Question

我有一个自定义集合视图单元格：

class chatMessageCell: UICollectionViewCell {
let textView : UITextView = {
    let tv = UITextView()
    tv.text = "SAMPLE TEXT"
    tv.font = UIFont.systemFont(ofSize: 16)
    return tv
}()

override init(frame: CGRect) {
    super.init(frame: frame)
    backgroundColor = UIColor.red
    self.addSubview(textView)

    textView.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
    textView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
    textView.widthAnchor.constraint(equalToConstant: 200).isActive = true
    textView.heightAnchor.constraint(equalTo: self.heightAnchor).isActive = true
}

required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
  }
}

它也注册了：

override func viewDidLoad() {
    super.viewDidLoad()

    self.navigationItem.title = "Chat"

    collectionView?.delegate = self
    collectionView?.dataSource = self

    collectionView?.collectionViewLayout = UICollectionViewFlowLayout()
    collectionView?.backgroundColor = UIColor.white
    collectionView?.register(chatMessageCell.self, forCellWithReuseIdentifier: cellID)

}

并创建：

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

let message = messages[indexPath.item]
cell.textView.text = message.text

return cell
}

但是，屏幕上只显示了许多红色单元格，但它们不包含任何文本或文本视图。我做错了什么？

Answer 1

您应该将所有子视图添加到UICollectionView的contentView，而不是添加到UICollectionView实例本身。所以不要这样：

self.addSubview(textView)

试试这个：

self.contentView.addSubview(textView)

CollectionViewCell没有显示TextView

1 个答案: