如何解决NSCollectionViewItem重叠问题？

Question

我使用NSCollectionView来显示一个水平列表。但所有单元格在第一个单元格位置重叠，如下所示。

我没有足够的名气来发布图片。cell1、cell2、cell3，它们都在第一个单元格位置重叠。所以它看起来像一个细胞，但实际上它有3个细胞。

我的主要代码：

ViewController.h

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.flowLayout.scrollDirection = NSCollectionViewScrollDirectionHorizontal;
    self.collectionView.dataSource = self;
    self.collectionView.delegate = self;
    self.collectionView.selectable = YES;
    self.collectionView.allowsMultipleSelection = YES;
    [self.collectionView registerNib:[[NSNib alloc] initWithNibNamed:@"ScreenShotCellView" bundle:nil] forItemWithIdentifier:NSStringFromClass([ScreenShotCellView class])];
}

#pragma mark - NSCollectionViewDataSource
- (NSInteger)numberOfSectionsInCollectionView:(NSCollectionView *)collectionView {
    [self.collectionView.collectionViewLayout invalidateLayout];
    return 1;
}

- (NSInteger)collectionView:(NSCollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return self.screenshotItems.count;
}

- (NSCollectionViewItem *)collectionView:(NSCollectionView *)collectionView itemForRepresentedObjectAtIndexPath:(NSIndexPath *)indexPath {
    NSCollectionViewItem *itemCell = [self.collectionView makeItemWithIdentifier:NSStringFromClass([ScreenShotCellView class]) forIndexPath:indexPath];
    if ([itemCell isKindOfClass:[ScreenShotCellView class]]) {
        ScreenShotCellView *cellView = (ScreenShotCellView *)itemCell;
        ScreenshotItem *itemData = [self.screenshotItems objectAtIndex:indexPath.item];
        cellView.item = itemData;
    }
    return itemCell;
}

#pragma mark - NSCollectionViewDelegateFlowLayout
- (NSSize)collectionView:(NSCollectionView *)collectionView layout:(NSCollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    return CGSizeMake(100, self.collectionView.frame.size.height - 20);
}

- (CGFloat)collectionView:(NSCollectionView *)collectionView layout:(NSCollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
    return 10;
}

- (CGFloat)collectionView:(NSCollectionView *)collectionView layout:(NSCollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
    return 10;
}

我该怎么做才能修复它呢？

Answer 1

我已经找到原因了。问题出在我的自定义单元格中。

@interface ScreenShotCellView ()

@property (weak) IBOutlet NSView *containerView;

@end

@implementation ScreenShotCellView

- (void)loadView {
    self.view = self.containerView;
}

@end

在loadView方法中。self.view = self.containerView; make始终显示在第一个单元格中。

经过这样的改变，它就变得正常了。

- (void)loadView {
    self.view = [[NSView alloc] init];
    [self.view addSubview:self.containerView];
}