XAML : Binding FontSize to the Height of Control - xaml

Question

Within a Xamarin.Form page, I am trying to bind the FontSize of a label to the height of that same label.
I seen examples in WPF that do this:
FontSize="{Binding ElementName=CurrentPresenter, Path=Height}"
But I can not seem to get anything to work like that in Forms, i.e.:
<Label
Text="X"
FontSize="{Binding ElementName=CurrentPresenter, Path=RequestedHeight}"
HorizontalTextAlignment="Center"
AbsoluteLayout.LayoutBounds="0.1, 0.5, 0.33, 0.66"
AbsoluteLayout.LayoutFlags="All" />
(I will use a data converter to adjust the font size so based upon screen DPI, I can auto-adjust, but for now, I'm just trying to bind it to a control's height to get something other than default system font size)

Answer 1

This way appears to work fine, not sure about the runtime layout performance though...
FYI: This does not work within the XAML Designer, only runtime
<Label
Text="X"
x:Name="foo"
BindingContext="{x:Reference Name=foo}"
FontSize="{Binding Path=Height}"
HorizontalTextAlignment="Center"
AbsoluteLayout.LayoutBounds="0.1, 0.5, 0.33, 0.66"
AbsoluteLayout.LayoutFlags="All" />

Answer 2

Not exactly related to OP question but searching "Xaml height based on another control" has hardly any results in Google so posting this in case it helps someone else.
To change the size of smaller buttons to match the size of a larger button like in the following picture
There are several ways to do this without using code behind but if the layout you are trying to use is being difficult here following is another option. To change the size of the smaller buttons without changing the binding of those controls you can give the buttons names in XAML and then do something like this in the code behind:
public HomeOpenPage ()
{
InitializeComponent ();
RefreshButton.PropertyChanging += RefreshButton_PropertyChanging;
}
private void RefreshButton_PropertyChanging(object sender, PropertyChangingEventArgs e)
{
if (RefreshButton.Width != -1)
{
var width = RefreshButton.Width;
CSVButton.WidthRequest = width;
EndButton.WidthRequest = width;
}
}
protected override void OnDisappearing()
{
RefreshButton.PropertyChanging -= RefreshButton_PropertyChanging;
base.OnDisappearing();
}