If you got to this point then there is probably something wrong with your design and you should reconsider it.
that being said you could traverse the visual tree and find it like this:
/// Returns the first GroupBox ancester
public DependencyObject FindAncestor(DependencyObject current)
{
current = VisualTreeHelper.GetParent(current);
while (current != null)
{
if (current is GroupBox)
{
return (T)current;
}
current = VisualTreeHelper.GetParent(current);
};
return null;
}
then go over the children and find the checked radioButton
public RadioButton FindChild<T>(DependencyObject parent)
{
// Confirm parent and childName are valid.
if (parent == null) return null;
RadioButton foundChild = null;
int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < childrenCount; i++)
{
var child = VisualTreeHelper.GetChild(parent, i);
// If the child is not of the request child type child
var childType = child as radioButton;
if (childType == null)
{
// recursively drill down the tree
foundChild = FindChild(child);
// If the child is found, break so we do not overwrite the found child.
if (foundChild != null) return foundChild ;
}
else if (childName.IsChecked == true)
{
return foundChild;
}
}
return null;
}