iOS最笨的办法实现无限轮播图（网络加载）

iOS最笨的办法实现无限轮播图（网络加载）

简单的做了一下：

使用方法： 把 请求返回的 图片地址（字符串类型）放进数组中就行 
可以使用SDWebImage（我就是用的这个）等。。需要自己导入并引用，然后修改部分代码 
.h文件

//  ScrollViewTimerView.h
//  ScrollViewTimer
//
//  Created by 郑鹏 on 2016/12/9.
//  Copyright © 2016年 郑鹏. All rights reserved.
//

#import <UIKit/UIKit.h>

@protocol ScrollViewTimerViewDelegate <NSObject>

- (void)didSelectScrollViewWithSelectIndex:(NSInteger)selectIndex;

@end

@interface ScrollViewTimerView : UIView
@property (nonatomic, weak) id<ScrollViewTimerViewDelegate> littleSunDelegate;

- (instancetype)initWithFrame:(CGRect)frame animationDuration:(NSTimeInterval)animationDuration;
@property (nonatomic, strong) NSMutableArray * wheelImgArray;//轮播图 数组

//是否需要
@property (nonatomic, assign) BOOL isHidePageControl;

@end

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.m文件

//
//  ScrollViewTimerView.m
//  ScrollViewTimer
//
//  Created by 郑鹏 on 2016/12/9.
//  Copyright © 2016年 郑鹏. All rights reserved.
//

#import "ScrollViewTimerView.h"
#import "UIImageView+WebCache.h"

@interface ScrollViewTimerView ()<UIScrollViewDelegate>{

    NSTimer *_animationTimer;
    UIScrollView *_littleSunScrollView;
    UIPageControl *_pageControl;
}

@end

@implementation ScrollViewTimerView

- (instancetype)initWithFrame:(CGRect)frame animationDuration:(NSTimeInterval)animationDuration{
    self = [super initWithFrame:frame];

    _littleSunScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, frame.size.width, frame.size.height)];
    _littleSunScrollView.delegate = self;
    _littleSunScrollView.pagingEnabled = YES;
    _littleSunScrollView.showsHorizontalScrollIndicator = NO;
    _littleSunScrollView.showsVerticalScrollIndicator = NO;
    _littleSunScrollView.contentOffset = CGPointMake(self.frame.size.width, 0);
    [self addSubview:_littleSunScrollView];
    _animationTimer = [NSTimer scheduledTimerWithTimeInterval:animationDuration
                                                           target:self
                                                         selector:@selector(animationTimerDidFired:)
                                                         userInfo:nil
                                                          repeats:YES];

    [[NSRunLoop currentRunLoop] addTimer:_animationTimer forMode:UITrackingRunLoopMode];
    [self pauseTimer];

    return self;
}
- (void)animationTimerDidFired:(NSTimer *)timer{
    CGPoint newOffset = CGPointMake(_littleSunScrollView.contentOffset.x  + CGRectGetWidth(self.frame), _littleSunScrollView.contentOffset.y);
    [_littleSunScrollView setContentOffset:newOffset animated:YES];

    if (_littleSunScrollView.contentOffset.x >= (_wheelImgArray.count+1)*self.frame.size.width) {
        [self startTimerAfterTimeInterval:-2.0f];
        [_littleSunScrollView setContentOffset:CGPointMake(self.frame.size.width, 0) animated:NO];
    }
}

#pragma mark- UIScrollViewDelegate
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
    [self pauseTimer];
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
    [self startTimerAfterTimeInterval:2.0f];
}
-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
    if (_littleSunScrollView.contentOffset.x >= (_wheelImgArray.count+1)*self.frame.size.width) {
        [_littleSunScrollView setContentOffset:CGPointMake(self.frame.size.width, 0) animated:NO];
    }else if (_littleSunScrollView.contentOffset.x <= 0) {
        [_littleSunScrollView setContentOffset:CGPointMake(_wheelImgArray.count*self.frame.size.width, 0) animated:NO];
    }
    if (!_isHidePageControl) {
        _pageControl.currentPage = [self getCurrentPageBy:scrollView.contentOffset.x];
    }
}

//公开的属性设置
- (void)setWheelImgArray:(NSMutableArray *)wheelImgArray{
    if (_wheelImgArray != wheelImgArray) {
        _wheelImgArray = wheelImgArray;
        _littleSunScrollView.contentSize = CGSizeMake(self.frame.size.width * (wheelImgArray.count + 2), self.frame.size.height);
        for (NSInteger i = 0; i < wheelImgArray.count+2; i++) {
            if (i == 0) {
                [self creatImgViewWithFrame:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height) WithTag:20161212 + wheelImgArray.count - 1 WithImgName:wheelImgArray[wheelImgArray.count - 1]];
            }else if(i !=  wheelImgArray.count+1){
                [self creatImgViewWithFrame:CGRectMake(self.frame.size.width*i, 0, self.frame.size.width, self.frame.size.height) WithTag:20161212 + i-1 WithImgName:wheelImgArray[i-1]];
            }else if(i == wheelImgArray.count+1){
                [self creatImgViewWithFrame:CGRectMake(self.frame.size.width*i, 0, self.frame.size.width, self.frame.size.height) WithTag:20161212 WithImgName:wheelImgArray[0]];
            }
        }

        _pageControl = [[UIPageControl alloc] init];
        _pageControl.numberOfPages = _wheelImgArray.count;
        _pageControl.frame = CGRectMake(0, self.frame.size.height - 20, self.frame.size.width, 10);
        _pageControl.currentPage = 0;
        _pageControl.userInteractionEnabled = NO;
        [_pageControl setPageIndicatorTintColor:[UIColor colorWithRed:255.0 / 255.0 green:255.0 / 255.0 blue:255.0 / 255.0 alpha:0.5]];
        [_pageControl setCurrentPageIndicatorTintColor:[UIColor colorWithRed:255.0 / 255.0 green:255.0 / 255.0 blue:255.0 / 255.0 alpha:1]];
        [self addSubview:_pageControl];

        [self startTimerAfterTimeInterval:2.0f];
    }
}
- (void)creatImgViewWithFrame:(CGRect)frame WithTag:(NSInteger)tag WithImgName:(NSString *)imgName{

    UIImageView *imgView = [[UIImageView alloc] initWithFrame:frame];
    imgView.userInteractionEnabled = YES;
    imgView.contentMode = UIViewContentModeScaleAspectFill;
    imgView.tag = tag;
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(clickItem:)];
    [imgView addGestureRecognizer:tap];
    NSURL *imgUrl = [NSURL URLWithString:imgName];
    [imgView sd_setImageWithURL:imgUrl placeholderImage:[UIImage imageNamed:@"jiazai"]];
    [_littleSunScrollView addSubview:imgView];
}
-(void)setisHidePageControl:(BOOL)isHidePageControl{
    if (_isHidePageControl != isHidePageControl) {
        _isHidePageControl = isHidePageControl;
        if (_isHidePageControl) {
            [_pageControl removeFromSuperview];
        }
    }
}

//通过  计算 获取当前页
- (NSInteger)getCurrentPageBy:(CGFloat)scrollViewContentOfX{
    if (scrollViewContentOfX < self.frame.size.width) {
        return _wheelImgArray.count - 1;
    }else if (scrollViewContentOfX >= self.frame.size.width && scrollViewContentOfX < (_wheelImgArray.count+1)*self.frame.size.width) {
        return scrollViewContentOfX/self.frame.size.width - 1;
    }else{
        return 0;
    }
}

//_animationTimer暂停
-(void)pauseTimer{
    if (![_animationTimer isValid]) {
        return ;
    }
    [_animationTimer setFireDate:[NSDate distantFuture]];
}

//_animationTimer开始
-(void)startTimer{
    if (![_animationTimer isValid]) {
        return ;
    }
    [_animationTimer setFireDate:[NSDate date]];
}
//_animationTimer在多久后开始
- (void)startTimerAfterTimeInterval:(NSTimeInterval)interval{
    if (![_animationTimer isValid]) {
        return ;
    }
    [_animationTimer setFireDate:[NSDate dateWithTimeIntervalSinceNow:interval]];
}

#pragma mark-  实现代理
- (void)clickItem:(UITapGestureRecognizer *)tap{
    UIView *view = tap.view;
    if ([self.littleSunDelegate respondsToSelector:@selector(didSelectScrollViewWithSelectIndex:)]) {
        [self.littleSunDelegate didSelectScrollViewWithSelectIndex:view.tag - 20161212];
    }

}
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    // Drawing code
}
*/

@end