Can XAML “deduce” inheritance from C#?

Question

I wonder if XAML is somehow able to "deduce" the C# inheritance. Let me explain:

I have these two C# classes:

public class AStyleSelector: StyleSelector {
public Style aStyle { get; set; }

public override Style SelectStyle(object item, DependencyObject container)
{
    //....
}

}

public class BStyleSelector : AStyleSelector{
public Style bStyle { get; set; }

public override Style SelectStyle(object item, DependencyObject container)
{
    var tmp = aStyle; // this is null
    //....
}

}
BStyleSelector inherits from AStyleSelector which inherits from StyleSelector. They both implement SelectStyle.

Then I have the next in a XAML file: Here I defined two styles:

<Style // to be used in both AStyleSelector and BStyleSelector
x:Key="StyleA"
//... some styles
</Style>

<Style // to be used only in BStyleSelector
x:Key="StyleB"
//... some styles
</Style>
Here I am binding to C# classes and pointing to the defined Styles:

<AStyleSelector //pointing to the above C# class
aStyle="{StaticResource StyleA}" />

<BStyleSelector //pointing to the above C# class"
bStyle="{StaticResource StyleB}" />
Now, the problem is, in the method SelectStyle from BStyleSelector, I cannot access the value of aStyle. It is returning null.

I know there is a quick fix (that works correctly) which is this:

<BStyleSelector
aStyle="{StaticResource StyleA}" // adding this line
bStyle="{StaticResource StyleB}" />
But I don't want to reference twice the StyleA. I was expecting that XAML would deduce it's value because BStyleSelector inherits it from AStyleSelector.

Is there some way to do this?

Thanks a lot in advance.

Answer 1

You can make the StyleB base on StyleA as below:

  <Style x:key="StyleB" BasedOn="{StaticResource StyleA}" TargetType="BStyleSelector">  
        <!-- Some other Style -->  
   </Style>    

Then use it like

<BStyleSelector bStyle="{StaticResource StyleB}" />  

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