UICollectionViewFlowLayout vs子类化UICollectionViewLayout [英] UICollectionViewFlowLayout vs subclassing UICollectionViewLayout

问题描述

我知道如果您正在执行任何像网格或基于行的分解布局，则记录的建议是使用UICollectionView Flow 布局。但是，我不确定这是否适用于我的情况。

I know the documented advice is to use UICollectionViewFlowLayout if you are doing anything "like a grid or a line-based breaking layout". However, I am not sure this is true for my case.

我想要一个网格，但不想要一个换行符布局。物品应无限制地水平和垂直布置，无需堆叠。基本上，如果内容超出框架，则可以水平或垂直滚动​​的巨型棋盘。

I want a grid but do not want a line-breaking layout. Items should be laid out infinitely both horizontally and vertically without ever stacking. Essentially, a giant chessboard that scrolls horizontally or vertically if content goes beyond the frame.

要继承UICollectionView Flow 布局，我必须：

To subclass UICollectionViewFlowLayout I would have to:

1. 覆盖 prepareLayout 以阻止布局包装项目。这似乎很多工作。


2. 覆盖 collectionViewContentSize 。

1. Override prepareLayout to stop the layout from wrapping items. This seems like a lot of work.
2. Override collectionViewContentSize.

Apple说他们在制作UICollectionView Flow 布局方面做了很多艰苦的工作，所以如果可以，我应该利用它。但是如果我必须覆盖 prepareLayout 来关闭换行符，我怀疑我丢掉了他们大部分的工作。在剩下的工作中，我可能不会使用大部分工作（例如， minimumLineSpacingForSectionAtIndex ）。

Apple says they have done "lots of hard work" in crafting UICollectionViewFlowLayout, so I should leverage it if I can. But if I have to override prepareLayout to turn off line-breaking, I suspect that I am throwing away a large part of their work. Of their work that is left, I probably will not use most of it anyway (for example, minimumLineSpacingForSectionAtIndex).

因为我想要的布局非常简单，我怀疑我应该继承UICollectionViewLayout，因为：

Because the layout I want is so simple, I suspect that I should subclass UICollectionViewLayout instead, because:

1. 我会更简单，更清洁在一个布局类中实现所有内容而不是在子类和委托之间传播。


2. 我认为它不会比继承UICollectionView Flow 更难布局，因为我必须在两种情况下都覆盖 prepareLayout ，我怀疑这是所有艰苦工作的地方。


3. 我'能够以自定义方式调整其他UICollectionViewLayoutAttributes比尝试在UICollectionView Flow 布局子类之上添加另一个kludge更好。

1. I will have a simpler and cleaner implementation with everything in one layout class instead of spread between a subclass and a delegate.
2. I don't think it will be that much harder than subclassing UICollectionViewFlowLayout because I have to override prepareLayout in both cases, and I suspect that is where all the hard work will be.
3. I'll be in a better position to tweak other UICollectionViewLayoutAttributes in custom ways than trying to add another kludge on top of a UICollectionViewFlowLayout subclass.

我的结论是否正确？

推荐答案

UICollectionVie wFlowLayout 无论如何都不能支持两个方向，它只能沿着一个轴滚动，水平或垂直。所以你必须继承 UICollectionViewLayout 而不是 UICollectionViewFlowLayout 。

UICollectionViewFlowLayout can't support two directions anyway, it scrolls along one axis only, either horizontally or vertically. So you have to subclass UICollectionViewLayout not UICollectionViewFlowLayout.

然后你必须覆盖 prepareForLayout ， layoutsAttributesForElementsInRect 方法正如您所说..

Then you have to override prepareForLayout, layoutsAttributesForElementsInRect methods as you said correctly..

这篇关于UICollectionViewFlowLayout vs子类化UICollectionViewLayout的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！