F# Silverlight, XAML and opening local files

I’m working through more examples in the book Silverlight 2 Recipes.  While it has been an interesting exercise to manually convert the XAML examples into F# code, it detracted me from learning about other aspects of Silverlight technology.  In this particular sample code, I decided to take the XAML output and dynamically load it as per the example from recipe 2-5.  Of course, once you load the UI controls via XAML, you’ll need to find those controls as per example from recipe 2-3 from the book.  Finally, the recipe I really wanted to develop is recipe 2-7 where the Silverlight app loads local files.  Below is the sample code:

#light
namespace SilverLightFSharp

open System
open System.IO
open System.IO.IsolatedStorage
open System.Windows
open System.Windows.Controls
open System.Windows.Media
open System.ServiceModel
open System.Windows.Markup
open System.Windows.Browser
open List

// Combining recipes 2-3,2-5 and 2-7 from Silverlight 2 Recipes book
// Dynamically loading XAML from managed code
// Find an element in XAML
// Opening local files
type MyPage() = class
    inherit UserControl()
    
    do
        let xaml = 
            "<Grid xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
                   xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
                   xmlns:d='http://schemas.microsoft.com/expression/blend/2008'
                   xmlns:mc='http://schemas.openxmlformats.org/markup-compatibility/2006'
                   mc:Ignorable='d'>
                <Grid.Background>
                  <LinearGradientBrush EndPoint='0.5,1' StartPoint='0.5,0'>
                    <GradientStop Color='#FF000000'/>
                    <GradientStop Color='#FFFFFFFF' Offset='1'/>
                  </LinearGradientBrush>
                </Grid.Background>
                <Grid.RowDefinitions>
                  <RowDefinition Height='0.117*'/>
                  <RowDefinition Height='0.79*'/>
                  <RowDefinition Height='0.093*'/>
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                  <ColumnDefinition Width='0.058*'/>
                  <ColumnDefinition Width='0.252*'/>
                  <ColumnDefinition Width='0.64*'/>
                  <ColumnDefinition Width='0.05*'/>
                </Grid.ColumnDefinitions>
                <Button Height='28.9' HorizontalAlignment='Stretch' Margin='8,8,11,0'
                 VerticalAlignment='Top' Width='81.8' Grid.Column='1' Grid.Row='1'
                 Content='Select Files' d:LayoutOverrides='Height' x:Name='ButtonSelectFiles'/>
                <TextBlock Margin='4,2,2,2' Grid.Column='1' Grid.Row='2' Text='Status'
                   TextWrapping='Wrap' Grid.ColumnSpan='2' x:Name='StatusLabel'/>
                <Border Grid.Column='2' Grid.Row='1' Margin='0,0,0,0' CornerRadius='12'>
                  <Border.Background>
                    <LinearGradientBrush EndPoint='0.916999995708466,0.0890000015497208'
                       StartPoint='-0.0489999987185001,2.12400007247925'>
                      <GradientStop Color='#FF1D351E'/>
                      <GradientStop Color='#FF1D351E' Offset='1'/>
                      <GradientStop Color='#FFB7D8BA' Offset='0.50900000333786011'/>
                    </LinearGradientBrush>
                  </Border.Background>
                  <ListBox x:Name='FileList' Foreground='#FF000000' Height='217'
                    Width='236' Opacity='1'/>
                </Border>
              </Grid>"

        // Load xaml dynamically        
        let grid = XamlReader.Load(xaml) :?> Grid
        
        // Find the controls...
        let status = grid.FindName("StatusLabel") :?> TextBlock
        let btnSelect = grid.FindName("ButtonSelectFiles") :?> Button
        let fileslist = grid.FindName("FileList") :?> ListBox
        
        //  open local files
        btnSelect.Click.Add(fun e -> 
            let fileDlg = new OpenFileDialog(Filter="Image Files (*.jpg)|*.jpg|All Files (*.*)|*.*",
                                             Multiselect=true,
                                             FilterIndex=1)
                                             
            let (=?!) (x: Nullable<'a>) (y:'a) = x.HasValue && x.Value = y                                             
            
            if (fileDlg.ShowDialog() =?! true )             
            then let files = fileDlg.Files
                 status.Text <- (files |> Seq.length |> sprintf "%i file(s) selected")
                 files |> Seq.iter (fileslist.Items.Add)
            )
        
        base.Width <- 400.0
        base.Height <- 300.0
        base.Content <- grid
       
       
end


type MyApp = class
    inherit Application
    
    new () as this = {} then
        this.Startup.Add(fun _ -> this.RootVisual <- new MyPage())            
        //base.Exit.Add( fun _ -> ()) //this.Application_Exit)
        //this.InitializeComponent()
end