如何用Swift在NSAlert的accessoryView中嵌入NSTableView

问题原因 #

你的代码中所有自动布局约束都被注释，导致各级控件没有正确的尺寸和位置规则，无法正常渲染：

• 根容器view没有设置固定宽高，NSAlert无法正确计算accessoryView的占位大小
• scrollView没有和根容器view做约束绑定，尺寸无法正确适配父容器
• 单元格内的文本控件没有约束，不会显示内容

修正后完整代码 #

#!/usr/bin/env swift

import AppKit
import Foundation

let app = NSApplication.shared
app.setActivationPolicy(.regular) // 用于接收键盘输入且在程序坞显示

class TableViewController: NSViewController, NSTableViewDelegate, NSTableViewDataSource {

    var initialized = false
    let scrollView = NSScrollView(frame: NSRect(x: 0, y: 4, width: 200, height: 300))
    let tableView = NSTableView(frame: NSRect(x: 0, y: 4, width: 200, height: 300))

    override func loadView() {
        print("Load view")
        // 直接给根view设置初始尺寸
        self.view = NSView(frame: NSRect(x: 0, y: 0, width: 200, height: 300))
    }

    override func viewDidLoad() {
        print("Did load")
        super.viewDidLoad()
        setupView()
        setupTableView()
    }

    func setupView() {
        print("setupView")
        self.view.translatesAutoresizingMaskIntoConstraints = false
        // 给根view设置固定宽高
        self.view.addConstraint(NSLayoutConstraint(item: self.view, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 200))
        self.view.addConstraint(NSLayoutConstraint(item: self.view, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 300))
    }

    func setupTableView() {
        print("setupTableView")
        self.view.addSubview(scrollView)
        self.scrollView.translatesAutoresizingMaskIntoConstraints = false
        // 绑定scrollView和父容器的四边约束
        self.view.addConstraint(NSLayoutConstraint(item: self.scrollView, attribute: .left, relatedBy: .equal, toItem: self.view, attribute: .left, multiplier: 1.0, constant: 0))
        self.view.addConstraint(NSLayoutConstraint(item: self.scrollView, attribute: .top, relatedBy: .equal, toItem: self.view, attribute: .top, multiplier: 1.0, constant: 0))
        self.view.addConstraint(NSLayoutConstraint(item: self.scrollView, attribute: .right, relatedBy: .equal, toItem: self.view, attribute: .right, multiplier: 1.0, constant: 0))
        self.view.addConstraint(NSLayoutConstraint(item: self.scrollView, attribute: .bottom, relatedBy: .equal, toItem: self.view, attribute: .bottom, multiplier: 1.0, constant: 0))
        tableView.frame = scrollView.bounds
        tableView.delegate = self
        tableView.dataSource = self
        tableView.headerView = nil
        scrollView.backgroundColor = NSColor.clear
        scrollView.drawsBackground = false
        tableView.backgroundColor = NSColor.clear
        tableView.appearance = NSAppearance(named: NSAppearance.Name.vibrantDark)

        let col = NSTableColumn(identifier: NSUserInterfaceItemIdentifier(rawValue: "col"))
        col.minWidth = 200
        tableView.addTableColumn(col)

        scrollView.documentView = tableView
        scrollView.hasHorizontalScroller = false
        scrollView.hasVerticalScroller = true
        
        tableView.reloadData()
    }

    func numberOfRows(in tableView: NSTableView) -> Int {
        return 100
    }

    func tableView(_ tableView: NSTableView, viewFor tableColumn: NSTableColumn?, row: Int) -> NSView? {
        let text = NSTextField()
        text.stringValue = "Hello World \(row + 1)"
        let cell = NSTableCellView(frame: NSRect(x: 0, y: 0, width: 200, height: 20))
        cell.addSubview(text)
        text.drawsBackground = false
        text.isBordered = false
        text.translatesAutoresizingMaskIntoConstraints = false
        // 打开文本控件的约束
        cell.addConstraint(NSLayoutConstraint(item: text, attribute: .centerY, relatedBy: .equal, toItem: cell, attribute: .centerY, multiplier: 1, constant: 0))
        cell.addConstraint(NSLayoutConstraint(item: text, attribute: .left, relatedBy: .equal, toItem: cell, attribute: .left, multiplier: 1, constant: 13))
        cell.addConstraint(NSLayoutConstraint(item: text, attribute: .right, relatedBy: .equal, toItem: cell, attribute: .right, multiplier: 1, constant: -13))
        return cell
    }

    func tableView(_ tableView: NSTableView, rowViewForRow row: Int) -> NSTableRowView? {
        let rowView = NSTableRowView()
        rowView.isEmphasized = false
        return rowView
    }
    
    func tableView(_ tableView: NSTableView, heightOfRow row: Int) -> CGFloat {
        return 22
    }

}

func runOptionsDialog(args: [String]) {
    let title = args[0]
    let text = args[1]
    let okButton = args[2]
    let cancelButton = args[3]

    let a = NSAlert()
    a.messageText = title
    a.alertStyle = NSAlert.Style.warning
    a.informativeText = text
    a.addButton(withTitle: okButton)
    a.addButton(withTitle: cancelButton)

    let con = TableViewController()
    a.accessoryView = con.view

    app.activate(ignoringOtherApps: true)
    a.runModal()
}

runOptionsDialog(args:["title", "whast", "ok", "cancel"])

运行说明 #

直接执行swift table.swift即可看到弹窗中正常显示带滚动条的列表，100行带行号的文本可正常滚动查看。

内容的提问来源于stack exchange，提问作者Gabriel