WPF MultiBinding same converter with different binding path - wpf

Question

I have ten UI Controls of the same type in a UI and all will be using same multi binding converter.
The problem is I can not create a common style for multibinding which I can apply to all UI controls to avoid duplicate code, as each control will use a different binding property to pass as a Binding to converter.
Is there any way in WPF we can avoid duplicate code for this scenario?

Answer 1

You can extend MarkupExtension, which allows you to define a custom Converter wrapper and then just call it with the 2 Paths.
Edit: in your case it's probably best to inherit directly from MultiBinding and set sensible defaults in the constructor.

Answer 2

I assume you have something like this:
<Button>
<Button.Content>
<MultiBinding Converter="{StaticResource conv}">
<Binding Path="COMMON" />
<Binding Path="SPECIFIC1" />
</MultiBinding>
</Button.Content>
</Button>
<Button>
<Button.Content>
<MultiBinding Converter="{StaticResource conv}">
<Binding Path="COMMON" />
<Binding Path="SPECIFIC2" />
</MultiBinding>
</Button.Content>
</Button>
<Button>
<Button.Content>
<MultiBinding Converter="{StaticResource conv}">
<Binding Path="COMMON" />
<Binding Path="SPECIFIC3" />
</MultiBinding>
</Button.Content>
</Button>
and so on...
this looks ugly, I agree.
I am not aware of any alternatives, however by thinking a little, you could create(imo) a little better solution:
just create new CommonMultiBindings.xaml;
which includes:
<MultiBinding Converter="{StaticResource conv}">
</MultiBinding>
and voila, done. Now just reference it as CommonMultiBindings object and use it as:
<Button.Content>
<CommonMultiBindings>
<!--Actual bindings here-->
</CommonMultiBindings>
</Button.Content>
you can take it further by factoring "" into the CommonMultiBindings and adding new property(UserBindings) which will be used to synchronize between Bindings property.
Ideally, you would want to create a custom MultiBinding class which has style property. Then you could do something like this + combined with "custom" default bindings which are automatically added to "Bindings" collection
<Grid.Resources>
<Style TargetType="MultiBinding">
<Setter Property="Converter" Value="{StaticResource conv}" />
</Style>
</Grid.Resources>