If I move the application resources to a UserControl resources everythgin runs groovy. I still don't understand why.

I noticed that my application object MyApp did more than inherit from Application it loaded an XAML for the main template and connected all the plumbing. So I decided to create a user control to remove the template from the applciation (thinking there may be an even order issue not allowing my resource to be found).

namespace Module1

type Template() as this =
    //inherit UriUserControl("/FSSilverlightApp;component/template.xaml", "")
    inherit UriUserControl("/FSSilverlightApp;component/templateSimple.xaml", "")
    do
        Application.LoadComponent(this, base.uri)

    let siteTemplate : Grid = (this.Content :?> FrameworkElement) ? siteTemplate
    let nav : Frame = siteTemplate ?  contentFrame


    let pages : UriUserControl array = [|
        new Module1.Page1() :> UriUserControl ;
        new Module1.Page2() :> UriUserControl ;
        new Module1.Page3() :> UriUserControl ;
        new Module1.Page4() :> UriUserControl ; 
        new Module1.Page5() :> UriUserControl ; |]

    do
        nav.Navigate((pages.[0] :> INamedUriProvider).Uri)  |> ignore

type MyApp() as this =
    inherit Application() 
        do Application.LoadComponent(this, new System.Uri("/FSSilverlightApp;component/App.xaml", System.UriKind.Relative))      
    do
        System.Windows.Browser.HtmlPage.Plugin.Focus()
        this.RootVisual <- new Template() ;

    // test code to check for the existance of the ControlTemplate - it exists
        let a = Application.Current.Resources.MergedDictionaries
        let b  = a.[0]
        let c = b.Count
        let d : ControlTemplate = downcast c.["TransitioningFrame"]
        ()

"/FSSilverlightApp;component/templateSimple.xaml"

<UserControl x:Class="Module1.Template"
        xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation"  
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >

    <Grid  HorizontalAlignment="Center" Background="White"
        Name="siteTemplate">

        <StackPanel Grid.Row="3" Grid.Column="2" Name="mainPanel">
            <!--Template="{StaticResource TransitioningFrame}"-->
            <navigation:Frame Name="contentFrame" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Template="{StaticResource TransitioningFrame}"/>
        </StackPanel>

    </Grid>
</UserControl>

"/FSSilverlightApp;component/App.xaml"

<Application xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
             x:Class="Module1.MyApp">
    <Application.Resources>
         <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="/FSSilverlightApp;component/TransitioningFrame.xaml" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

"/FSSilverlightApp;component/TransitioningFrame.xaml"

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation"  
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <ControlTemplate x:Key="TransitioningFrame" TargetType="navigation:Frame">
        <Border Background="Olive"
                BorderBrush="{TemplateBinding BorderBrush}"
                BorderThickness="5"
                HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
            <ContentPresenter Cursor="{TemplateBinding Cursor}"
                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                          Margin="{TemplateBinding Padding}"
                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                          Content="{TemplateBinding Content}"/>
        </Border>
    </ControlTemplate>
</ResourceDictionary>

Unfortunately that did not work. If I remove the template attribute from the navigationFrame element, the app loads and directs the content area to the first page in the pages array. Referencing that resource continues to throw a resource no found error.

Original Post

I have the following app.xaml (using Silverlight 3)

<Application xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
             x:Class="Module1.MyApp">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="/FSSilverlightApp;component/TransitioningFrame.xaml" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

and content template:

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation"  
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <ControlTemplate x:Key="TransitioningFrame" TargetType="navigation:Frame">
        <Border Background="{TemplateBinding Background}"
                BorderBrush="{TemplateBinding BorderBrush}"
                BorderThickness="{TemplateBinding BorderThickness}"
                HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
            <ContentPresenter Cursor="{TemplateBinding Cursor}"
                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                          Margin="{TemplateBinding Padding}"
                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                          Content="{TemplateBinding Content}"/>
        </Border>
    </ControlTemplate>
</ResourceDictionary>

The debugger says it the contentTemplate is loaded correctly by adding some minimal code:

type MyApp() as this = inherit Application() do Application.LoadComponent(this, new System.Uri("/FSSilverlightApp;component/App.xaml", System.UriKind.Relative))

let cc = new ContentControl()
let mainGrid : Grid = loadXaml("MainWindow.xaml")

do
    this.Startup.Add(this.startup)

    let t = Application.Current.Resources.MergedDictionaries
    let t1  = t.[0]
    let t2 = t1.Count
    let t3: ControlTemplate = t1.["TransitioningFrame"]

With this line in my main.xaml

<navigation:Frame Name="contentFrame" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"  Template="{StaticResource TransitioningFrame}"/>

Yields this exception

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.2; .NET4.0C; .NET4.0E) Timestamp: Mon, 24 May 2010 23:10:15 UTC

Message: Unhandled Error in Silverlight Application Code: 4004
Category: ManagedRuntimeError
Message: System.Windows.Markup.XamlParseException: Cannot find a Resource with the Name/Key TransitioningFrame [Line: 86 Position: 115] at MS.Internal.XcpImports.CreateFromXaml(String xamlString, Boolean createNamescope, Boolean requireDefaultNamespace, Boolean allowEventHandlers, Boolean expandTemplatesDuringParse) at MS.Internal.XcpImports.CreateFromXaml(String xamlString, Boolean createNamescope, Boolean requireDefaultNamespace, Boolean allowEventHandlers) at System.Windows.Markup.XamlReader.Load(String xaml) at Globals.loadXaml[T](String xamlPath) at Module1.MyApp..ctor()

Line: 54 Char: 13 Code: 0 URI: file:///C:/fsharp/FSSilverlightDemo/FSSilverlightApp/bin/Debug/SilverlightApplication2TestPage.html