f# - 如何使用 F# 创建多级 TreeView？

Question

我想通过 F# 使用 Gtk# 小部件显示目录结构，但我很难弄清楚如何将 TreeViews 转换为 F#。假设我有一个如下所示的目录结构:

Directory1
  SubDirectory1
  SubDirectory2
    SubSubDirectory1
  SubDirectory3
Directory2

如何使用 F# 通过 Gtk# 小部件显示此树结构？

编辑:

gradbot 是我所希望的答案，但有几个异常(exception)。如果您使用 ListStore，您将失去扩展级别的能力，如果您改为使用:

let musicListStore = new Gtk.TreeStore([|typeof<String>; typeof<String>|])

您将获得具有可扩展级别的布局。但是，这样做会中断对 AppendValues 的调用，因此您必须为编译器添加一些线索来确定要使用哪个重载方法:

musicListStore.AppendValues (iter, [|"Fannypack" ; "Nu Nu (Yeah Yeah) (double j and haze radio edit)"|])

请注意，列是作为数组显式传递的。

最后，您可以使用 Append Values 返回的 ListIter 进一步嵌套级别

let iter = musicListStore.AppendValues ("Dance")
let subiter = musicListStore.AppendValues (iter, [|"Fannypack" ; "Nu Nu (Yeah Yeah) (double j and haze radio edit)"|])
musicListStore.AppendValues (subiter, [|"Some Dude"; "Some Song"|]) |> ignore

Answer 1

我不太确定您在寻找什么，但这是来自他们的 tutorials 的翻译示例。它可能会帮助您入门。图片取自tutorial site .

我认为多级 TreeView 的关键是将值附加到值，iter 在这一行 musicListStore.AppendValues (iter, "Fannypack", "Nu Nu (Yeah Yeah) (双 j 和雾霾 radio 编辑)") |> 忽略

// you will need to add these references gtk-sharp, gtk-sharp, glib-sharp 
// and set the projects running directory to 
// C:\Program Files (x86)\GtkSharp\2.12\bin\

module SOQuestion

open Gtk
open System

let main() =
    Gtk.Application.Init()

    // Create a Window
    let window = new Gtk.Window("TreeView Example")
    window.SetSizeRequest(500, 200)

    // Create our TreeView
    let tree = new Gtk.TreeView()
    // Add our tree to the window
    window.Add(tree)

    // Create a column for the artist name
    let artistColumn = new Gtk.TreeViewColumn()
    artistColumn.Title <- "Artist"

    // Create the text cell that will display the artist name
    let artistNameCell = new Gtk.CellRendererText()
    // Add the cell to the column
    artistColumn.PackStart(artistNameCell, true)

    // Create a column for the song title
    let songColumn = new Gtk.TreeViewColumn()
    songColumn.Title <- "Song Title"

    // Do the same for the song title column
    let songTitleCell = new Gtk.CellRendererText()
    songColumn.PackStart(songTitleCell, true)

    // Add the columns to the TreeView
    tree.AppendColumn(artistColumn) |> ignore
    tree.AppendColumn(songColumn) |> ignore

    // Tell the Cell Renderers which items in the model to display
    artistColumn.AddAttribute(artistNameCell, "text", 0)
    songColumn.AddAttribute(songTitleCell, "text", 1)

    let musicListStore = new Gtk.ListStore([|typeof<String>; typeof<String>|])

    let iter = musicListStore.AppendValues ("Dance")
    musicListStore.AppendValues (iter, "Fannypack", "Nu Nu (Yeah Yeah) (double j and haze radio edit)") |> ignore

    let iter = musicListStore.AppendValues ("Hip-hop")
    musicListStore.AppendValues (iter, "Nelly", "Country Grammer") |> ignore

    // Assign the model to the TreeView
    tree.Model <- musicListStore

    // Show the window and everything on it
    window.ShowAll()

    // add event handler so Gtk will exit
    window.DeleteEvent.Add(fun _ -> Gtk.Application.Quit())

    Gtk.Application.Run()

[<STAThread>]
main()