KeyedCollection and d:DataContext Design Error

Question

See the update below for VS2013.

When using a class as a d:DesignInstance that exposes a KeyedCollection, the XAML desig

Answer 1

If I have'nt misunderstood your question try it like

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
            xmlns:local="clr-namespace:WpfApplication1"
    Width="800" Height="800"
    Title="MainWindow"   
    >
<Window.DataContext>
    **<local:MyClass />**
</Window.DataContext>
<Grid x:Name="LayoutRoot">
</Grid>

I hope this will help.

Answer 2

I had to remove the Default Constructor from my DesignInstance-Class

Answer 3

I've been able to resolve this issue by prefixing the design instance type with "d:Type" as such:

d:DataContext="{d:DesignInstance d:Type=local:MyClass}"

This seems to be a bug in the VS2013 designer. I believe the d:Type property should be the default property of the d:DesignInstance attribute. Also, strangely I've only seen this issue with the KeyedCollection class.

Furthermore, the MSDN examples of d:DesignInstance usage sometimes use "Type" with no prefix. In this example if d:Type is omitted or the prefix is missing, the design time error is generated as I mentioned.