UIScrollView带图像，图像宽度不正确

Question

我有UIScrollView设置，可以从网络上加载图片。滚动视图中的UIImageView宽度为320像素，但不知何故，图像比此宽度更小或更大，并且在其他图像视图中可见时会发生干涉。

滚动视图中的每个图片如何精确地为320像素并且不会干扰其他图片

我使用以下代码：

CollectionViewController.m

#pragma mark - ScrollView Pics
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {

    UICollectionReusableView *reusableview = nil;

    if (kind == UICollectionElementKindSectionHeader) {

        UIView *headerView =[collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"HeaderView" forIndexPath:indexPath];

        reusableview = (UICollectionReusableView*)headerView;
        [self addSlideShow:reusableview at:indexPath];
    }

    return reusableview;
}

-(void)addSlideShow:(id)reusableView at:(NSIndexPath *)indexPath {

    int spacing = 4;
    int headerSpacing = (indexPath.section == 0) ? spacing : 8; // 8 = spacing + spacing
    int topSpacing = headerSpacing - spacing;


    float headHeight = self.customLayout.headerReferenceSize.height - headerSpacing;
    float pControlHeight = 20;

    self.myScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, topSpacing, self.view.frame.size.width, headHeight)];
    self.myScrollView.showsHorizontalScrollIndicator = NO;
    self.myScrollView.delegate = self;

    [reusableView addSubview:self.myScrollView];

    self.myPageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(0, headHeight - pControlHeight, self.view.frame.size.width, pControlHeight)];
    self.myPageControl.numberOfPages = 4; 
    self.myPageControl.enabled = TRUE;
    self.myPageControl.highlighted = TRUE;

    [reusableView addSubview:self.myPageControl];

    [self myScrollingAt:(int)indexPath.section];
    pageControlBeingUsed = NO;

}


-(void)myScrollingAt:(int)section {

    self.myScrollView.pagingEnabled = YES;
    [self.myScrollView setIndicatorStyle:UIScrollViewIndicatorStyleWhite];

    int numberOfViews = 4; 

    for (int i=0; i < numberOfViews; i++) {
        CGFloat xOrigin = i * self.myScrollView.frame.size.width;
        UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(xOrigin, 0, self.myScrollView.frame.size.width, self.myScrollView.frame.size.height)];

        imageView.contentMode = UIViewContentModeScaleAspectFill;
        imageView.userInteractionEnabled = YES;

        int itemOfScrollView = [self getItem:i atSection:section];

        if (self.sshare.coData.count > 0 && itemOfScrollView < self.sshare.coData.count) {

            [self setPhotos:imageView onItem:itemOfScrollView];
        }

        imageView.tag = 4000 + itemOfScrollView; // create tag to get the item to navigate to the detailView
        [self addTap:imageView];
        DLog(@"imageview %d: %@", i, imageView);

        [self.myScrollView addSubview:imageView];

    }    
    self.myScrollView.contentSize = CGSizeMake(numberOfViews * self.myScrollView.frame.size.width, self.myScrollView.frame.size.height);
}

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
    pageControlBeingUsed = NO;
}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
    pageControlBeingUsed = NO;
}

- (int)getItem:(int)item atSection:(int)section {
    return item + (section * 4); // return the positon where I have to look in my array
}

- (void)addTap:(id)view {
    UITapGestureRecognizer *myTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapToDetailView:)];
    paidTap.numberOfTapsRequired = 1;
    [view addGestureRecognizer:myTap];
}
-(void)setPhotos:(UIImageView *)imageView onItem:(int)item{
    NSString *imageUrl = [self.sshare myImage:item];
    [imageView setImageWithURL:[NSURL URLWithString:[self.sshare myImage:item]]];
}

调试器输出

[742:60b] -[ViewController myScrollingAt:] [Line 293] imageview 0: <UIImageView: 0x155502e0; frame = (0 0; 320 222.976); tag = 4000; gestureRecognizers = <NSArray: 0x15550680>; layer = <CALayer: 0x15550360>>
[742:60b] -[ViewController myScrollingAt:] [Line 293] imageview 1: <UIImageView: 0x1565fe30; frame = (320 0; 320 222.976); tag = 4001; gestureRecognizers = <NSArray: 0x1565f650>; layer = <CALayer: 0x15660260>>
[742:60b] -[ViewController myScrollingAt:] [Line 293] imageview 2: <UIImageView: 0x155508a0; frame = (640 0; 320 222.976); tag = 4002; gestureRecognizers = <NSArray: 0x155509a0>; layer = <CALayer: 0x155506b0>>
[742:60b] -[ViewController myScrollingAt:] [Line 293] imageview 3: <UIImageView: 0x155509d0; frame = (960 0; 320 222.976); tag = 4003; gestureRecognizers = <NSArray: 0x15550c00>; layer = <CALayer: 0x15550a50>>

Answer 1

由于您正在使用UIViewContentModeScaleAspectFill，因此您想剪切图片：

imageView.clipsToBounds = YES;

Aspect-fill缩放图像（保持其宽高比）以在绘制时完全填充可见区域。如果图像视图未设置为剪辑，则可能会在其边界之外绘制。