带有NSCollectionView的全宽NSCollectionViewFlowLayout

Question

我有一个NSCollectionViewFlowLayout包含以下内容:

- (NSSize) itemSize
{
    return CGSizeMake(self.collectionView.bounds.size.width, kItemHeight);
} // End of itemSize

- (CGFloat) minimumLineSpacing
{
    return 0;
} // End of minimumLineSpacing

- (CGFloat) minimumInteritemSpacing
{
    return 0;
} // End of minimumInteritemSpacing

我试图让布局响应(每当调整大小时设置宽度).我尝试添加以下内容:

[[NSNotificationCenter defaultCenter] addObserver: self
                                         selector: @selector(onWindowDidResize:)
                                             name: NSWindowDidResizeNotification
                                           object: nil];

- (void) onWindowDidResize: (NSNotification*) notification
{
    [connectionsListView.collectionViewLayout invalidateLayout];
} // End of windowDidResize:

如果我展开集合视图(调整大小),这可以正常工作.但是,如果我尝试折叠视图(调整较小),我会得到以下异常:

The behavior of the UICollectionViewFlowLayout is not defined because:
The item width must be less than the width of the UICollectionView minus the section insets left and right values, minus the content insets left and right values.
The relevant UICollectionViewFlowLayout instance is <TestListLayout: 0x106f70f90>, and it is attached to <NSCollectionView: 0x106f76480>.

关于如何解决这个问题的任何建议？

注意1:这是macOS而不是iOS(即使错误消息指出UICollectionViewFlowLayout).

注2:即使我收到警告/错误,布局宽度也有效,但我想找出潜在的问题.

Answer 1

我在问题中发布的源代码在 macOS 10.14 上运行良好，没有任何问题。我将以下内容添加到显示集合视图的窗口中。

// Only Mojave and after is resizable. Before that, a full sized collection view caused issues as listed
// at /sf/ask/3399712851/
if(@available(macOS 10.14, *))
{
    self.window.styleMask |= NSWindowStyleMaskResizable;
} // End of macOS 10.14+