場景：

在開發工作中，有時我們需要實現一組圖片循環滾動的情況。當我們使用 UIScrollView 結合 UIImageView 來實現時，一般 UIImageView 會盡量考慮重用，下面例子是以（左中右）三個 UIImageView 的使用，其實也可以考慮使用 兩個 UIImageView 實現的情況。這樣避免 一組圖片多少個就對應多少個 UIImageView 所導致占用過多內存的情況。

效果如下：

#import <uikit uikit.h="">

@interface ViewController : UIViewController <uiscrollviewdelegate>
@property (strong, nonatomic) UIScrollView scrV;
@property (strong, nonatomic) UIPageControl pageC;
@property (strong, nonatomic) UIImageView imgVLeft;
@property (strong, nonatomic) UIImageView imgVCenter;
@property (strong, nonatomic) UIImageView imgVRight;
@property (strong, nonatomic) UILabel lblImageDesc;
@property (strong, nonatomic) NSMutableDictionary *mDicImageData;
@property (assign, nonatomic) NSUInteger currentImageIndex;
@property (assign, nonatomic) NSUInteger imageCount;
@end</uiscrollviewdelegate></uikit></pre>

ViewController.m 
#import "ViewController.h"

define kWidthOfScreen [[UIScreen mainScreen] bounds].size.width
define kHeightOfScreen [[UIScreen mainScreen] bounds].size.height
define kImageViewCount 3
@interface ViewController ()
/**

加載圖片數據
*/

(void)loadImageData;



/**

添加滾動視圖
*/

(void)addScrollView;



/**

添加三個圖片視圖到滾動視圖內
*/

(void)addImageViewsToScrollView;



/**

添加分頁控件
*/

(void)addPageControl;



/**

添加標簽；用于圖片描述
*/

(void)addLabel;



/**

根據當前圖片索引設置信息
*
@param currentImageIndex 當前圖片索引；即中間
*/

(void)setInfoByCurrentImageIndex:(NSUInteger)currentImageIndex;



/**

設置默認信息
*/

(void)setDefaultInfo;



/**

重新加載圖片
*/

(void)reloadImage;




(void)layoutUI;
@end

@implementation ViewController

(void)viewDidLoad {
  [super viewDidLoad];
[self layoutUI];
}

(void)didReceiveMemoryWarning {
  [super didReceiveMemoryWarning];
  // Dispose of any resources that can be recreated.
}

(void)loadImageData {
  NSString *path = [[NSBundle mainBundle] pathForResource:@"ImageInfo" ofType:@"plist"];
  _mDicImageData = [NSMutableDictionary dictionaryWithContentsOfFile:path];
  _imageCount = _mDicImageData.count;
}

(void)addScrollView {
  _scrV = [[UIScrollView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
  _scrV.contentSize = CGSizeMake(kWidthOfScreen * kImageViewCount, kHeightOfScreen);
  _scrV.contentOffset = CGPointMake(kWidthOfScreen, 0.0);
  _scrV.pagingEnabled = YES;
  _scrV.showsHorizontalScrollIndicator = NO;
  _scrV.delegate = self;
  [self.view addSubview:_scrV];
}

(void)addImageViewsToScrollView {
  //圖片視圖；左邊
  _imgVLeft = [[UIImageView alloc] initWithFrame:CGRectMake(0.0, 0.0, kWidthOfScreen, kHeightOfScreen)];
  _imgVLeft.contentMode = UIViewContentModeScaleAspectFit;
  [_scrV addSubview:_imgVLeft];
//圖片視圖；中間
  _imgVCenter = [[UIImageView alloc] initWithFrame:CGRectMake(kWidthOfScreen, 0.0, kWidthOfScreen, kHeightOfScreen)];
  _imgVCenter.contentMode = UIViewContentModeScaleAspectFit;
  [_scrV addSubview:_imgVCenter];
//圖片視圖；右邊
  _imgVRight = [[UIImageView alloc] initWithFrame:CGRectMake(kWidthOfScreen * 2.0, 0.0, kWidthOfScreen, kHeightOfScreen)];
  _imgVRight.contentMode = UIViewContentModeScaleAspectFit;
  [_scrV addSubview:_imgVRight];
}

(void)addPageControl {
  _pageC = [UIPageControl new];
  CGSize size= [_pageC sizeForNumberOfPages:_imageCount]; //根據頁數返回 UIPageControl 合適的大小
  _pageC.bounds = CGRectMake(0.0, 0.0, size.width, size.height);
  _pageC.center = CGPointMake(kWidthOfScreen / 2.0, kHeightOfScreen - 80.0);
  _pageC.numberOfPages = _imageCount;
  _pageC.pageIndicatorTintColor = [UIColor whiteColor];
  _pageC.currentPageIndicatorTintColor = [UIColor brownColor];
  _pageC.userInteractionEnabled = NO; //設置是否允許用戶交互；默認值為 YES，當為 YES 時，針對點擊控件區域左（當前頁索引減一，最小為0）右（當前頁索引加一，最大為總數減一），可以編寫 UIControlEventValueChanged 的事件處理方法
  [self.view addSubview:_pageC];
}

(void)addLabel {
  _lblImageDesc = [[UILabel alloc] initWithFrame:CGRectMake(0.0, 40.0, kWidthOfScreen, 40.0)];
  _lblImageDesc.textAlignment = NSTextAlignmentCenter;
  _lblImageDesc.textColor = [UIColor whiteColor];
  _lblImageDesc.font = [UIFont boldSystemFontOfSize:[UIFont labelFontSize]];
  _lblImageDesc.text = @"Fucking now.";
  [self.view addSubview:_lblImageDesc];
}

(void)setInfoByCurrentImageIndex:(NSUInteger)currentImageIndex {
  NSString *currentImageNamed = [NSString stringWithFormat:@"%lu.png", (unsigned long)currentImageIndex];
  _imgVCenter.image = [UIImage imageNamed:currentImageNamed];
  _imgVLeft.image = [UIImage imageNamed:[NSString stringWithFormat:@"%lu.png", (unsigned long)((_currentImageIndex - 1 + _imageCount) % _imageCount)]];
  _imgVRight.image = [UIImage imageNamed:[NSString stringWithFormat:@"%lu.png", (unsigned long)((_currentImageIndex + 1) % _imageCount)]];
_pageC.currentPage = currentImageIndex;
  _lblImageDesc.text = _mDicImageData[currentImageNamed];
}

(void)setDefaultInfo {
  _currentImageIndex = 0;
  [self setInfoByCurrentImageIndex:_currentImageIndex];
}

(void)reloadImage {
  CGPoint contentOffset = [_scrV contentOffset];
  if (contentOffset.x > kWidthOfScreen) { //向左滑動

  _currentImageIndex = (_currentImageIndex + 1) % _imageCount;

} else if (contentOffset.x < kWidthOfScreen) { //向右滑動

  _currentImageIndex = (_currentImageIndex - 1 + _imageCount) % _imageCount;

}
[self setInfoByCurrentImageIndex:_currentImageIndex];
}

(void)layoutUI {
  self.view.backgroundColor = [UIColor blackColor];
[self loadImageData];
  [self addScrollView];
  [self addImageViewsToScrollView];
  [self addPageControl];
  [self addLabel];
  [self setDefaultInfo];
}


pragma mark - UIScrollViewDelegate

(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
  [self reloadImage];
_scrV.contentOffset = CGPointMake(kWidthOfScreen, 0.0);
  _pageC.currentPage = _currentImageIndex;
NSString *currentImageNamed = [NSString stringWithFormat:@"%lu.png", (unsigned long)_currentImageIndex];
  _lblImageDesc.text = _mDicImageData[currentImageNamed];
}


@end</pre>

ImageInfo.plist 

 
來源：KenmuHuang的博客