CollectionView insde TableViewCell在iOS中无法正常工作

Question

I'm developing app which contains UICollectionView inside UITableViewCell. But what happens is that collection view's cell auto width is not working correctly when reloading data. Here's a screenshot.

Here's a code.

@IBOutlet weak var cv_inside: UICollectionView!
...
cv_inside.collectionViewLayout = AlignedCollectionViewFlowLayout(horizontalAlignment: .left, verticalAlignment: .top)

if let flowlayout = cv_inside.collectionViewLayout as? UICollectionViewFlowLayout {
    flowlayout.estimatedItemSize = CGSize(width: 1, height: 25)
    flowlayout.minimumLineSpacing = 10
}
cv_inside.isScrollEnabled = false
cv_inside.addObserver(self, forKeyPath: "contentSize", options: NSKeyValueObservingOptions.new, context: nil)
....
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
    cv_inside.layer.removeAllAnimations()
    heightOfCollectionViewConstant.constant = cv_inside.collectionViewLayout.collectionViewContentSize.height
    UIView.animate(withDuration: 0.5) {
        self.updateConstraints()
        self.layoutIfNeeded()
    }
}

It worked fine before iOS 12 and I researched that I have to add this code.

contentView.translatesAutoresizingMaskIntoConstraints = false
    let leftConstraint = contentView.leftAnchor.constraint(equalTo: leftAnchor)
    let rightConstraint = contentView.rightAnchor.constraint(equalTo: rightAnchor)
    let topConstraint = contentView.topAnchor.constraint(equalTo: topAnchor)
    let bottomConstraint = contentView.bottomAnchor.constraint(equalTo: bottomAnchor)
    NSLayoutConstraint.activate([leftConstraint, rightConstraint, topConstraint, bottomConstraint])

But even I added this code, it doesn't work. Can anyone please help me? Thanks.

Answer 1

Remove this line :

flowlayout.estimatedItemSize = CGSize(width: 1, height: 25)

you should also set cellSize in Interface Builder like this: