NSOutlineView 示例

一篇关于NSOutlineView的文章。

swift
import Cocoa
class ViewController: NSViewController, NSOutlineViewDataSource, NSOutlineViewDelegate {
    @IBOutlet weak var outlineView: NSOutlineView!
    override func viewDidLoad() {
        super.viewDidLoad()
        outlineView.dataSource = self
        outlineView.delegate = self
    }
    // 实现数据源方法
    func outlineView(_ outlineView: NSOutlineView, numberOfChildrenOfItem item: Any?) -> Int {
        // 返回根节点的子节点数量
        if item == nil {
            return 3
        }
        // 返回当前节点的子节点数量
        if let node = item as? Node {
            return node.children.count
        }
        return 0
    }
    func outlineView(_ outlineView: NSOutlineView, child index: Int, ofItem item: Any?) -> Any {
        // 返回根节点的子节点
        if item == nil {
            return Node(name: "Root", children: [
                Node(name: "Child 1"),
                Node(name: "Child 2"),
                Node(name: "Child 3")
            ])
        }
        // 返回当前节点的子节点
        if let node = item as? Node {
            return node.children[index]
        }
        return Node(name: "")
    }
    func outlineView(_ outlineView: NSOutlineView, isItemExpandable item: Any) -> Bool {
        // 判断当前节点是否可展开
        if let node = item as? Node {
            return node.children.count > 0
        }
        return false
    }
    func outlineView(_ outlineView: NSOutlineView, viewFor tableColumn: NSTableColumn?, item: Any) -> NSView? {
        // 返回节点对应的视图
        if let node = item as? Node {
            let view = outlineView.makeView(withIdentifier: NSUserInterfaceItemIdentifier(rawValue: "DataCell"), owner: self) as! NSTableCellView
            view.textField?.stringValue = node.name
            return view
        }
        return nil
    }
    // 实现委托方法
    func outlineViewSelectionDidChange(_ notification: Notification) {
        // 处理节点选择变化事件
        let selectedIndex = outlineView.selectedRow
        if selectedIndex >= 0 {
            let selectedItem = outlineView.item(atRow: selectedIndex)
            if let node = selectedItem as? Node {
                print("Selected item: \(node.name)")
            }
        }
    }
}
struct Node {
    var name: String
    var children: [Node] = []
}