Null auto-generated x:Name fields
Setting x:Name on a series object in XAML will produce an auto-generated field in the
code-behind as usual but this field will be null at run-time. This happens because RadChart keeps its series and other internal objects in strongly typed collections in order
to avoid casting (and exceptions related to casting). It appears that there is a known bug in the Silverlight framework that causes the FindName()
method to fail when searching for the series
because they are not in an actual UIElement collection but in a custom collection that is not related to Silverlight. Currently the only way to get the series
object that was declared in XAML is to find it in the Series
property of RadChart.