[UIScrollview 卡片式无限自动轮播]

卡片式无限自动轮播源码参考

scrollView的属性设置及解释

1.pagingEnable = yes  ; 开启分页模式,(ps为达到分页效果,可以设置contentSize为subView的整数倍width等)
 (iOS 自定义scrollView的pagingEnabled http://blog.csdn.net/liuxu0718/article/details/48344295)

2.clipsToBounds = NO; 关闭剪切图片,达到轮播的效果 (UIView里面都是默认开启的,只有UIScrollView默认关闭

3.ScrollsToTop  = YES;  该属性在垂直滚动时, 如果为YES则 点击状态栏会使UIScrollView滚动回初始位置
(谈一谈UIScrollView的scrollsToTop属性 http://www.jianshu.com/p/b4ac529950af)

4
CGRectInset CGRectoffset UIEdgeInsetsInsetRect 这三个函数的使用情况
(http://blog.csdn.net/ys410900345/article/details/42924827)

无限轮播的实现">第一部分:无限轮播的实现

下面是我画的图解,希望大家能看懂
这里写图片描述

RotateScrollview类的源码

仅用于解释上面的过程,复制过去可以自己实现效果

这里写图片描述
源码

#import "RotateScrollview.h"

@interface RotateScrollview ()<UIScrollViewDelegate>
/**
 *  原始页数
 */
@property(nonatomic, assign) NSInteger orginPageCount;

/**
 *  总页数
 */
@property(nonatomic, assign) NSInteger pageCount;

/**
 *  一页的尺寸
 */
@property(nonatomic, assign) CGSize pageSize;

/**
 左右间距,默认20
 */
@property(nonatomic, assign) CGFloat leftRightMargin;

/**
 上下间距,默认30
 */
@property(nonatomic, assign) CGFloat topBottomMargin;



@property (nonatomic, strong) UIScrollView *scrollView;

@end

@implementation RotateScrollview
@synthesize orginPageCount;
@synthesize pageCount;
@synthesize pageSize;
@synthesize leftRightMargin;
@synthesize topBottomMargin;


-(instancetype)initWithFrame:(CGRect)frame{

    if ([super initWithFrame:frame]) {
        [self initsilize];
    }return self;

}

- (void)initsilize{
    leftRightMargin = 10;
    topBottomMargin = 15;

    pageSize = CGSizeMake(self.bounds.size.width, self.bounds.size.height);
    orginPageCount = 5;
    pageCount = orginPageCount*3;
    self.scrollView = [[UIScrollView alloc] initWithFrame:self.bounds];
    self.scrollView.clipsToBounds = NO;
    self.scrollView.pagingEnabled = YES;
    self.scrollView.delegate = self;
    self.scrollView.showsVerticalScrollIndicator = YES;
    self.scrollView.showsHorizontalScrollIndicator = YES;

    [self addSubview:self.scrollView];

    for (int i = 0; i<15; i++) {
        UIImageView *imgV = [[UIImageView alloc] initWithFrame:self.bounds];
        //第一组
        if (i<=4) {
            UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"Yosemite%02d",i]];
            imgV.image = image;
        }
        //第二组
        if (i<=10&&i>4) {
            UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"Yosemite%02d",i-5]];
            imgV.image = image;
        }
        //第三组
        if (i<15&&i>9) {
            UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"Yosemite%02d",i-10]];
            imgV.image = image;
        }
        imgV.frame = CGRectMake(pageSize.width*i, 0, pageSize.width, pageSize.height);
        [self.scrollView addSubview:imgV];
    }

    self.scrollView.contentSize = CGSizeMake(pageSize.width*pageCount, 0);

    //设置scrollview的当前显示状态为 第二组
    [self.scrollView setContentOffset:CGPointMake(pageSize.width*orginPageCount*2, 0)];
}

#pragma  - mark UIScrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{

    //获取拖拽的下标
    NSInteger pageIndex;
    pageIndex = (int)round(_scrollView.contentOffset.x / pageSize.width) % orginPageCount;


    //向左滑动实现无限滚动
    if (scrollView.contentOffset.x / pageSize.width >= 2 * self.orginPageCount) {
        NSLog(@"%.f",scrollView.contentOffset.x / pageSize.width);
        //回到
        [scrollView setContentOffset:CGPointMake(pageSize.width * self.orginPageCount, 0) animated:NO];

    }
    //向右滑动实现无限滚动
    if (scrollView.contentOffset.x/ pageSize.width < self.orginPageCount -1) {

        [scrollView setContentOffset:CGPointMake(pageSize.width * (self.orginPageCount*2-1), 0) animated:NO];
    }

}