Ios UICollectionViewCell layoutSubview已调用但不工作

我正在对UICollectionView单元格进行子类化，以便在多个CollectionView中具有统一的舍入。它适用于第一个collectionview，但不适用于第二个（单独的VC）。我错过了什么？谢谢

下面是我要尝试的子类：

class RoundedCollectionViewCell: UICollectionViewCell {

    override func layoutSubviews() {

    self.layer.cornerRadius = 20.0
    self.layer.masksToBounds = true

    self.contentView.layer.cornerRadius = 15.0
    self.contentView.layer.borderWidth = 5.0
    let borderColor: UIColor = .clear
    self.contentView.layer.borderColor = borderColor.cgColor
    self.contentView.layer.masksToBounds = true
    self.layer.shadowColor = UIColor.white.cgColor
    self.layer.shadowOffset = CGSize(width: 0, height: 0.0)
    self.layer.shadowRadius = 2.0
    self.layer.shadowOpacity = 0.6
    self.layer.cornerRadius = 2.0
    self.layer.masksToBounds = false
    self.layer.shadowPath = UIBezierPath(roundedRect: self.bounds, cornerRadius: self.contentView.layer.cornerRadius).cgPath

    print("RoundedCollectionViewCell called") //This prints correctly

}
}

以下是未将单元格舍入的VC：

import UIKit

class PeopleViewController: UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {

var persons : [Person] = []

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return persons.count
}

@IBOutlet weak var peopleCollectionView: UICollectionView!

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
      let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "PeopleCell", for: indexPath) as! PeopleCollectionViewCell

    cell.label.text = persons[indexPath.row].name

    return cell
}

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

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {

    let noOfCellsInRow = 2
    let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
    let totalSpace = flowLayout.sectionInset.left
        + flowLayout.sectionInset.right
        + (flowLayout.minimumInteritemSpacing * CGFloat(noOfCellsInRow - 1))
    let size = Int((collectionView.bounds.width - totalSpace) / CGFloat(noOfCellsInRow))
    return CGSize(width: size, height: size)

}

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

     if let cell = sender as? UICollectionViewCell,
        let indexPath = self.peopleCollectionView.indexPath(for: cell) {
        let vc = segue.destination as! PersonViewController
        vc.personToHighlight = persons[indexPath.row] //Pass specific person
     }
}

override func viewDidLoad() {
    super.viewDidLoad()
}

}

最后，细胞本身：

import UIKit

class PeopleCollectionViewCell: RoundedCollectionViewCell {

@IBOutlet weak var label: UILabel!

}

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使用awakefromnib方法代替layoutSubviews（）尝试它；没有解决问题。