Question

我正在使用仅允许单个选择的UICollectionView。我当前面临的问题是，即使按了其他选项卡/按钮以选择到另一个视图控制器，仍将保留突出显示的单元格。我想做的是，当我单击显示另一个视图控制器的其他选项卡时，突出显示的单元格将自动取消突出显示。

以下是我的代码：

override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {

    collectionView.allowsMultipleSelection = false


    collectionView.allowsSelection = true
    let cell = collectionView.cellForItem(at: indexPath)
    cell?.layer.borderWidth = 2.0
    cell?.layer.borderColor = UIColor.blue.cgColor
    if previouslySelected != nil{
        if let previousCell =  collectionView.cellForItem(at: previouslySelected!){
            previousCell.layer.borderWidth = 0
            previousCell.layer.borderColor = .none
        }
    }

}

override func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
    collectionView.allowsMultipleSelection = false
    let cell = collectionView.cellForItem(at: indexPath)
    cell?.layer.borderWidth = 0
    cell?.layer.borderColor = .none
    if previouslySelected != nil{
        if let previousCell =  collectionView.cellForItem(at: previouslySelected!){
            previousCell.layer.borderWidth = 0
            previousCell.layer.borderColor = .none
        }
    }


}

编辑：我注意到在按下next并选择其他单元格之后，选定的单元格会更改，但是上一个单元格仍会突出显示（尽管现在不再选择）。关于如何删除未选中的单元格的突出显示的任何想法？

Answer 1

只分享我如何解决它：

在class CollectionViewController: UICollectionViewController中声明

var currentlySelected: Int?
var previouslySelected: IndexPath?

下一步，在cellForItemAt函数中，

if currentlySelected != nil && currentlySelected == indexPath.row
        {
            uploadPostButton.isEnabled = true
            cell.layer.borderColor = UIColor.blue.cgColor
            cell.layer.borderWidth = 2.0
        }
        else
        {
            cell.layer.borderColor = .none
            cell.layer.borderWidth = 0
        }

也在didSelectItemAt

collectionView.allowsMultipleSelection = false
        if previouslySelected != nil{
            if let cell = collectionView.cellForItem(at: previouslySelected!){
                cell.layer.borderColor = .none
                cell.layer.borderWidth = 0
            }
        }
        currentlySelected = indexPath.row
        previouslySelected = indexPath

        // For reload the selected cell
        self.collectionView.reloadItems(at: [indexPath])//this is to "refresh" the selection

所以，这确实达到了我想要的目的，但是我敢肯定，我想学习一种更清洁/更好的方式！

如何在Swift 4.2的另一个View Controller中删除UICollectionView中的选定/突出显示的单元格

1 个答案: