Silverlight 3 IValueConverter troubles

First let me say I'm new to Silverlight. But I have most of the "basic" Silverlight stuff figured out. I'm using Silverlight 3 at the moment.

In a nutshell, I am not seeing my IValueConverter called inside a UserControl. But as with many things, it's not quite that simple. The UserControl is in a DataGrid cell, in a column whose DataColumnTemplate is generated at runtime by XAML.

Here's my DataTemplate for the Column:

StringBuilder CellTemp = new StringBuilder();
            CellTemp.Append("<DataTemplate ");
            CellTemp.Append("xmlns:aa='clr-namespace:InvTech.AA.Silverlight.UI;assembly=AASilverlight' ");            
            CellTemp.Append("xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' ");
            CellTemp.Append("xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' ");
            CellTemp.Append(">");
            CellTemp.AppendFormat("<aa:ProductAssetView DataContext='{{Binding Products[{0}]}}' />", index);
            CellTemp.Append("</DataTemplate>");
  开发者_如何学Python          return CellTemp.ToString();

So the cell's contents are getting bound to my UserControl. This works; I just can't get my IValueConverter called to format the contents of the UserControl the way I want.

The operative parts of the UserControl XAML:

(declare prefix)

xmlns:aaConv="clr-namespace:InvTech.AA.Silverlight.Core;assembly=AA.Core"

(bound controls inside Grid layout)

<TextBox x:Name="txtSAA" Grid.Row="0" Grid.Column="0" Text="{Binding SAA, Converter={StaticResource PercentConverter}, Mode=TwoWay}"  Width="35" FontSize="9"/>
<TextBox x:Name="txtOVR" Grid.Row="0" Grid.Column="1" Text="{Binding Overlay, Converter={StaticResource PercentConverter}, Mode=TwoWay}" Width="35" FontSize="9" />
<TextBox x:Name="txtTAA" Grid.Row="0" Grid.Column="2" Text="{Binding TAA, Converter={StaticResource PercentConverter}, Mode=TwoWay}" Width="35" FontSize="9" />
<TextBlock x:Name="tbkCurrent" Grid.Row="0" Grid.Column="3" Text="TODO" Width="35" FontSize="9"  />            
<Grid.Resources>
     <aaConv:PercentValueConverter x:Key="PercentConverter" />
</Grid.Resources>

Is there something obviously wrong here? Is the dynamic XAML a factor? I feel like this should be trivial compared to the dynamic XAML template...

Thanks

Finally figured this out. By moving the Resource declaration to <UserControl.Resources> and putting that tag before the content, my IValueConverters were exercised.