<DataGridTemplateColumn Header="U.m." Width="70">     <DataGridTemplateColumn.CellTemplate>
 <DataTemplate> 
<TextBlock Text="{Binding unita_misura}"/> 
</DataTemplate> 
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate> 
     <DataTemplate>
         <ComboBox ItemsSource="{Binding Path=DataContext.UM,RelativeSource=               {RelativeSource FindAncestor,AncestorType={x:Type UserControl}}, UpdateSourceTrigger=    PropertyChanged,Mode=TwoWay}" SelectedItem="{Binding Path=unita_misura}">     </ComboBox>
 </DataTemplate> 
 </DataGridTemplateColumn.CellEditingTemplate> 
</DataGridTemplateColumn>