// The button stacking example.
module Avalonia.Try3
module UI =
open Avalonia
open Avalonia.Media
open Avalonia.Controls
open Avalonia.Layout
open System
open System.Reactive
open System.Reactive.Linq
open System.Reactive.Disposables
open System.Reactive.Concurrency
open System.Reactive.Subjects
/// Lithe
let do' f c = f c; Disposable.Empty
let prop s v c = Observable.subscribe (s c) v
let prop_set (p : 'a AvaloniaProperty) (v : 'a IObservable) (c : #Control) = v.Subscribe(fun v -> c.SetValue(p,v))
let prop_change<'a,'c when 'c :> Control> (p : 'a AvaloniaProperty) f (c : 'c) = c.GetPropertyChangedObservable(p).Subscribe(fun x -> f c (x.NewValue :?> 'a))
let event s f c = (s c : IEvent<_,_>).Subscribe(fun v -> f c v)
let control<'a when 'a :> Control> (c : unit -> 'a) l =
Observable.Create (fun (obs : IObserver<_>) ->
let c = c()
let d = Seq.map ((|>) c) l
obs.OnNext (c :> Control)
new CompositeDisposable(d) :> IDisposable
)
let children_template (l : Control IObservable seq) (c : Controls) =
l |> Seq.mapi (fun i v -> v.Subscribe (fun v -> if i < c.Count then c.[i] <- v else c.Add v))
|> fun x -> new CompositeDisposable(x) :> IDisposable
let children l (c : #Panel) = children_template l c.Children
let content v c = prop (fun (x : #ContentControl) v -> x.Content <- v) v c
let child v c = prop (fun (x : #Decorator) v -> x.Child <- v) v c
let window l = control Window l
let button l = control Button l
let stack_panel l = control StackPanel l
let dock_panel l = control DockPanel l
let slider l = control Slider l
let text_block l = control TextBlock l
let border l = control Border l
let separator l = control Separator l
let check_box l = control CheckBox l
/// Example
type Messages =
| SliderChanged of int
type Model = {num_buttons : int }
let init = {num_buttons = 3}
let pump = Subject.Synchronize(Subject(), Avalonia.Threading.AvaloniaScheduler.Instance)
let dispatch msg = pump.OnNext msg
let update =
pump.Scan(init, fun model msg ->
match msg with
| SliderChanged(n) -> {model with num_buttons=n}
)
.Publish(init)
let num_buttons = update.Select(fun x -> x.num_buttons).DistinctUntilChanged()
// Displays a message box as a dialog window
let message_box_dialog msg =
match Application.Current.ApplicationLifetime with
| :? ApplicationLifetimes.IClassicDesktopStyleApplicationLifetime as desktop ->
let d = new SingleAssignmentDisposable()
window [
do' <| fun x -> x.SizeToContent <- SizeToContent.WidthAndHeight; x.Title <- "Message"
event (fun x -> x.Closing) (fun _ _ -> d.Dispose())
content <| text_block [
do' <| fun x ->
x.Margin <- Thickness 30.0; x.FontSize <- 30.0;
x.Text <- msg
]
]
|> fun w -> d.Disposable <- w.Subscribe(fun x -> (x :?> Window).ShowDialog(desktop.MainWindow) |> ignore)
| _ -> ()
let create_buttons =
let rng = Random()
fun n ->
[0..n-1]
|> List.map (fun i ->
button [
do' <| fun btn ->
btn.Margin <- Thickness 2.0
//btn.Name <- 'A' + char i |> string // TODO: How do I set the name without wiping the content?
btn.FontSize <- rng.Next(10) |> float |> (+) btn.FontSize
btn.Content <- sprintf "Button %s says click me!" btn.Name
event (fun btn -> btn.Click) (fun btn args -> message_box_dialog <| sprintf "Button %s has been clicked!" btn.Name)
]
)
let view =
window [
do' <| fun t ->
t.MinHeight <- 300.0
t.MinWidth <- 300.0
t.WindowStartupLocation <- WindowStartupLocation.CenterScreen
t.SizeToContent <- SizeToContent.WidthAndHeight
t.Title <- "Stack Ten Buttons"
content <| stack_panel [
do' <| fun pan ->
pan.Background <- Brushes.Aquamarine
pan.Margin <- Thickness 10.0
children [
text_block [
do' <| fun x -> x.HorizontalAlignment <- HorizontalAlignment.Center
prop (fun x v -> x.Text <- v) (num_buttons.Select string)
]
slider [
do' <| fun sld ->
sld.IsSnapToTickEnabled <- true
sld.Minimum <- 0.0
sld.Maximum <- 10.0
prop (fun c v -> c.Value <- v) (num_buttons.Select float)
prop_change Slider.ValueProperty (fun _ x -> dispatch (SliderChanged (int x)))
]
num_buttons.SelectMany(fun x ->
stack_panel [
do' <| fun pan -> pan.Background <- Brushes.Red; pan.Margin <- Thickness 20.0
children <| create_buttons x
]
)
]
]
]
module Main =
open System
open Avalonia
open Avalonia.Controls
open Avalonia.Controls.ApplicationLifetimes
open Avalonia.Markup.Xaml.Styling
type App() =
inherit Application()
let d = new Reactive.Disposables.CompositeDisposable()
override x.Initialize() =
x.Styles.AddRange [
new StyleInclude(baseUri=null, Source = Uri("resm:Avalonia.Themes.Default.DefaultTheme.xaml?assembly=Avalonia.Themes.Default"))
new StyleInclude(baseUri=null, Source = Uri("resm:Avalonia.Themes.Default.Accents.BaseLight.xaml?assembly=Avalonia.Themes.Default"))
]
override x.OnFrameworkInitializationCompleted() =
match x.ApplicationLifetime with
| :? IClassicDesktopStyleApplicationLifetime as desktop ->
[
UI.view.Subscribe (fun v -> desktop.MainWindow <- v :?> Window)
UI.update.Connect()
] |> List.iter d.Add // TODO: Figure out how to dispose of this when App closes.
| _ -> ()
base.OnFrameworkInitializationCompleted()
interface IDisposable with member _.Dispose() = d.Dispose()
open Avalonia.Logging.Serilog
[<CompiledName "BuildAvaloniaApp">]
let buildAvaloniaApp () = AppBuilder.Configure<App>().UsePlatformDetect().LogToDebug()
let main argv = buildAvaloniaApp().StartWithClassicDesktopLifetime(argv)
取消注释以下行将导致上述示例无法正常运行：
//btn.Name <- 'A' + char i |> string // TODO: How do I set the name without wiping the content?
内容将被擦除，只会创建一个空按钮，并且不会响应点击事件。WPF 中的类似程序可以正常工作。该Name属性在 Avalonia 中的作用是否与在 WPF 中的作用不同？这里应该做什么？