Visual Studio Designer complianing about ObservableCollection in XAML?

Question

I have a property on an object that is exposed like this:
/// <summary>
/// A collection of images and their keys for assembling the <see cref="ImageSelector"/> controls.
/// </summary>
[ContentProperty("ImageSource")]
public class ImageDictionary
/// <summary>
/// Gets the source list of images and their keys.
/// </summary>
public ObservableCollection<ImageKeyPair> ImageSource
get
return this.sourceImagesField;
In XAML, I attempt to access it like this:
<!-- Gender Image Collection -->
<controls:ImageDictionary x:Key="GenderImages">
<controls:ImageKeyPair UriSource="pack://application:,,/Assets/Female.ico">
<localModel:Gender>Female</localModel:Gender>
</controls:ImageKeyPair>
<controls:ImageKeyPair UriSource="pack://application:,,/Assets/Male.ico">
<localModel:Gender>Male</localModel:Gender>
</controls:ImageKeyPair>
</controls:ImageDictionary>
The code works just fine, but the Visual Studio Designer is giving me an error of:
The value "Teraque.View.Controls.ImageKeyPair" is not of type "Teraque.View.Controls.ImageKeyPair" and cannot be used in this generic collection.
Any clues what's going on here?  Is there a more conventional method of exposing an ObservableCollection to XAML?

Answer 1

There is a more conventional method which is xaml friendly.
http://social.technet.microsoft.com/wiki/contents/articles/26200.aspx#ObservableCollection_of_a_Complex_Type
It sort of hinges on an odd class which inherits from a typed observablecollection:
public class ColourCollection : ObservableCollection<SimpleColour>
You can then build such a collection in xaml:
<Application.Resources>
<local:ColourCollection x:Key="ColourSource">
<local:SimpleColour ColourString="Yellow" Id="1"/>
<local:SimpleColour ColourString="Blue" Id="2"/>
<local:SimpleColour ColourString="Red" Id="3"/>
<local:SimpleColour ColourString="Green" Id="4"/>
<local:SimpleColour ColourString="Purple" Id="5"/>
</local:ColourCollection>
</Application.Resources>
Although, obviously, you will probably want to build that collection in a resource dictionary merged by app.xaml or some such.
Hope that helps.
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