Ios 使用未解析标识符'；UICollection&x27；在单独的UICollection类中

我有一节课，我将在上面的菜单视图上学习

代码如下：

import UIKit

class TopHomeMenuBar: UIView {

let collectionView: UICollectionView = {

    let layout = UICollectionViewFlowLayout()
    let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
    return cv
}()

override init(frame: CGRect) {
    super.init(frame: frame)

    addSubview(collectionView)

    backgroundColor = UIColor.systemGreen
}

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

然而，我不断得到错误：

使用未解析标识符“UICollection”

此代码行中突出显示UICollectionView时出错：

    let collectionView: UICollectionView = {

它确实有效

刚刚在XCODE中创建了一个简单的SinlgerView项目 我放置的I控制器（仅用于测试..通常视图有自己的文件..）

这样试试

private var collectionLayout = UICollectionViewFlowLayout()

lazy var collectionView: UICollectionView = {
    UICollectionView(frame: .zero, collectionViewLayout: collectionLayout)
}()

然后在

布局子视图中

根据需要设置流程布局

override func layoutSubviews() {
    super.layoutSubviews()

    collectionLayout.sectionInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
    collectionLayout.minimumLineSpacing = 0
    collectionLayout.itemSize = CGSize(width: (frame.width - 20) / 5, height: frame.height - 24)
    collectionLayout.scrollDirection = .horizontal
}

override func layoutSubviews() {
    super.layoutSubviews()

    collectionLayout.sectionInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
    collectionLayout.minimumLineSpacing = 0
    collectionLayout.itemSize = CGSize(width: (frame.width - 20) / 5, height: frame.height - 24)
    collectionLayout.scrollDirection = .horizontal
}