IOS development-Carousel image module (continuous loop and rolling Version)

IOS development-Carousel image module (continuous loop and rolling Version)

// The ScrollView-based carousel module and the loop scroll // ViewController. m // Slider-Carousel-cyclic scrolling version /// Created by JamesXiang on 15/7/25. // Copyright (c) 2015 JamesXiang. all rights reserved. // # import ViewController. h @ interface ViewController ()
 
  
@ Property (nonatomic, strong) UIScrollView * scrollView; @ property (nonatomic, strong) UIPageControl * pageControl; @ property (nonatomic, strong) NSTimer * timer; @ property (nonatomic, assign) int pageIndex; @ property (nonatomic, assign) int pageCount; @ property (nonatomic, assign) double sliderWidth; @ property (nonatomic, assign) double sliderHeight; @ end @ implementation ViewController-(void) viewDidLoad {[super viewDidLoad]; [self loadSlider]; // The total carousel portal}-(void) loadSlider {// set related parameters [self setParams]; // load the carousel container [self loadSliderContainer]; // load the carousel content [self loadSliderItem]; // load the carousel page number controller [self loadSliderPageControl]; // start the carousel [self sliderBegin];}-(void) setParams {// set the page number to 0 self. pageIndex = 0; // The number of carousel content is 5 self. pageCount = 5; // set the carousel height to 160 self. sliderHeight = 160; // set the caster width to the screen width self. sliderWidth = self. view. frame. size. width;}-(void) loadSliderContainer {UIScrollView * scrollView = [[UIScrollView alloc] initWithFrame: CGRectMake (0, 20, self. sliderWidth, self. sliderHeight)]; scrollView. delegate = self; scrollView. pagingEnabled = YES; scrollView. showsHorizontalScrollIndicator = NO; // set contentSize scrollView. contentSize = CGSizeMake (self. sliderWidth * (self. pageCount + 2), self. sliderHeight); // sets the initial offset, which can be used to continuously scroll between the left and right sides of the basic scrollView. contentOffset = CGPointMake (self. sliderWidth, 0); scrollView. backgroundColor = [UIColor whiteColor]; _ scrollView = scrollView; [self. view addSubview: _ scrollView];}-(void) loadSliderItem {// principle of loop carousel: // the content to be carousel is slider0, slider1, slider2, slider3, slider4 // the actual content slider4-b in scrollView, slider0, slider1, slider2, slider3, slider4, slider0-b // The purpose of this construction is to reach the frontend side or the last side can be in the form of natural scrolling over to the next page // The Role Of The slider0-b: // when over slider0-b, modify the contentOffset of the scrollView to complete continuous scrolling // example: When scrolling to slider4, continue to scroll to the slider0-b, scroll finished, at this time // by modifying the contentOffset so that scrollView in the first position of the slider0 is displayed, and then continue to scroll to the Right to slider1, continuous scroll // The Role Of The slider4-b: // when the completion of a round of rolling back to slider0, by manually dragging to the right to move your fingers, if there is no slider4-b, it will lead to failure to pull // With the slider4-b, even if you pull it to the left, the content will still be displayed. // for specific mobile policies, see updateLocation Method for (int I = 0; I <self. pageCount + 2; I ++) {UIImageView * imgView = [[UIImageView alloc] initWithFrame: CGRectMake (self. sliderWidth * I, 0, self. sliderWidth, self. sliderHeight)]; // enables the imageView user interaction switch, allowing interaction with users [imgView setUserInteractionEnabled: YES]; [imgView addGestureRecognizer: [UITapGestureRecognizer alloc] initWithTarget: self action: @ selector (sliderClick)]; if (I = 0) {imgView. image = [UIImage imageNamed: [NSString stringWithFormat: @slider+d.jpg, self. pageCount-1];} else if (I = self. pageCount + 1) {imgView. image = [UIImage imageNamed: @slider0.jpg];} else {imgView. image = [UIImage imageNamed: [NSString stringWithFormat: @sliderd.jpg, I-1];} [self. scrollView addSubview: imgView] ;}}-(void) sliderClick {NSLog (@ click event... the user clicked the % d image. Please respond, self. pageIndex);}-(void) loadSliderPageControl {UIPageControl * pageControl = [[UIPageControl alloc] initWithFrame: CGRectMake (0, self. sliderHeight, self. sliderWidth, 20)]; pageControl. numberOfPages = self. pageCount; pageControl. currentPage = self. pageIndex; _ pageControl = pageControl; [self. view addSubview: _ pageControl];}-(void) sliderBegin {self. timer = [NSTimer scheduledTimerWithTimeInterval: 2.5 target: self selector: @ selector (changeSlider) userInfo: nil repeats: YES];}-(void) changeSlider {self. pageIndex ++; if (self. pageIndex = self. pageCount) {self. pageIndex = 0;} [UIView animateWithDuration: 0.8 animations: ^ {self. scrollView. contentOffset = CGPointMake (self. scrollView. contentOffset. x + self. sliderWidth, 0);} completion: ^ (BOOL finished) {self. pageControl. currentPage = self. pageIndex;}]; // update the page index and the Special Position Displacement [self updateIndexAndSpecialLocation];} // proxy method. When you start to pull it manually-(void) scrollViewWillBeginDragging :( UIScrollView *) scrollView {[self. timer invalidate];} // proxy method. After you manually pull and scroll,-(void) scrollViewDidEndDecelerating :( UIScrollView *) scrollView {[self updateIndexAndSpecialLocation]; self. pageControl. currentPage = self. pageIndex; [self sliderBegin];}-(void) updateIndexAndSpecialLocation {int index = self. scrollView. contentOffset. x/self. sliderWidth; if (index = 0) {// when a slider4-b page is currently displayed, self. pageIndex = self. pageCount-1; // modify the offset so that the following slider4 is displayed as self. scrollView. contentOffset = CGPointMake (self. sliderWidth * self. pageCount, 0);} else if (index = self. pageCount + 1) {// when the current slider0-b page is displayed // modify the offset so that the slider0 on the front is displayed as self. scrollView. contentOffset = CGPointMake (self. sliderWidth, 0); self. pageIndex = 0;} else {self. pageIndex = index-1 ;}@end