Yes, this is possible. For example:
<Style TargetType="TextBlock">
<Setter Property="FontSize">
<Setter.Value>
<Binding Path="ActualHeight" RelativeSource="{RelativeSource Self}">
<Binding.Converter>
<MyConverter/>
</Binding.Converter>
</Binding>
</Setter.Value>
</Setter>
</Style>
Depending on your exact scenario, you might also be able to use the more succinct:
<Style TargetType="TextBlock">
<Setter Property="FontSize" Value="{Binding ActualHeight, RelativeSource={RelativeSource Self}, Converter={StaticResource MyConverter}}"/>
</Style>
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…