UICollectionview cellForItem返回nil

Question

错误：返回nil

for index in 0...totalHobbies - 1 {       
    let indexPath = IndexPath(item: index, section: 1) 
    print(indexPath) // Print [1, 0]
    let cell  = CollectionInterest.cellForItem(at: indexPath) as! CommanCollectionViewCell
    print(cell.btnInterestToggle.isSelected)
    if cell.btnInterestToggle.isSelected {

    }
}

  

致命错误：在解包可选值时意外发现nil

Answer 1

使用期权时你需要非常小心。

如果你强行打开可选值，那么你会在运行时崩溃。因此，在这种情况下，您可以使用if let或guard let。

for index in 0...totalHobbies - 1  {

        let indexPath = IndexPath(item: index, section: 1)

        if let cell  = CollectionInterest.cellForItem(at: indexPath) as? CommanCollectionViewCell {

            print(cell.btnInterestToggle.isSelected)
            if cell.btnInterestToggle.isSelected{

            }
        } else {
            print("not able to cast collection view cell class to `CommanCollectionViewCell` ")
        }
    }