ios - 更改 UICollectionView 中选定单元格的文本大小

Question

我正在尝试更改 Collection View 单元格标签的文本大小并稍微起作用。当我明智地选择项目索引(单元格 0、单元格 1、单元格 2....)时，它对我有用但是当我尝试在随机索引上选择项目(例如:单元格 0 到单元格 3)时，我的应用程序崩溃了

我正在尝试这段代码:

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath)  {
    let idxPath = IndexPath(item: indexPath.item, section: 0)
    let cell = collectionView.cellForItem(at: idxPath)
    let myCell = collectionView.cellForItem(at: idxPath) as! MenuCell
    cell?.isSelected = true
    myCell.isSelected = true
    myCell.title.font = UIFont.systemFont(ofSize: 16)
    collectionView.scrollToItem(at: idxPath, at: UICollectionViewScrollPosition.centeredHorizontally, animated: true)
}
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
    let idxPath = IndexPath(item: indexPath.item, section: 0)
    let myCell = collectionView.cellForItem(at: idxPath) as! MenuCell
    myCell.isSelected = false
    myCell.title.font = UIFont.systemFont(ofSize: 13)
}

它在串联电池选择中起作用

enter image description here

但是当我随机选择单元格时

enter image description here

谢谢，抱歉我的英语不好

Answer 1

因为您重新创建了 IndexPath，然后对单元格强制展开。 如果您只需要为第一部分更改字体，请尝试像这样更改代码:

func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
    if indexPath.section == 0 {
      let myCell = collectionView.cellForItem(at: indexPath) as? MenuCell
       myCell?.isSelected = false
       myCell?.title.font = UIFont.systemFont(ofSize: 13)
    }
}