iOS - 功能模块 - 幻灯片切换

来源：互联网发布：中国2015旅游数据分析编辑：程序博客网时间：2024/05/21 09:34

依据性能需求，实现iOS幻灯片切换功能。

1.图片少的情况下

这里写图片描述
Demo:https://github.com/shileseal/SLCarouselDemo

#import "ViewController.h"@interfaceViewController ()<UIScrollViewDelegate>@property (weak, nonatomic) IBOutletUIScrollView *scrollView;@property (weak, nonatomic) IBOutletUIPageControl *pageControl;@property (nonatomic, strong) NSTimer *timer;@end@implementation ViewController- (void)viewDidLoad {    [superviewDidLoad];    CGFloat imageW = self.scrollView.frame.size.width;    CGFloat imageH = self.scrollView.frame.size.height;    CGFloat imageY = 0;    NSInteger number = 5;    for (int i = 0; i < 5; i++) {        UIImageView *imageView = [[UIImageViewalloc]init];        NSString *imageUrl = [NSStringstringWithFormat:@"%d",i];        NSLog(@"%@",imageUrl);        imageView.image        = [UIImageimageNamed:imageUrl];        CGFloat imageX         = i * imageW;        imageView.frame        = CGRectMake(imageX, imageY, imageW, imageH);        self.scrollView.showsHorizontalScrollIndicator = NO;        [self.scrollViewaddSubview:imageView];    }    CGFloat contentW = number * imageW;    self.scrollView.contentSize = CGSizeMake(contentW, 0);    self.scrollView.pagingEnabled = YES;    self.scrollView.delegate = self;    [selfaddTimer];}- (void)nextImage {    int page = (int)self.pageControl.currentPage;    if (page == 4){        page = 0;    } else {        page ++;    }    CGFloat x = page * self.scrollView.frame.size.width;    self.scrollView.contentOffset = CGPointMake(x, 0);}- (void)scrollViewDidScroll:(UIScrollView *)scrollView {    NSLog(@"滚动中");    CGFloat scrollviewW = scrollView.frame.size.width;    CGFloat x = self.scrollView.contentOffset.x;    int page = (x + scrollviewW/2)/scrollviewW;    self.pageControl.currentPage = page;}- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {    [selfremoveTimer];}- (void)addTimer {    self.timer = [NSTimerscheduledTimerWithTimeInterval:1target:selfselector:@selector(nextImage) userInfo:nilrepeats:YES];}- (void)removeTimer {    [self.timerinvalidate];}@end

2.图片多的情况下，使用UICollectionView进行复用

这里写图片描述
Demo:https://github.com/shileseal/SLScrollViewReuseDemo

#import "ViewController.h"@interfaceViewController ()<UICollectionViewDataSource,UICollectionViewDelegate>@property (weak, nonatomic) IBOutletUICollectionView *collectionView;@end    staticNSString *identifier = @"cell";@implementation ViewController- (void)viewDidLoad {    [superviewDidLoad];    self.collectionView.delegate = self;    self.collectionView.dataSource = self;    [self.collectionViewregisterClass:[UICollectionViewCellclass] forCellWithReuseIdentifier:identifier];}#pragma mark - UICollectionViewDataSource- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {    return1;}- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {    return50;}- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:identifierforIndexPath:indexPath];    NSString *imageUrl = [NSStringstringWithFormat:@"%ld.png",(long)indexPath.row];    NSLog(@"%@",imageUrl);    UIImageView *imageView = [[UIImageViewalloc]initWithImage:[UIImageimageNamed:imageUrl]];    #warning 为什么这么写就无法显示呢？//    UIImageView *imageView = [[UIImageView alloc]init];//    imageView.image = [UIImage imageNamed:imageUrl];    [cell addSubview:imageView];    [cell bringSubviewToFront:imageView];    switch (indexPath.row%2) {        case1:            cell.backgroundColor = [UIColorwhiteColor];            break;        default:            cell.backgroundColor = [UIColorblueColor];            break;    }    NSLog(@"%@",cell);    return cell;}@end

3.iCarousel

https://github.com/nicklockwood/iCarousel

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