I've got the same requirement to get tooltip working like they do on WinRT. I've downloaded your example, which won't compile for me but that's not the issue. When the behavior is called is anything passed so we can identify what the person clicked on? I assume there has to bee or there's not much point in the tip. Second is do we have the option to style the tooltip with a datatemplate? Our requirement at a minimum is to have the user click on a bar on a stacking column series and get a text note that is tied to a description on the data point. On WinRT we did this with a custom object that had the X and Y values in it along with the note text. Because we could use data templates it was easy to just assign the text of the tooltip to the value of the note in the object.
I do see that the Xamarin documentation now says we can use a custom object (when I originally wrote the code it only mentioned a ChartDataPoint) but without any info on how the behavior works I'm not sure how to proceed. Also, since it's probably relevant to people trying to accomplish this with custom objects, does Xamarin SFChart still have a limitation where it can't do complex binding for the X and Y values? Our old data model looked like this:
And then for our chart we set it up like
stackingcolumnseries XBindingPath subset1.mydate YBindingPath subset1.value
stackingcolumnseries XBindingPath subset2.mydate YBindingPath subset2.value
stackingcolumnseries XBindingPath subset3.mydate YBindingPath subset3.value
and within each stacking column series in the chart there would be a tooltiptemplate using Binding Item.note for the text.
With the new release, if you use a stacking column series with a custom object does it just stack by which node it is in the series still and then by the X value? I'd love to go back to the old data model so I don't use custom objects in our WinRT app (which isn't moving to Xamarin Forms) and ChartDataPoints with our Xamarin Forms iOS and Android apps. It saves us a step in converting data which is time consuming. Plus if we could some how use the same binding concept for the tooltip template we'd already have the note tied to the series.
I guess what it comes down to is, how do we use the latest code to accomplish something like I've got above?