Question

首先我没有使用故事板这是完全以程序方式完成的，我无法让Cell出现在屏幕上，我相信这是因为函数collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath)没有被调用。什么可能导致这种情况？

import UIKit

class ChatLOGVC: UICollectionViewController {

    private let cellId = "Cell"

    override func viewDidLoad() {
        super.viewDidLoad()

        collectionView?.backgroundColor = UIColor.red

        collectionView?.register(FriendCell.self, forCellWithReuseIdentifier: cellId)
    }

    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 3
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
         print("cell for item at index path called")
         return collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath)
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize.init(width: view.frame.width, height: 80)
    }
}

class FriendCell: UICollectionViewCell {
    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = UIColor.blue
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError()
    }
}

Answer 1

您必须使用以下布局展示您的收藏VC：

let layout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 20, left: 10, bottom: 10, right: 10)
let to_chat_controller = ChatLOGVC(collectionViewLayout: layout)

Swift集合视图控制器单元格未显示，而单元格未被调用

1 个答案: