I have the following
For some reason the binding to MyCommand not triggering at all at my view model
Im using MvvmLight RelayCommand if it matters everywhere in my app
P.s
I tried to change Button to RadButton and the result are the same
<UserControl>
<Grid>
<telerik:RadTabControl>
<telerik:RadTabControl.AdditionalContent>
<StackPanel Orientation="horizontal"
DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AnsectorType={x:Type UserControl}}, Path=DataContext}">
<Button Command="{Binding Path=MyCommand}">
</Button>
</StackPanel>
</telerik:RadTabControl.AdditionalContent>
<telerik:RadTabControl.Items>
<telerik:RadItem>
<!-- Here everything works just fine -->
</telerik:RadItem>
</telerik:RadTabControl.Items>
</telerik:RadTabControl>
</Grid>
</UserControl>
I've tested this and the data binding works properly. You can check the attached and see if I am missing anything.