我正在尝试从 youtube 教程创建一个类似 Facebook Messenger 的应用程序。我有一个主页，用户可以在其中单击 BarButton 打开聊天。主页工作正常，直到我单击 BarButton 打开聊天，它崩溃并显示以下错误消息“必须使用非零布局参数初始化 UICollectionView”。我是 iOS 开发的新手，所以无法真正理解问题出在哪里，因为我已经有了 init 方法。由于我有不同的观点，我是否在 AppDelegate 中遗漏了什么，这令人困惑 :( 。非常感谢您的帮助。谢谢!
class ChatViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.title = "Chats"
collectionView?.backgroundColor = UIColor.gray
// Do any additional setup after loading the view.
}
override func viewWillAppear(_ animated: Bool)
{
collectionView?.register(ChatCell.self, forCellWithReuseIdentifier: "cellID")
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 3
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cellID", for: indexPath)
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width, height: 100)
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
}
class ChatCell: UICollectionViewCell
{
override init(frame: CGRect)
{
super.init(frame: frame)
setupViews()
}
let profileImageView: UIImageView =
{
let imageView = UIImageView()
imageView.contentMode = .scaleAspectFill
imageView.translatesAutoresizingMaskIntoConstraints = false
return imageView
}()
func setupViews()
{
addSubview(profileImageView)
backgroundColor = UIColor.blue
addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[v0]|", options: NSLayoutFormatOptions(), metrics: nil, views: ["v0" : profileImageView]))
addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|[v0]|", options: NSLayoutFormatOptions(), metrics: nil, views: ["v0" : profileImageView]))
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
最佳答案
可能当你展示你的 ChatViewController 时，你有类似的东西:
让 chatVC = ChatViewController()
但根据 Apple 文档
类 UICollectionViewController
When you initialize the controller, using the init(collectionViewLayout:) method, you specify the layout the collection view should have.
所以你需要:
let chatVC = ChatViewController(collectionViewLayout: UICollectionViewFlowLayout())
关于ios - 错误 : UICollectionView must be initialized with a non-nil layout parameter，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47483529/