Fix Accessibility test application: Screenreader does not read ListItem contents in DataBindingDemo

[ryalanms]

Guy Barker's fix for Accessibility Bug 1144842: A11y_.NETCore_DatabindingDemo_List of Products_Screenreader: Screenreader does not read the text content written on the list present (Elecronics,Sports and Books)

[rladuca]

This is a strange one. I have some issue with just using the name, when there is something like checked/unchecked available assuming the correct UIA representation of the star itself. However, there is no real way of changing checked/unchecked w.r.t. to narrator to say something like "starred" or "featured", so this is probably the best compromise. Better would be some way of configuring the text relayed from something implementing the TogglePattern. obviously beyond the scope of this.

[SamBent]

Don't use ToString for this. It breaks MVVM (by putting View information in the Model), and doesn't work in general. For instance if the app had another view of an AuctionItem, or if the AuctionItem class wasn't owned by the app, you couldn't do this.

Instead set the Name property in the View, matching the visual described by that view as appropriate. The mechanics to do this: 1) declare (or add to an existing) ItemContainerStyle for the ListBox, 2) set the AutomationProperties.Name attached property in that style, 3) use data-binding to make the name depend on the data item, 4) use multi-binding if the name depends on several properties, and a converter to piece them all together.

Sketch:

<ListBox.ItemContainerStyle>
  <Style TargetType="ListBoxItem">
     <Setter Property="AutomationProperties.Name">
         <Setter.Value>
             <MultiBinding Converter="{StaticResource.MyConverter}">
                <Binding Path="SpecialFeatures"/>
                <Binding Path="Description"/>
                <Binding Path="CurrentPrice"/>
 ///>

MyConverter.Convert(object[] values, ...)
{
   SpecialFeatures specialFeatures = ...convert values[0] to SpecialFeatures...;
   string description = values[1] as string;
   double currentPrice = values[2] as double;
   return   ... Guy's code ... ;
}