open System
open System.Windows
open System.Threading
open System.Timers
open FsXaml

type WpfBuilder(ui:UIElement)=
    let disp=ui.Dispatcher
    let Fn (fn:(unit-> 'a))=new Func<'a>(fn)|>disp.Invoke
//    let Fn (fn:(unit-> 'a))=new Func<'a>(fn)|>disp.Invoke :?> 'a //for old F#/ .Net framework versions
    member ob.Zero()=()
    member ob.Delay(fn)=Fn fn
    member ob.Return(x)=(fun _ ->x)|>Fn

type Winr=XAML<"MainForm.xaml">

let win=new Winr()
let wpf=new WpfBuilder(win)

let tmr=new Timer(2000.0,Enabled=true)
tmr.Elapsed.Add(fun _->let head=wpf{let h=win.Title
                                    win.Title<-h+"..."
                                    return h}
                       Thread.Sleep(1000)
                       wpf{win.Title<-head+"."})

let app=new Application()
[<STAThread>]
app.Run(win)|>ignore