Question

我正在使用自定义collectionCell构建UICollectionView。但是我得到了错误：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'UICollectionView must be initialized with a non-nil layout parameter'

但是从代码中我可以看到，我非常明确地创建了布局，并在初始化集合视图时将其作为参数传递。

import UIKit

private let reuseIdentifier = "Cell"

class ProfileViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {

override func viewDidLoad() {
    super.viewDidLoad()
    sentMngr.retrieveSent()
    let flow = UICollectionViewFlowLayout()
    flow.sectionInset = UIEdgeInsets(top: 20, left: 10, bottom: 10, right: 10)
    flow.itemSize = CGSize(width: 90, height: 90)
    flow.scrollDirection = UICollectionViewScrollDirection.Vertical

    self.collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: flow)
    self.collectionView!.dataSource = self
    self.collectionView!.delegate = self
    self.collectionView!.backgroundColor = UIColor.blackColor()
    // Uncomment the following line to preserve selection between presentations
    // self.clearsSelectionOnViewWillAppear = false

    // Register cell classes
    self.collectionView!.registerClass(CollectionCell.self, forCellWithReuseIdentifier: reuseIdentifier)
    self.view.addSubview(self.collectionView!)

    // Do any additional setup after loading the view.
}

自定义单元格代码：

import UIKit

class CollectionCell: UICollectionViewCell {
var imageView: UIImageView!
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func drawRect(rect: CGRect) {
    // Drawing code
}
*/
override init(frame: CGRect) {
    super.init(frame: frame)

    imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: frame.size.width, height: frame.size.height*2/3))
    imageView.contentMode = UIViewContentMode.ScaleAspectFit
    self.addSubview(imageView)

}

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

}

Answer 1

尝试将代码替换为：

import UIKit

private let reuseIdentifier = "Cell"

class ProfileViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {

override func viewDidLoad() {
    super.viewDidLoad()

    sentMngr.retrieveSent()

    self.collectionView!.backgroundColor = UIColor.blackColor()
    // Uncomment the following line to preserve selection between presentations
    // self.clearsSelectionOnViewWillAppear = false

    // Register cell classes
self.collectionView!.registerClass(CollectionCell.self, forCellWithReuseIdentifier: reuseIdentifier)
   self.view.addSubview(self.collectionView!)

  // Do any additional setup after loading the view.
}

Answer 2

Swift 3.0

我遇到同样的问题，应用程序一启动就崩溃了。初始化时工作正常如下

var alarmCollectionView = UICollectionView(frame: CGRect.zero, collectionViewLayout: UICollectionViewFlowLayout.init())

我正在使用autoLayout，所以在框架中使用了CGRect.zero

UICollectionView崩溃，因为布局参数是“nil”..但它不是 - Swift

2 个答案: