iOS-UIScrollView和UIPageControl的综合实力，滚动图，轮播图

本代码主要实现图片之间的切换

代码

#import "ViewController.h"

@interface ViewController ()
@property(strong,nonatomic)UIScrollView *scrollView;
@property(strong,nonatomic)UIPageControl *pageControl;
//存储图片
@property(strong,nonatomic)UIImageView *firstIamges;
@property(strong,nonatomic)UIImageView *secondImage;
@property(strong,nonatomic)UIImageView *thirdImage;
//存储图片的集合
@property(strong,nonatomic)NSMutableArray *imageArray;
//当前页码
@property(assign,nonatomic)int currentPage;
@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];

self.scrollView=[[UIScrollView alloc]initWithFrame:CGRectMake(0, 20,WIDTH , HEIGHT)];
self.scrollView.contentSize=CGSizeMake(WIDTH*3, 0);
self.scrollView.pagingEnabled=YES;
self.scrollView.delegate=self;
self.scrollView.showsHorizontalScrollIndicator=NO;
[self.view addSubview:self.scrollView];

self.pageControl=[[UIPageControl alloc]initWithFrame:CGRectMake(WIDTH/2.7, 300, WIDTH/5, 20)];

//设置当前页
self.pageControl.currentPage=0;
//分页
self.pageControl.numberOfPages=5;
//指定页码的颜色
self.pageControl.currentPageIndicatorTintColor=[UIColor redColor];
self.pageControl.pageIndicatorTintColor=[UIColor blueColor];
[self.view addSubview:self.pageControl];

//初始化存储图片的集合
self.imageArray=[NSMutableArray array];
for (int i=1; i<6; i++) {
UIImage *image=[UIImage imageNamed:[NSString stringWithFormat:@"%d",i]];
[self.imageArray addObject:image];
}

self.firstIamges=[[UIImageView alloc]init];
self.secondImage=[[UIImageView alloc]init];
self.thirdImage=[[UIImageView alloc]init];

//当前页码
self.currentPage=0;
[self reloadImage];

}
-(void)reloadImage{
//第一种情况，第一页
if(self.currentPage==0){
self.firstIamges.image=[self.imageArray lastObject];
self.secondImage.image=[self.imageArray objectAtIndex:self.currentPage];
self.thirdImage.image=[self.imageArray objectAtIndex:self.currentPage+1];
}
//第二种情况 最后一页
else if(self.currentPage==self.imageArray.count-1){
self.firstIamges.image=[self.imageArray objectAtIndex:self.currentPage-1];
self.secondImage.image=[self.imageArray objectAtIndex:self.currentPage];
self.thirdImage.image=[self.imageArray objectAtIndex:0];
}
//中间页
else{

self.firstIamges.image=[self.imageArray objectAtIndex:self.currentPage-1];
self.secondImage.image=[self.imageArray objectAtIndex:self.currentPage];
self.thirdImage.image=[self.imageArray objectAtIndex:self.currentPage+1];
}

self.firstIamges.frame=CGRectMake(0, 0, WIDTH, 300);
self.secondImage.frame=CGRectMake(WIDTH, 0, WIDTH, 300);
self.thirdImage.frame=CGRectMake(WIDTH*2, 0, WIDTH, 300);

[self.scrollView addSubview:self.firstIamges];
[self.scrollView addSubview:self.secondImage];
[self.scrollView addSubview:self.thirdImage];

self.scrollView.contentOffset=CGPointMake(WIDTH, 0);
}

#pragma mark -Scrollview Delegate
//在滚动结束状态换图
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
float x=self.scrollView.contentOffset.x;

//向左
if (x<0||x==0) {
if (self.currentPage==0) {
self.currentPage=(int)self.imageArray.count-1;
}else{
self.currentPage--;
}

}
//向右

if(x>WIDTH*2||x==WIDTH*2){
if (self.currentPage==(int)self.imageArray.count-1) {
self.currentPage=0;
}else{
self.currentPage++;
}
}

self.pageControl.currentPage=self.currentPage;
[self reloadImage];

}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end

#import <UIKit/UIKit.h>
#define WIDTH self.view.frame.size.width
#define HEIGHT self.view.frame.size.height
@interface ViewController : UIViewController<UIScrollViewDelegate>

@end

效果图