Xwt + Observable.FromEventPattern<T>() in F#

gistfile1.fs

// Learn more about F# at http://fsharp.net
// See the 'F# Tutorial' project for more help.

open System
open Xwt
open System.Reactive.Linq

type MyWindow () as this =
    inherit Window ()
    do
        this.Closed.Add (fun ea -> Application.Exit ())
        let label = new Label ()
        let f = new Frame (WidthRequest = 200.0, HeightRequest = 200.0)
        let eo = Observable.FromEventPattern<MouseMovedEventArgs> (f, "MouseMoved")
        let sample = eo.Sample (TimeSpan.FromSeconds 1.0)
        sample.Subscribe (fun v -> label.Text <- v.EventArgs.Position.ToString ())
        let vb = new VBox ()
        vb.PackStart (f)
        vb.PackStart (label)
        this.Content <- vb

[<EntryPoint>]
let main argv = 
    printfn "%A" argv
    Application.Initialize ()
    let x = new MyWindow ()
    x.Show ()
    Application.Run ()
    0 // return an integer exit code