New Post: SelectAllOnGotFocus not working when DecimalUpDown control is used inside a WPF DataGrid (DataGridTemplateColumn.CellEditingTemplate)

<DataGridTemplateColumn>
<DataGridTemplateColumn.CellEditingTemplate>
   <DataTemplate>
      <Grid>
         <xctk:DecimalUpDown   FocusManager.FocusedElement="{Binding RelativeSource={RelativeSource Self}}"  ........................../>
      </Grid>
    </DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>