水平滚动集合视图单元格不根据内容宽度调整大小答案

【问题标题】：Horizontal scrolling collection view cells not resizing based on content width水平滚动集合视图单元格不根据内容宽度调整大小
【发布时间】：2021-04-17 05:28:39
【问题描述】：

我已经像这样初始化了集合视图：

 override init(frame: CGRect){
        let layout = UICollectionViewFlowLayout()
        layout.scrollDirection = .horizontal
        layout.itemSize = UICollectionViewFlowLayoutAutomaticSize
        layout.estimatedItemSize = CGSize(width: 100, height: 30)
        
        countryCollectionView = UICollectionView(frame: CGRect.zero, collectionViewLayout: layout)
        
        viewTitleLabel = UILabel()
        super.init(frame: frame)
        setupTableView()
        sortedDummyData = dummyData.sorted(by: <)
    }

我返回大小为CGSize.zero:

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
//        return CGSize(width: 70, height: 30)
        return CGSize.zero
    }

这是我的单元格的定义方式：

override init(frame: CGRect) {
        countryNameLabel = UILabel()
        countryUserCountLabel = UILabel()
        super.init(frame: frame)

        contentView.addSubview(countryNameLabel)
        countryNameLabel.translatesAutoresizingMaskIntoConstraints = false
        countryNameLabel.font = UIFont.boldSystemFont(ofSize: 13)
        countryNameLabel.textColor = .white
        
        contentView.addSubview(countryUserCountLabel)
        countryUserCountLabel.translatesAutoresizingMaskIntoConstraints = false
        countryUserCountLabel.font = UIFont.systemFont(ofSize: 13)
        countryUserCountLabel.textColor = .white
        
        NSLayoutConstraint.activate([
            countryNameLabel.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 5),
            countryNameLabel.heightAnchor.constraint(equalToConstant: 30),
            countryNameLabel.topAnchor.constraint(equalTo: self.topAnchor, constant: 5),
            countryNameLabel.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -5),
//            countryNameLabel.widthAnchor.constraint(greaterThanOrEqualToConstant: 0),
//            countryNameLabel.widthAnchor.constraint(equalToConstant: 20),

            countryUserCountLabel.leadingAnchor.constraint(equalTo: countryNameLabel.trailingAnchor, constant: 5),
            countryUserCountLabel.topAnchor.constraint(equalTo: self.topAnchor, constant: 5),
            countryUserCountLabel.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -5),
            countryUserCountLabel.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -5),
            countryUserCountLabel.heightAnchor.constraint(equalToConstant: 30),
            countryUserCountLabel.widthAnchor.constraint(equalToConstant: 40)
        ])
    }

这是我得到的输出：

【问题讨论】：

标签： ios swift uicollectionview uicollectionviewcell uicollectionviewlayout

【解决方案1】：

此更新对我有用：

返回非零单元格大小：

   func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: 70, height: 30)
//        return CGSize.zero
    }

更新单元格约束：

        NSLayoutConstraint.activate([
            countryNameLabel.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 5),
            countryNameLabel.heightAnchor.constraint(equalToConstant: 30),
            countryNameLabel.topAnchor.constraint(equalTo: self.topAnchor, constant: 5),
            countryNameLabel.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -5),
//            countryNameLabel.widthAnchor.constraint(greaterThanOrEqualToConstant: 0),
//            countryNameLabel.widthAnchor.constraint(equalToConstant: 20),

            countryUserCountLabel.leadingAnchor.constraint(equalTo: countryNameLabel.trailingAnchor, constant: 5),
            countryUserCountLabel.topAnchor.constraint(equalTo: self.topAnchor, constant: 5),
            countryUserCountLabel.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -5),
            countryUserCountLabel.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -5),
            countryUserCountLabel.heightAnchor.constraint(equalToConstant: 30),

// Removed the width constraint
//            countryUserCountLabel.widthAnchor.constraint(equalToConstant: 40)
        ])

【讨论】：