swift - selectItem 时的集合视图布局错误（Swift 5）

Question

从 viewDidLoad 布局中选择单元格后更改

在选择单元格之前

选择单元格后

let indexPath = IndexPath(row: SelectedFolderIndex, section: 0)       
collectionView.selectItem(at: indexPath, animated: false, scrollPosition: .centeredVertically)

布局

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    return CGSize(width: collectionView.frame.width/2.2, height: 55)
}

ViewDidLoad

let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 7, left: 12, bottom: 12, right: 12)
layout.minimumInteritemSpacing = 5
layout.minimumLineSpacing = 11
collectionView!.collectionViewLayout = layout
collectionView.delegate = self
collectionView.dataSource = self
collectionView.allowsMultipleSelection = false

Answer 1

您需要从单元格宽度中剪切插图和间距：

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    let width = (collectionView.frame.width/2.2) - 2*12 - 11
    return CGSize(width: width, height: 55)
}

Answer 2

当您设置时，scrollPosition: .centeredVertically您正在设置滚动后的项目将位于中心并垂直对齐，就像您在您的案例中看到的那样。尝试查看https://developer.apple.com/documentation/uikit/uicollectionview/1618057-selectitem以更改您想要的行为