Question

我有UICollectionview，列数随机变化。每次列数更改时，我都会调用以下函数。

func setTheCollectionViewSize(){



    if self.activeLockerList.count > 0 {
        self.btnLockerDropdown.setTitle("Lockers Set \(self.activeLockerList[0].lockerId)", for: UIControlState.normal)
    }

    screenSize = UIScreen.main.bounds
    screenWidth = screenSize.width
    screenHeight = screenSize.height


    //if the collection view layout is not invalidated then the app will crash


    let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
    layout.minimumInteritemSpacing = 0
    layout.minimumLineSpacing = 0

    //setting the collectionview size so there will be no white lines in the drawn boxes
    var appropriateScreenWidth = Int(self.screenWidth)
    while appropriateScreenWidth % Int(self.numberOfLockersPerColumn) != 0 {
        appropriateScreenWidth = appropriateScreenWidth - 1
    }

    let itemWidth : CGFloat = CGFloat(appropriateScreenWidth) / self.numberOfLockersPerColumn
    collectionViewWidthLocal.constant = CGFloat(appropriateScreenWidth)
    layout.itemSize = CGSize(width: itemWidth, height: itemWidth)
    print(self.numberOfLockersPerColumn)
    print(screenWidth)

    layout.minimumInteritemSpacing = 0
    layout.minimumLineSpacing = 0
    layout.sectionInset = UIEdgeInsets(top: 10.0, left: 0, bottom: 10.0, right: 0)

    self.collectionView.collectionViewLayout.invalidateLayout()

    self.collectionView.setCollectionViewLayout(layout, animated: false)

}

当每行的细胞计数增加时，它可以正常工作。但是，当计数减少应用程序在self.collectionView.setCollectionViewLayout(layout, animated: false)

行崩溃时

正如您所看到的，使用self.collectionView.collectionViewLayout.invalidateLayout()使收藏视图无效也无济于事。我一直花费数小时仍然没有运气。提前谢谢。

Answer 1

您是否在setTheCollectionViewSize()之前或之后调用collectionView.reloadData()函数？

应按以下顺序进行。试着让我知道。

self.collectionView.reloadData()
self.setTheCollectionViewSize()

换句话说，以下应该是使collectionview无效时的顺序

self.collectionView.reloadData()
self.collectionView.collectionViewLayout.invalidateLayout()

希望它可以帮助你。

列数更改时，UICollectionView崩溃

1 个答案: