iOS开发-UIScrollView图片无限循环

关于UIScrollView图片浏览的例子有很多，之前也写过类似方面的文章，关于UIScrollView的图片循环在新闻类的App基本上是比较常见的一种情况就是图片浏览，然后根据不同的图片显示不同的内容显示不同的图片的介绍，因为属于比较常用的空间，先来看下需要实现的效果:



小圆点指示器是通过UIPageControl实现的，图片循环通过UIScrollView实现:

-(UIPageControl *)pageControl{
if (!_pageControl) {
_pageControl=[[UIPageControl alloc]initWithFrame:CGRectMake(0, 0, 150, 40)];
_pageControl.currentPage=0;
_pageControl.pageIndicatorTintColor=[UIColor whiteColor];
_pageControl.currentPageIndicatorTintColor=[UIColor greenColor];
}
return _pageControl;
}
-(UIScrollView *)scrollView{
if (!_scrollView) {
CGRect   screenRect=[[UIScreen mainScreen]bounds];
_scrollView=[[UIScrollView alloc]initWithFrame:CGRectMake(0, 64, CGRectGetWidth(screenRect), CGRectGetHeight(screenRect)-164)];
[_scrollView setBounces:NO];
[_scrollView setShowsHorizontalScrollIndicator:NO];
[_scrollView setPagingEnabled:YES];
_scrollView.delegate=self;
}
return _scrollView;
}

关于分页的页面配置以及页数Label的设置:

self.screenRect=[[UIScreen mainScreen]bounds];
CGFloat width=self.scrollView.bounds.size.width;
CGFloat height=self.scrollView.bounds.size.height;
self.imageArr=@[@"girl0.jpg",@"girl1.jpg",@"girl2.jpg"];
[self.scrollView setContentSize:CGSizeMake([self.imageArr count]*width, height)];

for (NSInteger i=0; i<[self.imageArr count]; i++) {
UIImageView  *imageView=[[UIImageView alloc]initWithFrame:CGRectMake(i*width, 0, width,height)];
imageView.image=[UIImage imageNamed:self.imageArr[i]];
imageView.contentMode=UIViewContentModeScaleToFill;
[self.scrollView  addSubview:imageView];
}
[self.view addSubview:self.scrollView];

self.pageControl.numberOfPages=[self.imageArr count];
self.pageControl.center=CGPointMake(self.scrollView.center.x, CGRectGetMaxY(self.scrollView.bounds)+50);
[self.view addSubview:self.pageControl];
self.pageLabel.text=[NSString stringWithFormat:@"%d/%lu",1,[self.imageArr count]];
[self.view addSubview:self.pageLabel];

实现UIScrollViewDelegate中scrollViewDidEndDecelerating的方法:

//博客园-FlyElephant 原文地址:http://www.cnblogs.com/xiaofeixiang/
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
if (self.currentPage==[self.imageArr count]-1) {
self.currentPage=0;
self.scrollView.contentOffset=CGPointMake(0, 0);
}else{
self.currentPage=scrollView.contentOffset.x/CGRectGetWidth(self.screenRect);
}
self.pageControl.currentPage=self.currentPage;
[self.pageLabel setText:[NSString stringWithFormat:@"%ld/%lu",self.currentPage+1,[self.imageArr count]]];
}

　简单的UIScrollView实现基本上ok了，当然关于UIScrollView根据不同场景去实现不同的功能代码量比这肯定更复杂~