Is there a way to do simple calculations in a xaml element binding statement other than using a converter?

Question

In XAML I want to bind the height of one element to be half the height of another element. Is there a way to do this that doesn't involve writing a converter in the code-behind?

Example:- What I've got...

<Button Name="RemoveButton" Content="Remove Stage" Width="100" Height="{Binding  ElementName=AddButton, Path=Height, Converter={StaticResource MyHalfHeightConverter}}"/>

What I'd like...

<Button Name="RemoveButton" Content="Remove Stage" Width="100" Height="{Binding ElementName=AddButton, Path=(Height / 2.0)}"/>

Answer 1

I do not think there is a Binding solution without a converter. But why not use one? You will often come across a requirement like this, so it makes sense to create some sort of MathConverter which takes some properties or parameters. Then you do not need to create a separate converter for each single requirement.

However, if you really do not want to use a converter, depending on your layout you might also use a star-sized grid where the AddButton is spread across two rows while the RemoveButton only occupies one row:

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>

    <Button Name="AddButton" Grid.Row="0" Grid.RowSpan="2" ... />
    <Button Name="RemoveButton" Grid.Row="1" ... />

</Grid>

If you want the RemoveButton to be centered vertically, use this:

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="1*"/>
        <RowDefinition Height="2*"/>
        <RowDefinition Height="1*"/>
    </Grid.RowDefinitions>

    <Button Name="AddButton" Grid.Row="0" Grid.RowSpan="3" ... />
    <Button Name="RemoveButton" Grid.Row="1" ... />

</Grid>

This way, the AddButton occupies three rows (4* in total) while the RemoveButton is in the center row (2*).

If it is not possible to add them to one shared Grid, you might make use of the Grid.IsSharedSizeScope attached property. Details can be found here.