Get values from *.resx files in XAML
Make sure that Code Generation is set to Public in the resx editor, then you can simply use:
<TextBlock Text="{x:Static Messages.WarningUserMessage}" />
It's a lot easier to do it like this. Add a xmlns in XAML file and use the resources directly.
xmlns:resx="clr-namespace:wpfapplicationname.Properties"
Title="{x:Static resx:Resources.name}"