Silverlight 3 - Creating Custom Objects inside a Merged ResourceDictionary
- by Tony Heupel
I have custom classes that I currently instantiate within App.xaml as resources. I want to move these custom objects into a Merged ResourceDictionary, where they are used within styles, and keep them close to where they are used.
Here's an example of what I want, arbitrarily using fake converter objects, but they could be any custom object...
App.xaml (namespace declarations ommitted):
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Merged.xaml" />
</ResourceDictionary.MergedDictionaries>
<Style x:Key="SomeStyle" TargetType="SomeControl">
...
</Style>
...
</ResourceDictionary>
And then in Merged.xaml (namespace declarations omitted):
<ResourceDictionary>
<cvt:VisibilityToBoolConverter x:Key="BoolToVisibility" Inverted="True"/>
<cvt:VisibilityToBoolConverter x:Key="NotBoolToVisibility" Inverted="True" Not="True"/>
<Style x:Key="SomethingThatUsesVisibilityToBoolConvertersStyle" TargetType="SomeOtherControl">
....
</Style>
</ResourceDictionary>
The issue I'm seeing is this: when I create the BoolToVisibility and NotBoolToVisibility objects (as well instantiating other objects that are instances of custom classes I have created) just as part Application.Resources, they are created and all the references work as expected; however, when I move these into a Merged Resource Dictionary (as I have in the sample above), I get a malformed Application exception when the Silverlight application loads.
I belive this to be an issue with how objects are instantiated differently in Merged Resource Dictionaries (I belive it is more of a lazy-load approach), but I would expect it to work nonetheless.
I am very much able to add Style objects, DataTemplates, ControlTemplates, and the like. But when I want to create instances of custom classes that are named or keyed using Xaml, it works great inside of App.xaml's Application.Resources directly and Application.Resources/ResourceDictionary as well. As soon as they are moved into a merged dictionary, it throws the exception. Is this by design? Any other ideas that work? Thanks in advance...
