Ios Zoomscale UIScrollView不工作

我使用

UICollectionView

scroll direction holizontal，paginable=true创建PhotoViewer。我创建UICollectionViewCell包含UIScrollView以缩放UIImage
但是第一个创建UICollectionViewCell

zoomScale

工作，UICollectionCell重用

zoomScale

不工作

我的代码：

@interface ImageCell : UICollectionViewCell

@property (nonatomic, strong) UIImageView *imgView;
@property (nonatomic, strong) IBOutlet UIScrollView *scrollView;
@property (nonatomic, strong) NSString *stringURL;
@property (nonatomic, strong) UIImage *img;

- (void)resize;

@end

@interface ImageCell()<UIScrollViewDelegate>

@end

@implementation ImageCell

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

- (void)resize {
    SDWebImageManager *manager = [SDWebImageManager sharedManager];
    [manager downloadWithURL:[NSURL URLWithString:self.stringURL]
                     options:0
                    progress:^(NSInteger receivedSize, NSInteger expectedSize)
     {
         // progression tracking code

     }
     completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished) {
         if (image) {

             if(self.imgView == nil) {
                 self.imgView = [[UIImageView alloc] initWithFrame:self.frame];
                 [self.scrollView addSubview:self.imgView];
             }

             NSLog(@"%@", NSStringFromCGSize(image.size));
             self.img = image;

             self.imgView.frame = CGRectMake(0, 0, image.size.width, image.size.height);
             self.imgView.image = image;

             self.scrollView.contentSize = image.size;
             CGRect scrollViewFrame = self.scrollView.frame;
             CGFloat scaleWidth = scrollViewFrame.size.width / image.size.width;
             CGFloat scaleHeight = scrollViewFrame.size.height / image.size.height;
             CGFloat minScale = MIN(scaleWidth, scaleHeight);

             self.scrollView.minimumZoomScale = minScale;
             self.scrollView.maximumZoomScale = 1;
             [self.scrollView setZoomScale:minScale];

             [self centerScrollViewContents];
         }
     }];
}


- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return self.imgView;
}

@接口ImageCell:UICollectionViewCell
@属性（非原子，强）UIImageView*imgView；
@属性（非原子，强）IBUIScrollView*scrollView；
@属性（非原子，强）NSString*stringURL；
@属性（非原子，强）UIImage*img；
-（无效）调整大小；
@结束
@接口ImageCell（）
@结束
@实现ImageCell
-（id）initWithFrame:（CGRect）帧
{
self=[super initWithFrame:frame]；
如果（自我）{
//初始化代码
}
回归自我；
}
-（无效）调整大小{
SDWebImageManager*manager=[SDWebImageManager共享管理器]；
[manager downloadWithURL:[NSURL URLWithString:self.stringURL]
选项：0
进度：^（NSInteger接收大小，NSInteger预期大小）
{
//进程跟踪码
}
已完成：^（UIImage*图像，N错误*错误，SDImageCacheType cacheType，布尔已完成）{
如果（图像）{
if（self.imgView==nil）{
self.imgView=[[UIImageView alloc]initWithFrame:self.frame]；
[self.scrollView addSubview:self.imgView]；
}
NSLog（@“%@”，NSStringFromCGSize（image.size））；
self.img=图像；
self.imgView.frame=CGRectMake（0,0，image.size.width，image.size.height）；
self.imgView.image=图像；
self.scrollView.contentSize=image.size；
CGRect scrollViewFrame=self.scrollView.frame；
CGFloat scaleWidth=scrollViewFrame.size.width/image.size.width；
CGFloat SCALEHHEIGH=scrollViewFrame.size.height/image.size.height；
CGFloat minScale=MIN（标度宽度、标度高度）；
self.scrollView.minimumZoomScale=minScale；
self.scrollView.maximumZoomScale=1；
[self.scrollView setZoomScale:minScale]；
[self-centerScrollViewContents]；
}
}];
}
-（UIView*）视图用于缩放CrollView:（UICrollView*）滚动视图
{
返回self.imgView；
}

[self.scrollView setZoomScale:minScale]创建单元时工作，单元重用时不工作

因此，您还应该实现方法ScrollViewDiEndZooming:withView:atScale:

 The UIScrollView class can have a delegate that must adopt the UIScrollViewDelegate protocol. For zooming and panning to work, the delegate must implement both viewForZoomingInScrollView: and scrollViewDidEndZooming:withView:atScale: