NSCollectionView 中的选择突出显示

NSCollectionView 中的选择突出显示

swift
// 定义数据源
class CollectionViewDataSource: NSObject, NSCollectionViewDataSource {
    // 返回项目数量
    func collectionView(_ collectionView: NSCollectionView, numberOfItemsInSection section: Int) -> Int {
        return 10
    }
    
    // 返回项目视图
    func collectionView(_ collectionView: NSCollectionView, itemForRepresentedObjectAt indexPath: IndexPath) -> NSCollectionViewItem {
        let item = collectionView.makeItem(withIdentifier: NSUserInterfaceItemIdentifier("CollectionViewItem"), for: indexPath)
        return item
    }
}
// 设置选择的样式
extension NSCollectionViewDelegate {
    func collectionView(_ collectionView: NSCollectionView, didSelectItemsAt indexPaths: Set) {
        for indexPath in indexPaths {
            if let item = collectionView.item(at: indexPath) {
                item.view.wantsLayer = true
                item.view.layer?.backgroundColor = NSColor.blue.cgColor
            }
        }
    }
    
    func collectionView(_ collectionView: NSCollectionView, didDeselectItemsAt indexPaths: Set) {
        for indexPath in indexPaths {
            if let item = collectionView.item(at: indexPath) {
                item.view.wantsLayer = true
                item.view.layer?.backgroundColor = NSColor.clear.cgColor
            }
        }
    }
}
// 创建 NSCollectionView
let collectionView = NSCollectionView(frame: NSRect(x: 0, y: 0, width: 200, height: 200))
collectionView.dataSource = CollectionViewDataSource()
collectionView.delegate = collectionView
// 设置布局
let layout = NSCollectionViewFlowLayout()
collectionView.collectionViewLayout = layout
// 添加到视图层级中
view.addSubview(collectionView)