iOS-快速生成一个轮播视图

改几个小地方就可以直接使用了。

#define kImageCount 2

@interface ScrollViewController ()<UIScrollViewDelegate>

@property (weak, nonatomic) IBOutlet UIScrollView *scrollView;
@property (weak, nonatomic) IBOutlet UIPageControl *pageControl;
@property (nonatomic, weak) NSTimer *timer;

@end

@implementation ScrollViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    [self pLScroLLview];
}

- (void)pLScroLLview
{
    // 1.添加图片(frame-改)
    CGFloat imageW = self.view.bounds.size.width;
    CGFloat imageH = 130;
    CGFloat imageY = 0;
    for (int index = 0; index <= kImageCount; index++) {
        CGFloat imageX = index * imageW;
        UIImageView *imageView = [[UIImageView alloc] init];
        imageView.frame = CGRectMake(imageX, imageY, imageW, imageH);
        imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"img_%02d", index+1]];//(改)
        [self.scrollView addSubview:imageView];
    }
    
    // 2.设置内容区域
    self.scrollView.contentSize = CGSizeMake(kImageCount * self.scrollView.bounds.size.width, 0);
    
    // 3.设置分页控件起始页数
    self.pageControl.currentPage = 0;
    
    // 4.添加时钟
    [self startTimer];
}

- (void)startTimer
{
    self.timer = [NSTimer timerWithTimeInterval:2.0 target:self selector:@selector(updateTimer) userInfo:nil repeats:YES];
    [[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSDefaultRunLoopMode];
}

- (void)updateTimer
{
    self.pageControl.currentPage = (self.pageControl.currentPage + 1) % kImageCount;
    [self pageChanged:self.pageControl];
}

#pragma mark - 分页控件监听方法
- (void)pageChanged:(UIPageControl *)page
{
    CGFloat x = page.currentPage * self.scrollView.bounds.size.width;
    [self.scrollView setContentOffset:CGPointMake(x, 0) animated:YES];
}

#pragma mark - 滚动视图代理方法
/** 滚动停止 */
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    // 根据contentOffset计算页数
    int page = scrollView.contentOffset.x / scrollView.bounds.size.width;
    self.pageControl.currentPage = page;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    if (self.timer) return;
    self.pageControl.currentPage = (scrollView.contentOffset.x + scrollView.frame.size.width * 0.5) / scrollView.frame.size.width;
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    [self.timer invalidate];
    self.timer = nil;
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
    [self startTimer];
}



@end