Dictionarys in XAML

Short and simple post about how to declare and bind to a custom dictionary in Silverlight 4.  I had trouble finding a solid example of this since it has been properly introduced in the full release of Silverlight this past week.

Essentially I derived from Dictionary<String,String> and called it CustomDictionary within the application project.  Add a namespace declaration called local for the project and then:

<UserControl.Resources>
        <local:CustomDictionary x:Name="dictionary">
            <sys:String x:Key="One">1</sys:String>
            <sys:String x:Key="Two">2</sys:String>
            <sys:String x:Key="Three">3</sys:String>
        </local:CustomDictionary >
    </UserControl.Resources>

    <Grid>
        <TextBlock Text="{Binding Source={StaticResource dictionary}, Path=[One]}"></TextBlock>
    </Grid>

Quite simple really.  You bind to the dictionary resource and specify the key as the path.

Why do this?  I really like the idea of creating a dynamic and blendable ViewModel locator (thanks John Papa http://bit.ly/b11pUB) and I wanted to try my hand at doing this myself without the converter.

I’m planning on posting a blog on using MEF for composition and DI soon.  I think for smaller projects, it makes sense to keep it simple.  For larger projects, Unity might make more sense.