最近闲来无事,封装了一个无限图片轮播器,基于collectionView完成,抽取了两个API,一个是创建轮播器,一个是点击图片的跳转,使用的话,直接把JZLCycleView这个文件夹拖进项目,调用API就完成了,非常简单
更新:
2016.12.21 解决控制器被销毁时,timer不被释放造成的内存泄漏
1.无限轮播思路:
建了图片数量*3个数的cell,然后去一直显示中间的cell,到最后一组的第一个,无动画滚动到中间一组的第一个,到第一组的最后一个,无动画滚动到中间一组的最后一个
2.调用的方法,使用直接调用API
_cycleView = [JZLCycleView cycleCollectionViewWithFrame:CGRectMake(0, 0, JZLScreenWidth, JZLCycleViewHeight) imageArray:arrTemp PlaceholderImage:[UIImage imageNamed:@"placeholderImage"]];
//小圆点颜色设置,自己根据需求更改,默认黑色和白色
_cycleView.pageControl.pageIndicatorTintColor = [UIColor orangeColor];
_cycleView.pageControl.currentPageIndicatorTintColor = [UIColor whiteColor];
//如果要跳转记得遵守协议,设置代理
_cycleView.delegate = self;
_cycleView.clickItemBlock = ^(NSInteger index){
NSLog(@"%ld",(long)index);
};
[self.view addSubview:_cycleView];
2.1跳转这一块封装了两个,一个block,一个代理,个人认为代理更清晰一些
//block跳转
_cycleView.clickItemBlock = ^(NSInteger index){
NSLog(@"%ld",(long)index);
};
//代理跳转
- (void)selectItemAtIndex:(NSInteger)index {
NSLog(@"%ld",index);
}
3.实现
1.初始化轮播器,这里抽取了两个,一个是加载本地图片,一个是加载网路url,一般开发中第二个用的比较多
/**
初始化实例
@param frame 图片轮播器frame
@param imageArray 本地图片数组(可传图片url和本地图片,自动判断)
@param placeholderImage 占位图
@return 图片轮播器
*/
+ (instancetype)cycleCollectionViewWithFrame: (CGRect)frame imageArray: (NSArray *)imageArray PlaceholderImage: (UIImage *)placeholderImage;
2.主要的就是去完成collectionView
//设置collectionView
- (void)setupCollcetionView {
//collcetionView
UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];
UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:self.bounds collectionViewLayout:flowLayout];
flowLayout.itemSize = CGSizeMake(self.bounds.size.width, self.bounds.size.height);
flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
flowLayout.minimumLineSpacing = 0;
collectionView.pagingEnabled = YES;
collectionView.bounces = NO;
collectionView.showsHorizontalScrollIndicator = NO;
collectionView.delegate = self;
collectionView.dataSource = self;
[collectionView registerClass:[JZLCollectionViewCell class] forCellWithReuseIdentifier: reuseID];
[self addSubview:collectionView];
self.collectionView = collectionView;
//pageControl
self.pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(self.bounds.size.width / 2 - 50, self.bounds.size.height - 20, 100, 20)];
//默认一张,加载图片后自动更新
self.pageControl.numberOfPages = 1;
self.pageControl.currentPage = 0;
[self addSubview:self.pageControl];
}
3.添加定时器以及手动滚动和自动滚动的切换
//设置页码
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
self.pageControl.currentPage = (NSInteger)(scrollView.contentOffset.x / scrollView.bounds.size.width)%self.imageArray.count;
}
//添加定时器
- (void)addTimer {
self.timer = [NSTimer scheduledTimerWithTimeInterval:automaticTime target:self selector:@selector(automaticScrollCollectionCell) userInfo:nil repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
}
//删除定时器
- (void)deleteTimer {
[self.timer invalidate];
self.timer = nil;
}
//自动滚动
- (void)automaticScrollCollectionCell {
self.index++;
if (self.imageArray.count == 0) {
return;
}else {
NSIndexPath *indexPath = [NSIndexPath indexPathForItem:self.index inSection:0];
[self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:0 animated:YES];
if (indexPath.row == self.imageArray.count * 2) {
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
NSIndexPath *indexPath = [NSIndexPath indexPathForItem:self.imageArray.count inSection:0];
[self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:0 animated:NO];
});
}
self.pageControl.currentPage = self.index % self.imageArray.count ;
}
}
//手动滚动时删除定时器
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
[self deleteTimer];
if (self.imageArray.count == 0) {
return;
}else {
if (self.index == self.imageArray.count - 1) {
[self.collectionView scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:self.imageArray.count * 2 - 1 inSection:0] atScrollPosition:0 animated:NO];
}
if (self.index == self.imageArray.count * 2) {
[self.collectionView scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:self.imageArray.count inSection:0] atScrollPosition:0 animated:NO];
}
}
}
//停止滚动时打开定时器
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
[self addTimer];
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
self.index = (NSInteger)(scrollView.contentOffset.x / scrollView.bounds.size.width);
}
git地址:https://github.com/allenjzl/JZLCycleView.git
swift版本:https://github.com/allenjzl/JZLCycleView_Swift.git
下载图片用了sdwebImage,demo的话报错记得icocoaPods里面install一下,如果大家发现有崩溃或者问题,请留言,谢谢
