Loop scrolling of UIscrollView and UIPageControl and uipagecontrol

Loop scrolling of UIscrollView and UIPageControl and uipagecontrol

 

Because I have been searching for images on the Internet for a long time yesterday, many of them can only scroll to the right, and one image and one imageview have a terrible workload. The example below is no matter how many images you have, only a few values in my code are related. You only need to modify the maximum values of paging and cyclic I. Of course, you 'd better change the image name to an ordered one for convenience. It is convenient for you to add to a variable set.

 

 

 

 

 

 

 

 

 

If you have five or more pages, you can jump from the last graph to the first one.

In fact, there are only three images in total, and the images are added in a loop.

Code on

# Import <UIKit/UIKit. h> # define WIDTH self. view. bounds. size. width # define HEIGHT self. view. bounds. size. height @ interface ViewController: UIViewController <UIScrollViewDelegate> @ property (strong, nonatomic) UIScrollView * scrollview; @ property (strong, nonatomic) UIPageControl * pagecontrol; // Store Image @ property (strong, nonatomic) NSMutableArray * imageArray; // the current page number @ property (assign, nonatomic) int currentPage; // store the image @ property (strong, nonatomic) UIImageView * firstImage; @ property (strong, nonatomic) UIImageView * secondImage; @ property (strong, nonatomic) UIImageView * thirdImage; @ end

 

 

# Import "ViewController. h "@ interface ViewController () @ end @ implementation ViewController-(void) viewDidLoad {[super viewDidLoad]; self. scrollview = [[UIScrollView alloc] initWithFrame: CGRectMake (0, 20, WIDTH, HEIGHT)]; self. scrollview. contentSize = CGSizeMake (WIDTH * 3, 0); // whether the page is self. scrollview. pagingEnabled = YES; // Add proxy self. scrollview. delegate = self; // hide the scroll bar self. scrollview. showsHorizontalScrollIndicator = NO; [self. view addSubview: self. scrollview]; self. pagecontrol = [[UIPageControl alloc] initWithFrame: CGRectMake (WIDTH/5*3, HEIGHT/5*4, WIDTH/3, 40)]; // set the current page self. pagecontrol. currentPage = 0; // page self. pagecontrol. numberOfPages = 5; // specify the page color self. pagecontrol. currentPageIndicatorTintColor = [UIColor redColor]; self. pagecontrol. pageIndicatorTintColor = [UIColor blueColor]; [self. view addSubview: self. pagecontrol]; // initialize the set of stored images self. imageArray = [NSMutableArray array]; for (int I = 1; I <6; I ++) {UIImage * image = [UIImage imageNamed: [NSString stringWithFormat: @ "% d", I]; [self. imageArray addObject: image];} self. firstImage = [[UIImageView alloc] init]; self. secondImage = [[UIImageView alloc] init]; self. thirdImage = [[UIImageView alloc] init]; // the current page number self. currentPage = 0; [self reloadImage];}-(void) reloadImage {// first case, first page if (self. currentPage = 0) {self. firstImage. image = [self. imageArray lastObject]; self. secondImage. image = [self. imageArray objectAtIndex: self. currentPage]; self. thirdImage. image = [self. imageArray objectAtIndex: self. currentPage + 1];} // The last page of else if (self. currentPage = self. imageArray. count-1) {self. firstImage. image = [self. imageArray objectAtIndex: self. currentPage-1]; self. secondImage. image = [self. imageArray objectAtIndex: self. currentPage]; self. thirdImage. image = [self. imageArray objectAtIndex: 0];} // third case intermediate page else {self. firstImage. 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. firstImage. frame = CGRectMake (0, 0, WIDTH, HEIGHT); self. secondImage. frame = CGRectMake (WIDTH, 0, WIDTH, HEIGHT); self. thirdImage. frame = CGRectMake (WIDTH * 2, 0, WIDTH, HEIGHT); [self. scrollview addSubview: self. firstImage]; [self. scrollview addSubview: self. secondImage]; [self. scrollview addSubview: self. thirdImage]; self. scrollview. contentOffset = CGPointMake (WIDTH, 0);}-(void) scrollViewDidEndDecelerating :( UIScrollView *) scrollView {float x = self. scrollview. contentOffset. x; // left if (x <0 | x = 0) {if (self. currentPage = 0) {self. currentPage = (int) self. imageArray. count-1;} else {self. currentPage --;} // to the right 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