollView{    int index = scrollView.contentOffset.x / KWidth + 0.5;        if (index > 0 && index < 5) {        _pageControl.currentPage = index - 1;            }else if (scrollView.contentOffset.x == KWidth * 5) {        _pageControl.currentPage = 0;        scrollView.contentOffset = CGPointMake(KWidth, 0);            }else if (scrollView.contentOffset.x == 0) {        _pageControl.currentPage = 3;        scrollView.contentOffset = CGPointMake(KWidth * 4, 0);    }}//开始拖拽视图调用- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{    [self.timer invalidate];    self.timer = nil;}//完成拖拽调用- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{    [self createNSTimer];}
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