How to add comments into a Xaml file in WPF?
I assume those XAML namespace declarations are in the parent tag of your control? You can’t put comments inside of another tag. Other than that, the syntax you’re using is correct.
xaml
Embed a System.String in XAML
You should use Window.Resources Here’s an example for Page, in your case it will be Window.Resources tag:
XAML Binding Groups
Try specifying you binding group as DataGrid.ItemBindingGroup instead of DataGrid.BindingGroup: And in this case you actually can omit specifying the name for your binding group. It will automatically be used for all bindings in a row.