自定义控件（2） - 性能优化循环图片滚动
功能：
1，显示多张循环滚动的图片；可以加载网络图片（传入url数组）；可以加载本地图片；可以开启和关闭自动循环滚动；三个imageView循环使用不会创建大量
imageView而引起性能问题
注意：
1，需要导入SDWebImage
2，如果使用url显示图片的话，本地图片数组会失效
源码地址：
https://github.com/SSBun/iOS-Custom-Control/tree/master/图片轮滚视图（2）
// // BZImageScrollView.h // 668PetHotel // // Created by 蔡士林 on 15/11/4. // Copyright © 2015年 wby. All rights reserved. // // BZImageScrollView.h #import <UIKit/UIKit.h> @class BZImageScrollView; @protocol BZImageScrollViewDelegate <NSObject> /// 点击的图片内容 - (void)imageScrollViewDidClickImage:(BZImageScrollView *)imageScrollView andImageData:(UIImage *)image; /// 点击的图片下标 - (void)imageScrollViewDidClickImage:(BZImageScrollView *)imageScrollView andClickIndex:(NSInteger)index; @end @interface BZImageScrollView : UIView /// 要滚动显示的图片url数组 @property (strong, nonatomic) NSArray<NSString *> *imageDatas; /// 要滚动的图片数组（如果有url数组则失效） @property (strong, nonatomic) NSArray<UIImage *>* photos; @property (assign, nonatomic) id <BZImageScrollViewDelegate> delegate; /// 自动滚动 @property (assign, nonatomic, getter=isAutoScroll) BOOL autoScroll; @end
// // BZImageScrollView.m // 668PetHotel // // Created by 蔡士林 on 15/11/4. // Copyright © 2015年 wby. All rights reserved. // // BZImageScrollView.m #import "BZImageScrollView.h" @interface BZImageScrollView ()<UIScrollViewDelegate> @property (strong, nonatomic) UIScrollView *mainScrollView; @property (strong, nonatomic) UIImageView *leftImageView; @property (strong, nonatomic) UIImageView *centerImageView; @property (strong, nonatomic) UIImageView *rightImageView; @property (assign, nonatomic) NSInteger imageCount; @property (assign, nonatomic) NSInteger currentImageIndex; @property (strong, nonatomic) UIPageControl *pageControl; @property (assign, nonatomic) NSInteger pageControlCurrentPage; @property (strong, nonatomic) NSTimer *timer; @end @implementation BZImageScrollView - (instancetype)initWithFrame:(CGRect)frame { self = [super initWithFrame:frame]; if (self) { [self setUpUI]; _currentImageIndex = 0; } return self; } - (void)setUpUI { _mainScrollView = [[UIScrollView alloc]init]; _mainScrollView.delegate = self; _mainScrollView.showsHorizontalScrollIndicator = NO; _mainScrollView.showsVerticalScrollIndicator = NO; _mainScrollView.pagingEnabled = YES; [self addSubview:_mainScrollView]; _leftImageView = [self imageView]; _centerImageView = [self imageView]; _rightImageView = [self imageView]; self.pageControl = [[UIPageControl alloc]init]; [self addSubview:self.pageControl]; self.pageControl.pageIndicatorTintColor = UIColorFromRGB(KPlaceHolderG); self.pageControl.currentPageIndicatorTintColor = UIColorFromRGB(kNormalOrange); } - (UIImageView *)imageView { UIImageView *imageView = [[UIImageView alloc]init]; imageView.userInteractionEnabled = YES; [_mainScrollView addSubview:imageView]; UITapGestureRecognizer *tapGes = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(imageViewDidClick:)]; [imageView addGestureRecognizer:tapGes]; return imageView; } - (void)layoutSubviews { [super layoutSubviews]; _mainScrollView.frame = self.bounds; _leftImageView.frame = CGRectMake(0, 0, self.width, self.height); _centerImageView.frame = CGRectMake(self.width, 0, self.width, self.height); _rightImageView.frame = CGRectMake(self.width * 2, 0, self.width, self.height); _mainScrollView.contentSize = CGSizeMake(self.width * 3, self.height); [_mainScrollView setContentOffset:CGPointMake(self.width, 0)]; self.pageControl.centerX = self.self.width/2; self.pageControl.y = self.height - 20; } - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { [self mainScrollViewDidScroll:scrollView]; } - (void)mainScrollViewDidScroll:(UIScrollView *)scrollView { if ((self.imageDatas.count != 0 && self.imageDatas != nil) || (self.photos.count != 0)) { NSInteger allPage = self.imageDatas.count != 0 ? self.imageDatas.count : self.photos.count; if (scrollView.contentOffset.x > self.width) { _currentImageIndex = (_currentImageIndex + 1) % self.imageCount; self.pageControlCurrentPage ++; if (self.pageControlCurrentPage >= allPage) { self.pageControlCurrentPage = 0; } } else if (scrollView.contentOffset.x < self.width) { _currentImageIndex = (_currentImageIndex + self.imageCount -1) % self.imageCount; self.pageControlCurrentPage --; if (self.pageControlCurrentPage < 0) { self.pageControlCurrentPage = allPage - 1; } } self.pageControl.currentPage = self.pageControlCurrentPage; if (self.imageDatas.count != 0) { [_leftImageView sd_setImageWithURL:[NSURL URLWithString:self.imageDatas[(_currentImageIndex + _imageCount - 1) % _imageCount]] placeholderImage:PLACEHOLDER_BIG_IMAGE]; [_rightImageView sd_setImageWithURL:[NSURL URLWithString:self.imageDatas[(_currentImageIndex + 1) % self.imageCount]] placeholderImage:PLACEHOLDER_BIG_IMAGE]; [_centerImageView sd_setImageWithURL:[NSURL URLWithString:self.imageDatas[_currentImageIndex % self.imageCount]] placeholderImage:PLACEHOLDER_BIG_IMAGE]; } else { [_leftImageView setImage:self.photos[(_currentImageIndex + _imageCount - 1) % self.imageCount]]; [_rightImageView setImage:self.photos[(_currentImageIndex + 1) % self.imageCount]]; [_centerImageView setImage:self.photos[_currentImageIndex % self.imageCount]]; } [scrollView setContentOffset:CGPointMake(self.width, 0)]; } } - (void)setImageDatas:(NSArray<NSString *> *)imageDatas { _imageDatas = imageDatas; if (imageDatas.count == 0) { self.hidden = YES; } else { self.hidden = NO; [_centerImageView sd_setImageWithURL:[NSURL URLWithString:imageDatas[0]] placeholderImage:PLACEHOLDER_BIG_IMAGE]; self.imageCount = imageDatas.count; self.pageControl.numberOfPages = imageDatas.count; self.pageControl.currentPage = 0; self.currentImageIndex = 0; self.pageControlCurrentPage = 0; } if (self.isAutoScroll) { [self beginScroll]; } } - (void)setPhotos:(NSArray<UIImage *> *)photos { _photos = photos; if (photos.count == 0) { self.hidden = YES; } else { self.hidden = NO; [_centerImageView setImage:photos[0]]; self.imageCount = photos.count; self.pageControl.numberOfPages = photos.count; self.pageControl.currentPage = 0; self.currentImageIndex = 0; self.pageControlCurrentPage = 0; } if (self.isAutoScroll) { [self beginScroll]; } } - (NSInteger)imageCount { if (self.imageDatas.count == 0) { return self.photos.count; } return self.imageDatas.count; } - (void)imageViewDidClick:(UITapGestureRecognizer *)tap { if ([self.delegate respondsToSelector:@selector(imageScrollViewDidClickImage:andImageData:)]) { [self.delegate imageScrollViewDidClickImage:self andImageData:((UIImageView *)tap.view).image]; } if ([self.delegate respondsToSelector:@selector(imageScrollViewDidClickImage:andClickIndex:)]) { [self.delegate imageScrollViewDidClickImage:self andClickIndex:self.pageControl.currentPage]; } } - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event { [super touchesBegan:touches withEvent:event]; if (self.timer) { [self.timer setFireDate:[NSDate distantFuture]]; } } - (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event { [super touchesEnded:touches withEvent:event]; if (self.timer) { [self.timer setFireDate:[NSDate distantPast]]; } } - (void)beginScroll { NSTimer *timer = [ NSTimer timerWithTimeInterval:3 target:self selector:@selector(didAutoScroll) userInfo:nil repeats:YES]; [[NSRunLoop mainRunLoop] addTimer:timer forMode:NSRunLoopCommonModes]; [timer setFireDate:[NSDate distantPast]]; self.timer = timer; } - (void)didAutoScroll { [UIView animateWithDuration:0.5 animations:^{ [self.mainScrollView setContentOffset:CGPointMake(self.width * 2, 0)]; } completion:^(BOOL finshed) { [self mainScrollViewDidScroll:self.mainScrollView]; }]; } @end
