Objective-C实现无限循环轮播器

//// AppDelegate.m// 无限轮播器//// Created by zhangmi on 16/5/16.// Copyright © 2016年 Paramount Pictures. All rights reserved.//#import "ViewController.h"#import "SNInfiniteScrollView.h" @interface ViewController () @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib.   NSMutableArray * images = [NSMutableArray array]; for (int i = 0; i < 5; i++) {  NSString * imageName = [NSString stringWithFormat:@"ad_%02d", i]; //img01  UIImage * image = [UIImage imageNamed:imageName];  [images addObject:image]; } UIView * scrollView = [SNInfiniteScrollView scrollViewWithFrame:CGRectMake(0, 20, 414, 200) superView:self.view images:images scrollDirection:ScrollDirectionHorizontal pageIndicatorTintColor:[UIColor lightGrayColor] currentPageIndicatorTintColor:[UIColor orangeColor] imageViewcontentMode:UIViewContentModeScaleAspectFit];   [self.view addSubview:scrollView];} @end

//// AppDelegate.m// 无限轮播器//// Created by zhangmi on 16/5/16.// Copyright © 2016年 Paramount Pictures. All rights reserved.// #import "SNInfiniteScrollView.h" static int const ImageViewCount = 3;#define scrollViewWidth self.scrollView.frame.size.width#define scrollViewHeight self.scrollView.frame.size.height @interface SNInfiniteScrollView () <UIScrollViewDelegate> @property(weak, nonatomic) UIScrollView * scrollView;@property(weak, nonatomic) NSTimer * timer;/** pageIndex */@property(nonatomic, assign) NSInteger pageIndex; @end @implementation SNInfiniteScrollView - (void)setImages:(NSArray<UIImage *> *)images {   _images = images;   // 设置页码 self.pageIndex = 0;   // 设置内容 [self updateContent];   // 开始定时器 [self startTimer];} /** 代码创建的时候调用. */- (instancetype)initWithFrame:(CGRect)frame { if (self = [super initWithFrame:frame]) {  // 滚动视图  UIScrollView * scrollView = [[UIScrollView alloc] init];     self.scrollView = scrollView;  scrollView.delegate = self;  // scroller属性  scrollView.showsHorizontalScrollIndicator = NO;  scrollView.showsVerticalScrollIndicator = NO;  scrollView.pagingEnabled = YES;  scrollView.bounces = NO;  // 添加scrollView  [self addSubview:scrollView];     // 图片控件  for (int i = 0; i < ImageViewCount; i++) {   UIImageView * imageView = [[UIImageView alloc] init];   // 图片不变形处理.   imageView.contentMode = self.imageViewcontentMode;   [scrollView addSubview:imageView];  } } return self;}/** 布局 子控件, 只执行一次 */- (void)layoutSubviews { [super layoutSubviews];   self.scrollView.frame = self.bounds; if (self.scrollDirection == ScrollDirectionVertical) {  self.scrollView.contentSize = CGSizeMake(0, ImageViewCount * self.bounds.size.height); } else {  self.scrollView.contentSize = CGSizeMake(ImageViewCount * self.bounds.size.width, 0); }   for (int i = 0; i < ImageViewCount; i++) {  UIImageView * imageView = self.scrollView.subviews[i];     if (self.scrollDirection == ScrollDirectionVertical) {   imageView.frame = CGRectMake(0, i * self.scrollView.frame.size.height, self.scrollView.frame.size.width, self.scrollView.frame.size.height);  } else {   imageView.frame = CGRectMake(i * self.scrollView.frame.size.width, 0, self.scrollView.frame.size.width, self.scrollView.frame.size.height);  } } // 设置内容 [self updateContent];}#pragma mark - 内容更新- (void)updateContent { // 设置图片 for (int i = 0; i < self.scrollView.subviews.count; i++) {     NSInteger pageIndex = self.pageIndex;  // 遍历每一个imageView  UIImageView * imageView = self.scrollView.subviews[i];     if (i == 0) {   pageIndex--;  } else if (i == 2) {   pageIndex++;  }     if (pageIndex < 0) {   pageIndex = self.images.count - 1;  } else if (pageIndex >= self.images.count) {   pageIndex = 0;  }  // 图片角标 赋值给 imageView的tag  imageView.tag = pageIndex;  imageView.image = self.images[imageView.tag]; }   // 设置偏移量在中间 // 不能使用带动画 contentOffset if (self.scrollDirection == ScrollDirectionVertical) {  self.scrollView.contentOffset = CGPointMake(0, scrollViewHeight); } else {  self.scrollView.contentOffset = CGPointMake(scrollViewWidth, 0); }}#pragma mark - <UIScrollViewDelegate>- (void)scrollViewDidScroll:(UIScrollView *)scrollView { // 找出最中间的那个图片控件 NSInteger page = self.pageIndex; CGPoint point = CGPointZero; for (int i = 0; i < self.scrollView.subviews.count; i++) {  UIImageView * imageView = self.scrollView.subviews[i];  point = [scrollView convertPoint:imageView.frame.origin toView:self.superview];  //=****** other way ****************** stone ***  if (self.scrollDirection == ScrollDirectionVertical) {   if (ABS(point.y - self.frame.origin.y) < 1.0) {    page = imageView.tag;   }  } else {   if (ABS(point.x - self.frame.origin.x) < 1.0) {    page = imageView.tag;   }  } } self.pageIndex = page; self.pageControl.currentPage = page;   //拖动结束会调用 [self updateContent]; //#warning mark - 没有动画正常 , 有动画不动, 一直是原点 // [self updateContent]; // 没有动画正常 , 有动画不动, 一直是原点}/** 开始拖拽 */- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView { // 停止定时器 [self stopTimer];}/** 结束拖拽 */- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate { // 开启定时器 [self startTimer];}/** 减速完毕 */- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { // 更新内容 , 如果contentOffset 不带动画的话 不走这个方法 [self updateContent];}/** 结束滚动动画 */ // 这是保险的做法吧... 如果contentOffset 不带动画的话 不走这个方法- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView { // 更新内容 [self updateContent];} #pragma mark - 定时器处理- (void)startTimer {   NSTimer * timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(next:) userInfo:nil repeats:YES]; // [[NSRunLoop mainRunLoop] addTimer:timer forMode:NSRunLoopCommonModes]; [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes]; self.timer = timer;} - (void)stopTimer { [self.timer invalidate]; self.timer = nil;} - (void)next:(NSTimer *)timer { if (self.scrollDirection == ScrollDirectionVertical) {  [self.scrollView setContentOffset:CGPointMake(0, 2 * self.scrollView.frame.size.height) animated:YES]; } else {  [self.scrollView setContentOffset:CGPointMake(2 * self.scrollView.frame.size.width, 0) animated:YES]; }}//=****** 简单调用 ****************** stone ***+ (instancetype)scrollViewWithFrame:(CGRect)frame superView:(UIView *)superView images:(NSArray<UIImage *> *)images scrollDirection:(ScrollDirection)scrollDirection pageIndicatorTintColor:(UIColor *)pageIndicatorTintColor currentPageIndicatorTintColor:(UIColor *)currentPageIndicatorTintColor imageViewcontentMode:(UIViewContentMode)imageViewcontentMode {   //=****** 添加自定义scrollView ****************** stone *** SNInfiniteScrollView * scrollView = [[SNInfiniteScrollView alloc] init]; scrollView.frame = frame; scrollView.imageViewcontentMode = imageViewcontentMode; scrollView.scrollDirection = scrollDirection; //=****** 添加image ****************** stone *** scrollView.images = images; //=****** 添加pageControl ****************** stone *** UIPageControl * pageControl = [[UIPageControl alloc] init]; scrollView.pageControl = pageControl; pageControl.enabled = NO; pageControl.currentPageIndicatorTintColor = currentPageIndicatorTintColor; pageControl.pageIndicatorTintColor = pageIndicatorTintColor; pageControl.numberOfPages = scrollView.images.count; pageControl.bounds = CGRectMake(0, 0, scrollView.bounds.size.width, 44); pageControl.center = CGPointMake(scrollView.bounds.size.width * 0.5, scrollView.bounds.size.height * 0.9); [scrollView addSubview:pageControl]; [superView addSubview:scrollView]; //=************************ stone *** return scrollView;} @end