特性:无限轮播的what's new,含有icon和title
方案一:使用UIScrollView,同时创建n个contentView
方案二:使用UICollectionView,创建若干干contentView,然后复用
这里只介绍相对优雅的方案二
@class LoopPageView;
@protocol LoopPageViewDelegate <NSObject>
- (void)loopPageView:(LoopPageView *)pageView didSelectItemAtIndex:(NSInteger)index;
@end
@interface LoopPageView : UIView
@property(nonatomic, strong) UIPageControl *pageControl;
@property(nonatomic, weak) id<LoopPageViewDelegate>delegate;
- (void)setImages:(NSArray *)images titles:(NSArray *)titles;
@end
@interface LoopPageView ()<UICollectionViewDataSource,UICollectionViewDelegate>
{
NSArray *_images;
NSArray *_titles;
NSInteger _totalItemCount;
UICollectionViewFlowLayout *_flowLayout;
UICollectionView *_collectionView;
NSTimer *_timer;
}
@end
static NSString *kCollectionViewCellIdentify = @"kCollectionViewCell";
@implementation LoopPageView
- (id)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame]) {
_flowLayout = [[UICollectionViewFlowLayout alloc] init];
_flowLayout.minimumLineSpacing = 0;
_flowLayout.sectionInset = UIEdgeInsetsZero;
_flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
_collectionView = [[UICollectionView alloc] initWithFrame:self.bounds collectionViewLayout:_flowLayout];
_collectionView.backgroundColor = [UIColor clearColor];
_collectionView.delegate = self;
_collectionView.dataSource = self;
_collectionView.pagingEnabled = YES;
_collectionView.showsHorizontalScrollIndicator = NO;
_collectionView.autoresizingMask = UIViewAutoresizingFlexibleWidth;
[_collectionView registerClass:[ImageTextCollectionViewCell class] forCellWithReuseIdentifier:kCollectionViewCellIdentify];
[self addSubview:_collectionView];
_pageControl = [[UIPageControl alloc] init];
_pageControl.pageIndicatorTintColor = HexColor(@"#D9D9D9");
_pageControl.currentPageIndicatorTintColor = HexColor(@"#42C642");
[self addSubview:_pageControl];
}
return self;
}
- (void)dealloc
{
[self invalidateTimer];
}
- (void)setImages:(NSArray *)images titles:(NSArray *)titles
{
if (images.count != titles.count) {
NSAssert(0, @"imagesCount != titlesCount");
}
_images = images;
_titles = titles;
_totalItemCount = _images.count;
if (images.count != 1) {
[self setupTimer];
_pageControl.numberOfPages = images.count;
}
[_collectionView reloadData];
}
- (void)setupTimer
{
_timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(autoScroll) userInfo:nil repeats:YES];
[[NSRunLoop mainRunLoop] addTimer:_timer forMode:NSRunLoopCommonModes];
}
- (void)autoScroll
{
NSInteger targetIndex = [self currentIndex] + 1;
targetIndex = (targetIndex >= _totalItemCount) ? targetIndex %= _totalItemCount : targetIndex;
[_collectionView scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:targetIndex inSection:0] atScrollPosition:UICollectionViewScrollPositionNone animated:YES];
}
- (NSInteger)currentIndex
{
if (_collectionView.frame.size.width == 0) return 0;
return (_collectionView.contentOffset.x + _flowLayout.itemSize.width * 0.5) / _flowLayout.itemSize.width;
}
- (void)invalidateTimer
{
[_timer invalidate];
_timer = nil;
}
- (void)layoutSubviews
{
[super layoutSubviews];
_flowLayout.itemSize = self.frame.size;
_collectionView.frame = self.bounds;
if (_collectionView.contentOffset.x == 0 && _totalItemCount) {
NSInteger tarIndex = _totalItemCount * 0.5;
[_collectionView scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:tarIndex inSection:0] atScrollPosition:UICollectionViewScrollPositionNone animated:NO];
}
if (CGRectEqualToRect(_pageControl.frame, CGRectZero)) {
_pageControl.frame = CGRectMake((self.width - 100)/2, self.height - 30, 100, 20);
}
}
#pragma mark - UICollectionViewDataSource
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return _totalItemCount;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
UIImage *image = _images[indexPath.item % _images.count];
NSString *title = _titles[indexPath.item % _images.count];
ImageTextCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kCollectionViewCellIdentify forIndexPath:indexPath];
[cell updateImage:image title:title];
return cell;
}
#pragma mark - UICollectionViewDelegate
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
NSInteger index = indexPath.item % _images.count;
if ([_delegate respondsToSelector:@selector(loopPageView:didSelectItemAtIndex:)]) {
[_delegate loopPageView:self didSelectItemAtIndex:index];
}
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
NSInteger index = [self currentIndex];
_pageControl.currentPage = index % _images.count;
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
[self invalidateTimer];
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
[self setupTimer];
}
@end
特性:修改UIPageControl小圆点的颜色
_pageControl.pageIndicatorTintColor = [UIColor lightGrayColor];
_pageControl.currentPageIndicatorTintColor = [UIColor grayColor];